In humans, overdosage has been associated with vomiting, facial flushing, cheilosis, abdominal pain, headache, dizziness, and ataxia. These symptoms quickly resolve without apparent residual effects.
ABSORICA causes serious birth defects at any dosage (see BOXED
The oral LD50 of isotretinoin is greater than 4000 mg/kg in rats and mice ( > 600 times the recommended clinical dose of 1.0 mg/kg/day after normalization of the rat dose for total body surface area and > 300 times the recommended clinical dose of 1.0 mg/kg/day after normalization of the mouse dose for total body surface area) and is approximately 1960 mg/kg in rabbits (653 times the recommended clinical dose of 1.0 mg/kg/day after normalization for total body surface area). In humans, overdosage has been associated with vomiting, facial flushing, cheilosis, abdominal pain, headache, dizziness, and ataxia. These symptoms quickly resolve without apparent residual effects.
Flexresan (isotretinoin) causes serious birth defects at any dosage (see Boxed
Isotretinoin is a derivative of vitamin A. Although the acute toxicity of isotretinoin is low, signs of hypervitaminosis A could appear in cases of accidental overdose. Manifestations of acute vitamin A toxicity include severe headache, nausea or vomiting, drowsiness, irritability and pruritus. Signs and symptoms of accidental or deliberate overdosage with isotretinoin would probably be similar. These symptoms would be expected to be reversible and to subside without the need for treatment.
Flexresan is a derivative of vitamin A. Although the acute toxicity of Flexresan is low, signs of hypervitaminosis A could appear in cases of accidental overdose. Manifestations of acute vitamin A toxicity include severe headache, nausea or vomiting, drowsiness, irritability and pruritus. Signs and symptoms of accidental or deliberate overdosage with Flexresan would probably be similar. These symptoms would be expected to be reversible and to subside without the need for treatment.
Symptoms and signs
Oral ingestion of a 30g tube of topical isotretinoin would result in less exposure than achieved with the recommended dosage of oral isotretinoin. Consequently, the theoretical occurrence of symptoms of overdosage (e.g. hypervitaminosis A) is highly unlikely.
The gel formulation contains more than 95% ethanol. Systemic absorption of this should be considered in the event of oral ingestion.
Treatment
Further management should be as clinically indicated or as recommended by the national poisons centre, where available.
ABSORICA can cause fetal harm when administered to a pregnant woman. Major congenital malformations, spontaneous abortions, and premature births have been documented following pregnancy exposure to isotretinoin in any amount and even for short periods of time. ABSORICA is contraindicated in females who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, treatment should be discontinued and the patient should be apprised of the potential hazard to the fetus.
HypersensitivityHypersensitivity to this product (or Vitamin A, given the chemical similarity to isotretinoin) or to any of its components.
PregnancyCategory X. See Boxed CONTRAINDICATIONS AND WARNINGS.
Allergic ReactionsFlexresan (isotretinoin) is contraindicated in patients who are hypersensitive to this medication or to any of its components. Flexresan (isotretinoin) should not be given to patients who are sensitive to parabens, which are used as preservatives in the gelatin capsule (see PRECAUTIONS: Hypersensitivity).
Isotretinoin is contraindicated in women who are pregnant or breastfeeding.
Isotretinoin is contraindicated in women of childbearing potential unless all of the conditions of the Pregnancy Prevention Programme are met.
Flexresan 20 mg contains soya oil, partially hydrogenated soya oil, and hydrogenated soya oil. Therefore, Flexresan 20 mg is contraindicated in patients allergic to peanut or soya.Isotretinoin is also contraindicated in patients
- With hepatic insufficiency
- With excessively elevated blood lipid values
- With hypervitaminosis A
- Receiving concomitant treatment with tetracyclines.
Flexresan is contraindicated in women who are pregnant or breast-feeding.
Flexresan is contraindicated in women of childbearing potential unless all of the conditions of the Pregnancy Prevention Programme are met.
Flexresan is also contraindicated in patients
With hepatic insufficiency
With excessively elevated blood lipid values
With hypervitaminosis A
With hypersensitivity to Flexresan or to any of the excipients
Receiving concomitant treatment with tetracyclines
Allergic to peanut or soya oil as Flexresan contains soya-bean oil
Flexresan Gel is contraindicated in pregnancy and lactation.
Not applicable.
The following adverse reactions with ABSORICA or other isotretinoin products are described in more detail in other sections of the labeling:
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of ABSORICA cannot be directly compared to rates in clinical trials of other drugs and may not reflect the rates observed in practice.
The adverse reactions listed below reflect both clinical experience with ABSORICA, and consider other adverse reactions that are known from clinical trials and the post-marketing surveillance with oral isotretinoin. The relationship of some of these events to isotretinoin therapy is unknown. Many of the side effects and adverse events seen in patients receiving isotretinoin are similar to those described in patients taking very high doses of vitamin A (dryness of the skin and mucous membranes, e.g., of the lips, nasal passage, and eyes).
Dose RelationshipCheilitis and hypertriglyceridemia are adverse reactions that are usually dose related. Most adverse reactions reported in clinical trials with isotretinoin were reversible when therapy was discontinued; however, some persisted after cessation of therapy.
Body as a WholeThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): fatigue, irritability, pain. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: allergic reactions, including vasculitis, systemic hypersensitivity, edema, lymphadenopathy, weight loss.
CardiovascularThe following adverse reactions have been reported with isotretinoin: vascular thrombotic disease, stroke, palpitation, tachycardia.
Endocrine/Metabolism and NutritionalThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): decreased appetite, weight fluctuation, hyperlipidaemia. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: hypertriglyceridemia, alterations in blood sugar.
GastrointestinalThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): lip dry, chapped lips, cheilitis, nausea, constipation, diarrhea, abdominal pain, vomiting. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: inflammatory bowel disease, hepatitis, pancreatitis, bleeding and inflammation of the gums, colitis, esophagitis/esophageal ulceration, ileitis, and other nonspecific gastrointestinal symptoms.
HematologicThe following adverse reactions have been reported with isotretinoin: allergic reactions, anemia, thrombocytopenia, neutropenia, rare reports of agranulocytosis.
Infections and infestationsThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): nasopharyngitis, hordeolum, upper respiratory tract infection. In addition to the above adverse reactions, the following adverse reaction has been reported with isotretinoin: infections (including disseminated herpes simplex).
Laboratory AbnormalitiesThe following changes in laboratory tests have been noted in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): blood creatine phosphokinase (CPK) increased, blood triglycerides increased, alanine aminotransferase (SGPT) increased, aspartate aminotransferase (SGOT) increased, gamma-glutamyltransferase (GGTP) increased, blood cholesterol increased, low density lipoprotein (LDL) increased, white blood cell count decreased, blood alkaline phosphatase increased, blood bilirubin increased, blood glucose increased, high density lipopoprotein (HDL) decreased, bone mineral density decreased. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: increased LDH, elevation of fasting blood sugar, hyperuricemia, decreases in red blood cell parameters, decreases in white blood cell counts (including severe neutropenia and rare reports of agranulocytosis), elevated sedimentation rates, elevated platelet counts, thrombocytopenia, white cells in the urine, proteinuria, microscopic or gross hematuria.
Musculoskeletal and Connective TissueThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): decreases in bone mineral density, musculoskeletal symptoms (sometimes severe) including back pain, athralgia, musculoskeletal discomfort, musculoskeletal pain, neck pain, pain in extremity, myalgia, musculoskeletal stiffness. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: skeletal hyperostosis, calcification of tendons and ligaments, premature epiphyseal closure, tendonitis, arthritis, transient pain in the chest, and rare reports of rhabdomyolysis.
NeurologicalThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): headache, syncope. In addition to the above adverse reactions, other adverse reactions reported with isotretinoin include: pseudotumor cerebri, dizziness, drowsiness, lethargy, malaise, nervousness, paresthesias, seizures, stroke, weakness.
PsychiatricThe following adverse reactions have been reported in clinical trials conducted with ABSORICA and a generic product of Accutane® (isotretinoin): suicidal ideation, insomnia, anxiety, depression, irritability, panic attack, anger, euphoria, violent behaviors, emotional instability. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: suicide attempts, suicide, aggression, psychosis and hallucination auditory. Of the patients reporting depression, some reported that the depression subsided with discontinuation of therapy and recurred with reinstitution of therapy.
Reproductive SystemThe following adverse reaction has been reported with isotretinoin: abnormal menses.
RespiratoryThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): epistaxis, nasal dryness. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: bronchospasms (with or without a history of asthma), respiratory infection, voice alteration.
Skin and Subcutaneous TissueThe following adverse reactions have been reported in a clinical trial conducted with ABSORICA and a generic product of Accutane® (isotretinoin): dry skin, dermatitis, eczema, rash, dermatitis contact, alopecia, pruritus, sunburn, erythema. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: acne fulminans, alopecia (which in some cases persists), bruising, dry nose, eruptive xanthomas, erythema multiforme, flushing, fragility of skin, hair abnormalities, hirsutism, hyperpigmentation and hypopigmentation, nail dystrophy, paronychia, peeling of palms and soles, photoallergic/photosensitizing reactions, pruritus, pyogenic granuloma, rash (including facial erythema, seborrhea, and eczema), Stevens-Johnson syndrome, sunburn susceptibility increased, sweating, toxic epidermal necrolysis, urticaria, vasculitis (including Wegener's granulomatosis), abnormal wound healing (delayed healing or exuberant granulation tissue with crusting).
Special SensesHearing: The following adverse reactions have been reported with isotretinoin: tinnitus and hearing impairment.
Ocular: The following adverse reactions have been reported in clinical trials conducted with ABSORICA and a generic product of Accutane® (isotretinoin): dry eye, visual acuity reduced, vision blurred, eye pruritis, eye irritation, asthenopia, decreased night vision, ocular hyperemia, increased lacrimation, and conjunctivitis. In addition to the above adverse reactions, the following adverse reactions have been reported with isotretinoin: corneal opacities, decreased night vision which may persist, cataracts, color vision disorder, conjunctivitis, eyelid inflammation, keratitis, optic neuritis, photobia, visual disturbances.
Renal and UrinaryThe following adverse reactions have been reported in clinical trials conducted with isotretinoin: glomerulonephritis, nonspecific urogenital findings.
Clinical Trials and Postmarketing SurveillanceThe adverse reactions listed below reflect the experience from investigational studies of Flexresan (isotretinoin) , and the postmarketing experience. The relationship of some of these events to Flexresan (isotretinoin) therapy is unknown. Many of the side effects and adverse reactions seen in patients receiving Flexresan (isotretinoin) are similar to those described in patients taking very high doses of vitamin A (dryness of the skin and mucous membranes, eg, of the lips, nasal passage, and eyes).
Dose RelationshipCheilitis and hypertriglyceridemia are usually dose related. Most adverse reactions reported in clinical trials were reversible when therapy was discontinued; however, some persisted after cessation of therapy (see WARNINGS and ADVERSE REACTIONS).
Body as a Wholeallergic reactions, including vasculitis, systemic hypersensitivity (see PRECAUTIONS: Hypersensitivity), edema, fatigue, lymphadenopathy, weight loss
Cardiovascularpalpitation, tachycardia, vascular thrombotic disease, stroke
Endocrine/Metabolichypertriglyceridemia (see WARNINGS: Lipids), alterations in blood sugar levels (see PRECAUTIONS: Laboratory Tests)
Gastrointestinalinflammatory bowel disease (see WARNINGS: Inflammatory Bowel Disease), hepatitis (see WARNINGS: Hepatotoxicity), pancreatitis (see WARNINGS: Lipids), bleeding and inflammation of the gums, colitis, esophagitis/esophageal ulceration, ileitis, nausea, other nonspecific gastrointestinal symptoms
Hematologicallergic reactions (see PRECAUTIONS: Hypersensitivity), anemia, thrombocytopenia, neutropenia, rare reports of agranulocytosis (see PATIENT INFORMATION). See PRECAUTIONS: Laboratory Tests for other hematological parameters.
Musculoskeletalskeletal hyperostosis, calcification of tendons and ligaments, premature epiphyseal closure, decreases in bone mineral density (see WARNINGS: Skeletal), musculoskeletal symptoms (sometimes severe) including back pain, myalgia, and arthralgia (see PATIENT INFORMATION), transient pain in the chest (see PATIENT INFORMATION ), arthritis, tendonitis, other types of bone abnormalities, elevations of CPK/rare reports of rhabdomyolysis (see PRECAUTIONS: Laboratory Tests).
Neurologicalpseudotumor cerebri (see WARNINGS: Pseudotumor Cerebri), dizziness, drowsiness, headache, insomnia, lethargy, malaise, nervousness, paresthesias, seizures, stroke, syncope, weakness
Psychiatricsuicidal ideation, suicide attempts, suicide, depression, psychosis, aggression, violent behaviors (see WARNINGS: Psychiatric Disorders), emotional instability
Of the patients reporting depression, some reported that the depression subsided with discontinuation of therapy and recurred with reinstitution of therapy.
Reproductive Systemabnormal menses
Respiratorybronchospasms (with or without a history of asthma), respiratory infection, voice alteration
Skin and Appendagesacne fulminans, alopecia (which in some cases persists), bruising, cheilitis (dry lips), dry mouth, dry nose, dry skin, epistaxis, eruptive xanthomas,7 erythema multiforme, flushing, fragility of skin, hair abnormalities, hirsutism, hyperpigmentation and hypopigmentation, infections (including disseminated herpes simplex), nail dystrophy, paronychia, peeling of palms and soles, photoallergic/photosensitizing reactions, pruritus, pyogenic granuloma, rash (including facial erythema, seborrhea, and eczema), Stevens-Johnson syndrome, sunburn susceptibility increased, sweating, toxic epidermal necrolysis, urticaria, vasculitis (including Wegener's granulomatosis; see PRECAUTIONS: Hypersensitivity), abnormal wound healing (delayed healing or exuberant granulation tissue with crusting; see PATIENT INFORMATION)
Special SensesHearing - hearing impairment (see WARNINGS: Hearing Impairment), tinnitus.
Vision- corneal opacities (see WARNINGS: Corneal Opacities), decreased night vision which may persist (see WARNINGS: Decreased Night Vision), cataracts, color vision disorder, conjunctivitis, dry eyes, eyelid inflammation, keratitis, optic neuritis, photophobia, visual disturbances
Urinary Systemglomerulonephritis (see PRECAUTIONS: Hypersensitivity), nonspecific urogenital findings (see PRECAUTIONS: Laboratory Tests for other urological parameters)
LaboratoryElevation of plasma triglycerides (see WARNINGS: Lipids), decrease in serum high-density lipoprotein (HDL) levels, elevations of serum cholesterol during treatment
Increased alkaline phosphatase, SGOT (AST), SGPT (ALT), GGTP or LDH (see WARNINGS: Hepatotoxicity)
Elevation of fasting blood sugar, elevations of CPK (see PRECAUTIONS: Laboratory Tests), hyperuricemia
Decreases in red blood cell parameters, decreases in white blood cell counts (including severe neutropenia and rare reports of agranulocytosis; see PATIENT INFORMATION), elevated sedimentation rates, elevated platelet counts, thrombocytopenia
White cells in the urine, proteinuria, microscopic or gross hematuria
Summary of safety profile
Some of the side effects associated with the use of isotretinoin are dose-related. The side effects are generally reversible after altering the dose or discontinuation of treatment, however some may persist after treatment has stopped. The following symptoms are the most commonly reported undesirable effects with isotretinoin: dryness of the skin, dryness of the mucosae e.g. of the lips (cheilitis), the nasal mucosa (epistaxis) and the eyes (conjunctivitis).
Tabulated list of adverse reactions
The incidence of the adverse reactions calculated from pooled clinical trial data involving 824 patients and from post-marketing data are presented in the table below. The adverse reactions are listed below by MedDRA system organ class (SOC) and categories of frequency. Frequency categories are defined as Very common (>1/10), Common (>1/100 to <1/10), Uncommon (>1/1,000 to <1/100), Rare (>1/10,000 to <1/1,000), Very rare (>1/10,000 to <1/1,000) and not known (cannot be estimated from the available data). Within each frequency grouping and SOC, adverse reactions are presented in order of decreasing seriousness.
Table 1 Tabulated list of adverse reactions in patients treated with isotretinoin
| System Organ Class | Very Common | Common | Rare | Very Rare | Not known* |
| Infections | Gram positive (mucocutaneous) bacterial infection | ||||
| Blood and lymphatic system disorders | Thrombocytopenia, anaemia, thrombocytosis, red blood cell sedimentation rate increased | Neutropenia | Lymphadenopathy | ||
| Immune system disorders | Anaphylactic reactions, hypersensitivity, allergic skin reaction | ||||
| Metabolism and nutrition disorders | Diabetes mellitus, hyperuricaemia | ||||
| Psychiatric disorders | Depression, depression aggravated, aggressive tendencies, anxiety, mood alterations. | Suicide, suicide attempt, suicidal ideation, psychotic disorder, abnormal behaviour | |||
| Nervous system disorders | Headache | Benign intracranial hypertension, convulsions, drowsiness, dizziness | |||
| Eye disorders | Blepharitis, conjunctivitis, dry eye, eye irritation | Papilloedema (as sign of benign intracranial hypertension), cataract, colour blindness (colour vision deficiencies), contact lens intolerance, corneal opacity, decreased night vision, keratitis, photophobia, visual disturbances, blurred vision. | |||
| Ear and labyrinth disorders | Hearing impaired | ||||
| Vascular disorders | Vasculitis (for example Wegener's granulomatosis, allergic vasculitis) | ||||
| Respiratory, thoracic and mediastinal disorders | Nasopharyngitis,epistaxis, nasal dryness | Bronchospasm (particularly in patients with asthma), hoarseness | |||
| Gastrointestinal disorders | Inflammatory bowel disease, colitis, ileitis, pancreatitis, gastrointestinal haemorrhage, haemorrhagic diarrhoea, nausea dry throat | ||||
| Hepatobiliary disorders | Transaminase increased | Hepatitis | |||
| Skin and subcutaneous tissues disorders | Pruritus, rash erythematous, dermatitis, cheilitis, dry skin, localised exfoliation, skin fragility (risk of frictional trauma) | Alopecia | Acne fulminans, acne aggravated (acne flare), erythema (facial), exanthema, hair disorders, hirsutism, nail dystrophy, paronychia, photosensitivity reaction, pyogenic granuloma, skin hyperpigmentation, sweating increased | Erythema multiforme, Stevens-Johnson Syndrome, toxic epidermal necrolysis | |
| Musculo-skeletal and connective tissue disorders | Arthralgia, myalgia, back pain (particularly in children and adolescent patients) | Arthritis, calcinosis (calcification of ligaments and tendons), epiphyses premature fusion, exostosis, (hyperostosis), reduced bone density, tendonitis | Rhabdomyolysis | ||
| Renal and urinary disorders | Glomerulonephritis | ||||
| Reproductive system and breast disorders | Sexual dysfunction including erectile dysfunction and decreased libido | ||||
| General disorders and administration site conditions | Granulation tissue (increased formation of), malaise | ||||
| Investigations | Blood triglycerides increased, high density lipoprotein decreased | Blood cholesterol increased, blood glucose increased, haematuria, proteinuria | Blood creatine phosphokinase increased |
* cannot be estimated from the available data
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
Summary of safety profile
Some of the side effects associated with the use of Flexresan are dose-related. The side effects are generally reversible after altering the dose or discontinuation of treatment, however some may persist after treatment has stopped. The following symptoms are the most commonly reported undesirable effects with Flexresan: dryness of the mucosae e.g. of the lips (cheilitis), the nasal mucosa (epistaxis), and the eyes (conjunctivitis), dryness of the skin.
Tabulated list of adverse reactions
The incidence of the adverse reactions calculated from pooled clinical trial data involving 824 patients and from postmarketing data are presented in the table below. The adverse reactions are listed below by MedDRA system organ class (SOC) and categories of frequency. Frequency categories are defined as very common (>1/10), common (>1/100 to <1/10), uncommon (>1/1,000 to <1/100), rare (>1/10,000 to <1/1,000), very rare (>1/10,000 to <1/1,000) and not known (cannot be estimated from the available data). Within each frequency grouping and SOC, adverse reactions are presented in order of decreasing seriousness.
Table 1 Tabulated list of adverse reactions in patients treated with Flexresan
| System Organ Class | Very Common | Common | Rare | Very Rare | Not Known |
| Infections and infestations: | Gram positive (mucocutaneous) bacterial infection | ||||
| Blood and lymphatic system disorders: | Anaemia, Red blood cell sedimentation rate increased, Thrombocytopenia, Thrombocytosis | Neutropenia | Lymphadenopathy |
| |
| Immune system disorders: | Allergic skin reaction, Anaphylactic reactions, Hypersensitivity | ||||
| Metabolism and nutrition disorders: | Diabetes mellitus, Hyperuricaemia | ||||
| Psychiatric disorders: | Depression including aggravation of pre-existing depression Aggressive tendencies, Anxiety, Mood Alterations | Abnormal behaviour, Psychotic disorder, Suicidal ideation, Suicide attempt, Suicide | |||
| Nervous system disorders: | Headache | Benign intracranial hypertension Convulsions, Drowsiness, Dizziness | |||
| Eye disorders: | Blepharitis, Conjunctivitis, Dry eye, Eye irritation | Blurred vision, Cataract, Colour blindness (colour vision deficiencies), Contact lens intolerance, Corneal opacity, Decreased night vision, Keratitis, Papilloedema (as sign of benign intracranial hypertension), Photophobia, Visual disturbances | |||
| Ear and labyrinth disorders: | Hearing impaired | ||||
| Vascular disorders: | Vasculitis (for example Wegener's granulomatosis, allergic vasculitis) | ||||
| Respiratory, thoracic and mediastinal disorders: | Epistaxis, Nasal dryness, Nasopharyngitis | Bronchospasm (particularly in patients with asthma), Hoarseness | |||
| Gastrointestinal disorders: | Colitis, Ileitis, Dry throat, Gastrointestinal haemorrhage, haemorrhagic diarrhoea and inflammatory bowel disease, Nausea, Pancreatitis | ||||
| Hepatobiliary disorders: | Transaminase increased | Hepatitis | |||
| Skin and subcutaneous tissues disorders: | Cheilitis, Dermatitis, Dry skin, Localised exfoliation, Pruritus, Rash erythematous, Skin fragility (and risk of frictional trauma) | Alopecia | Acne fulminans, Acne aggravated (acne flare), Erythema (facial), Exanthema, Hair disorders, Hirsutism, Nail dystrophy, Paronychia, Photosensitivity reaction, Pyogenic granuloma, Skin hyperpigmentation, Sweating increased | Erythema multiforme, Stevens-Johnson Syndrome, toxic epidermal necrolysis. | |
| Musculoskeletal and connective tissue disorders: | Arthralgia, Myalgia, Back pain (particularly in children and adolescent patients) | Arthritis, Calcinosis (calcification of ligaments and tendons), Epiphyses premature fusion, Exostosis, (hyperostosis), Reduced bone density, Tendonitis, Rhabdomyolysis | |||
| Renal and urinary disorders: | Glomerulonephritis | ||||
| Reproductive system and breast disorders | Sexual dysfunction including erectile dysfunction and decreased libido | ||||
| General disorders and administration site conditions: | Granulation tissue (increased formation of), Malaise | ||||
| Investigations: | Blood triglycerides increased, High density lipoprotein decreased | Blood cholesterol increased, Blood glucose increased, Haematuria, Proteinuria | Blood creatine phosphokinase increased |
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.
The frequency of adverse reactions listed below is defined using the following convention: very common (> 1/10); common (> 1/100, < 1/10); uncommon (> 1/1,000, < 1/100); rare (> 1/10,000, < 1/1,000); very rare (< 1/10,000). Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.
Skin and subcutaneous tissue disorders
| Very common: | Application site erythema, skin exfoliation, skin pain, application site pruritus, skin irritation, skin tenderness, skin burning sensation, application site stinging, dry skin |
Post-marketing data:
The following adverse drug reactions are based on post-marketing reports. Since these reports are from a population of uncertain size and are subject to confounding factors, it is not possible to reliably estimate their frequency, however in reality the following reactions are rarely seen.
Skin and subcutaneous tissue disorders
| Not known: | Skin hyperpigmentation, skin hypopigmentation, photosensitivity reaction |
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.
Acute toxicity
The acute oral toxicity of isotretinoin was determined in various animal species. LD50 is approximately 2000 mg/kg in rabbits, approximately 3000 mg/kg in mice, and over 4000 mg/kg in rats.
Chronic toxicity
A long-term study in rats over 2 years (isotretinoin dosage 2, 8 and 32 mg/kg/d) produced evidence of partial hair loss and elevated plasma triglycerides in the higher dose groups. The side effect spectrum of isotretinoin in the rodent thus closely resembles that of vitamin A, but does not include the massive tissue and organ calcifications observed with vitamin A in the rat. The liver cell changes observed with vitamin A did not occur with isotretinoin.
All observed side effects of hypervitaminosis A syndrome were spontaneously reversible after withdrawal of isotretinoin. Even experimental animals in a poor general state had largely recovered within 1-2 weeks.
Teratogenicity
Like other vitamin A derivatives, isotretinoin has been shown in animal experiments to be teratogenic and embryotoxic.
4, ).Mutagenicity
Isotretinoin has not been shown to be mutagenic in in vitro or in vivo animal tests.
Acute toxicity
The acute oral toxicity of Flexresan was determined in various animal species. LD50 is approximately 2000 mg/kg in rabbits, approximately 3000 mg/kg in mice, and over 4000 mg/kg in rats.
Chronic toxicity
A long-term study in rats over 2 years (Flexresan dosage 2, 8 and 32 mg/kg/d) produced evidence of partial hair loss and elevated plasma triglycerides in the higher dose groups. The side effect spectrum of Flexresan in the rodent thus closely resembles that of vitamin A, but does not include the massive tissue and organ calcifications observed with vitamin A in the rat. The liver cell changes observed with vitamin A did not occur with Flexresan.
All observed side effects of hypervitaminosis A syndrome were spontaneously reversible after withdrawal of Flexresan. Even experimental animals in a poor general state had largely recovered within 1-2 weeks.
Teratogenicity
Like other vitamin A derivatives, Flexresan has been shown in animal experiments to be teratogenic and embryotoxic.
4 ).Mutagenicity
Flexresan has not been shown to be mutagenic nor carcinogenic in in vitro or in vivo animal tests respectively.
Carcinogenesis/Mutagenesis
In a carcinogenicity study in Fischer 344 rats given oral isotretinoin up to 32 mg/kg/day, there was an increased incidence of phaeochromocytomas relative to controls in both sexes at 32 mg/kg/day and in males at 8 mg/kg/day. Given the high rate of spontaneous rate of occurrence of phaeochromoyctoma in Fischer 344 rats, the relevance of this tumour to humans is uncertain.
Studies in hairless mice suggest that concurrent dermal exposure to isotretinoin at dose levels up to 500 mg/kg may enhance the tumorigenic potential of UV irradiation. The significance of these studies to humans is not clear.
The mutagenic potential of isotretinoin was evaluated in the Ames assay with and without S9 metabolic activation and in the Chinese hamster lung cell for chromosome aberrations, both of which were negative.
Reproductive Toxicology
Fertility
In rats, no adverse effects on gonadal function, fertility, conception rate, gestation or parturition were observed at oral dose levels of isotretinoin up to 32 mg/kg/day.
In dogs, testicular atrophy was noted after approximately 30 weeks at isotretinoin dose levels of 20 or 60 mg/kg/day. However, in studies of men receiving oral isotretinoin, no significant effects have been seen on semen parameters.
Pregnancy
Reproduction studies conducted in rabbits using isotretinoin gel applied topically at up to 60 times the human dose have revealed no harm to the foetus.
Topical application of high doses of tretinoin (an isomer of isotretinoin) induces maternal toxicity, which limits the maximum dose to a level potentially below that associated with embryofoetal alterations by other routes of administration.
In one study, topical doses of a 0.1% ethanol solution, given to Wistar rats through gestational days (GDs) 6 to 16, were not tolerated at 10 mg/kg/day, causing severe local and systemic maternal toxicity. Offspring of dams receiving 5 mg/kg weighed significantly less than those of controls. Maternal toxicity (reduced weight gain and food consumption) was also evident at doses of 2.5 mg/kg/day or more. A significant increase in the occurrence of supernumerary ribs was observed at this dose, a result thought to be nonspecific or maternally mediated.
Topical administration of tretinoin at a dose of 10.5 mg/kg/day for 3 days to intact skin of hamsters on GDs 7, 8, and 9 resulted in erythema and/or epidermal hyperplasia at the site of application, but did not cause a significant teratogenic response.
Topical administration of 5 g 0.05% tretinoin ointment (corresponding to a dose of ~ 10 mg/kg) to the shaved backs of pregnant rats on GD 12 resulted in some retinoid-specific patterns of anomalies (humerus short 9%, radius bent 6%, ribs wavy 80%). This dose was ~100 fold that expected in humans.
ABSORICA is a retinoid indicated for the treatment of severe recalcitrant nodular acne in patients 12 years of age and older. Nodules are inflammatory lesions with a diameter of 5 mm or greater. The nodules may become suppurative or hemorrhagic. “Severe,” by definition, means “many” as opposed to “few or several” nodules. Because of significant adverse reactions associated with its use, ABSORICA should be reserved for patients with multiple severe nodular acne who are unresponsive to conventional therapy, including systemic antibiotics. In addition, ABSORICA is indicated only for those female patients who are not pregnant, because ABSORICA can cause severe birth defects.
Limitations of UseA single course of therapy for 15 to 20 weeks has been shown to result in complete and prolonged remission of disease in many patients. If a second course of therapy is needed, it should not be initiated until at least 8 weeks after completion of the first course, because experience with isotretinoin has shown that patients may continue to improve following treatment with isotretinoin. The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth.
As a part of the iPLEDGE program, ABSORICA may only be administered to patients enrolled in the program.
Severe Recalcitrant Nodular AcneFlexresan (isotretinoin) is indicated for the treatment of severe recalcitrant nodular acne. Nodules are inflammatory lesions with a diameter of 5 mm or greater. The nodules may become suppurative or hemorrhagic. “Severe,” by definition,2 means “many” as opposed to “few or several” nodules. Because of significant adverse effects associated with its use, Flexresan (isotretinoin) should be reserved for patients with severe nodular acne who are unresponsive to conventional therapy, including systemic antibiotics. In addition, Flexresan (isotretinoin) is indicated only for those female patients who are not pregnant, because Flexresan (isotretinoin) can cause severe birth defects (see Boxed CONTRAINDICATIONS AND WARNINGS).
A single course of therapy for 15 to 20 weeks has been shown to result in complete and prolonged remission of disease in many patients.1,3,4 If a second course of therapy is needed, it should not be initiated until at least 8 weeks after completion of the first course, because experience has shown that patients may continue to improve while off Flexresan (isotretinoin). The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth (see WARNINGS: Skeletal: Bone Mineral Density, Hyperostosis, and Premature Epiphyseal Closure).
Severe forms of acne (such as nodular or conglobate acne or acne at risk of permanent scarring) resistant to adequate courses of standard therapy with systemic anti-bacterials and topical therapy.
Severe forms of acne (such as nodular or conglobate acne or acne at risk of permanent scarring) resistant to adequate courses of standard therapy with systemic antibacterials and topical therapy.
Flexresan Gel is intended for use in the treatment of mild to moderate inflammatory and non-flammatory acne vulgaris.
The pharmacodynamics of ABSORICA are unknown.
Pharmacotherapeutic group: Retinoid for treatment of acne.
ATC code: D10B A01
Mechanism of action
Isotretinoin is a stereoisomer of all-trans retinoic acid (tretinoin). The exact mechanism of action of isotretinoin has not yet been elucidated in detail, but it has been established that the improvement observed in the clinical picture of severe acne is associated with suppression of sebaceous gland activity and a histologically demonstrated reduction in the size of the sebaceous glands. Furthermore, a dermal anti-inflammatory effect of isotretinoin has been established.
Clinical efficacy and safety
Hypercornification of the epithelial lining of the pilosebaceous unit leads to shedding of corneocytes into the duct and blockage by keratin and excess sebum. This is followed by formation of a comedone and, eventually, inflammatory lesions. Isotretinoin inhibits proliferation of sebocytes and appears to act in acne by re-setting the orderly program of differentiation. Sebum is a major substrate for the growth of Propionibacterium acnes so that reduced sebum production inhibits bacterial colonisation of the duct.
Pharmacotherapeutic group: Retinoid for the treatment of acne, ATC code: D10BA01
Mechanism of action
Flexresan is a stereoisomer of all-trans retinoic acid (tretinoin). The exact mechanism of action of Flexresan has not yet been elucidated in detail, but it has been established that the improvement observed in the clinical picture of severe acne is associated with suppression of sebaceous gland activity and a histologically demonstrated reduction in the size of the sebaceous glands. Furthermore, a dermal anti-inflammatory effect of Flexresan has been established.
Clinical efficacy and safety
Hypercornification of the epithelial lining of the pilosebaceous unit leads to shedding of corneocytes into the duct and blockage by keratin and excess sebum. This is followed by formation of a comedone and, eventually, inflammatory lesions. Flexresan inhibits proliferation of sebocytes and appears to act in acne by re-setting the orderly programme of differentiation. Sebum is a major substrate for the growth of Propionibacterium acnes so that reduced sebum production inhibits bacterial colonisation of the duct.
Pharmacotherapeutic group: retinoids for topical use in acne, isotretinoin.
ATC Code: D10A D04
Mechanism of action
Isotretinoin is structurally and pharmacologically related to vitamin A which regulates epithelial cell growth and differentiation. It is thought that topically applied isotretinoin acts in a comparable way to its stereoisomer, tretinoin, and:
- stimulates mitosis in the epidermis
- reduces intercelluar cohesion in the stratum corneum
- contests the hyperkeratosis characteristic of acne vulgaris
- aids desquamation, preventing the formation of lesions
- mediates an increased production of less cohesive epidermal sebaceous cells, which appears to promote the initial expulsion of comedones and their subsequent prevention.
Isotretinoin has topical anti-inflammatory actions. Topically applied isotretinoin inhibits leukotriene-B4-induced migration of polymorphonuclear leukocytes, which accounts for topical isotretinoin's anti-inflammatory action. A significant inhibition was produced by topically applied isotretinoin but only a weak inhibition by topical tretinoin. This may account for the reduced rebound effect seen with topical isotretinoin when compared with topical tretinoin.
Pharmacodynamic effects
The pharmacological action of isotretinoin remains to be fully elucidated.
Isotretinoin binds to the 3 retinoic acid receptors (RAR) alpha, beta and gamma with less affinity and is unable to bind to retinoid X receptors (RXR) and the retinoic acid cellular receptor (CRABP).
There are studies which show similar activity to systemic actions when administered topically. Inhibition of sebum production by topical isotretinoin has been demonstrated in the ears and flank organs of the Syrian hamster. Application of isotretinoin to the ear for 15 days led to a 50% reduction in sebaceous gland size, and application to the flank organ resulted in a 40% reduction. Topical application of isotretinoin has also been shown to have an effect on the epidermal differentiation of rhino mouse skin. Reduction in the size of the utriculi or superficial cysts leading to normal looking follicles was a predominant feature of isotretinoin treatment and has been used to quantify the antikeratinising effects of isotretinoin.
Due to its high lipophilicity, oral absorption of isotretinoin is enhanced when given with a high-fat meal. ABSORICA is bioequivalent to Accutane® (isotretinoin) capsule when both drugs are taken with a high-fat meal. ABSORICA is more bioavailable than Accutane® (isotretinoin) capsules when both drugs are taken fasted; the AUC0-t of ABSORICA is approximately 83% greater than that of Accutane®. ABSORICA is therefore not interchangeable with generic products of Accutane®.
A single dose two-way crossover pharmacokinetic trial was conducted in 14 healthy adult male subjects comparing ABSORICA 40 mg (1 x 40 mg capsules), dosed under fasted and fed conditions. Under fed conditions after a high-fat meal, it was observed that the mean AUC0-t and Cmax were approximately 50% and 26% higher, than that observed under fasting conditions (Table 2). The observed elimination half-life (T½) was slightly lower in the fed state versus fasted. The time to peak concentration (Tmax) increased with food and this may be related to a longer absorption phase.
Table 2: Pharmacokinetic parameters of ABSORICA mean (%CV) following administration of 40 mg strength, N=14
| ABSORICA (1 x 40 mg capsules) | AUC0-t (ng x hr/mL) | Cmax (ng/mL) | Tmax (hr) | T½ (hr) |
| Fed | 6095 (26 %) | 395 (39 %) | 6.4 (47 %) | 22 (25 %) |
| Fasted | 4055 (20 %) | 314 (26 %) | 2.9 (34 %) | 24 (28 %) |
Published clinical literature has shown that there is no difference in the pharmacokinetics of isotretinoin between patients with nodular acne and healthy subjects with normal skin.
DistributionIsotretinoin is more than 99.9% bound to plasma proteins, primarily albumin.
MetabolismFollowing oral administration of isotretinoin, at least three metabolites have been identified in human plasma: 4-oxo-isotretinoin, retinoic acid (tretinoin), and 4-oxo-retinoic acid (4-oxo-tretinoin). Retinoic acid and 13-cis-retinoic acid are geometric isomers and show reversible interconversion. The administration of one isomer will give rise to the other. Isotretinoin is also irreversibly oxidized to 4-oxo-isotretinoin, which forms its geometric isomer 4-oxo-tretinoin.
After a single 40 mg oral dose of ABSORICA to 57 healthy adult subjects, concurrent administration of food increased the extent of formation of all metabolites in plasma when compared to the extent of formation under fasted conditions.
All of these metabolites possess retinoid activity that is in some in vitro models more than that of the parent isotretinoin. However, the clinical significance of these models is unknown.
In vitro studies indicate that the primary P450 isoforms involved in isotretinoin metabolism are 2C8, 2C9, 3A4, and 2B6. Isotretinoin and its metabolites are further metabolized into conjugates, which are then excreted in urine and feces.
EliminationFollowing oral administration of an 80 mg dose of 14C-isotretinoin as a liquid suspension, 14C-activity in blood declined with a half-life of 90 hours. The metabolites of isotretinoin and any conjugates are ultimately excreted in the feces and urine in relatively equal amounts (total of 65% to 83%).
After a single 40 mg (2 x 20 mg) oral dose of ABSORICA to 57 healthy adult subjects under fed conditions, the mean ± SD elimination half-lives (T½) of isotretinoin and 4-oxo-isotretinoin under fed states were 18 hours and 38 hours, respectively.
Special Patient PopulationsThe pharmacokinetics of isotretinoin were evaluated after single and multiple doses in 38 pediatric patients (12 to 15 years) and 19 adult patients ( ≥ 18 years) who received isotretinoin for the treatment of severe recalcitrant nodular acne. In both age groups, 4-oxo-isotretinoin was the major metabolite; tretinoin and 4-oxo-tretinoin were also observed. There were no statistically significant differences in the pharmacokinetics of isotretinoin between pediatric and adult patients.
AbsorptionDue to its high lipophilicity, oral absorption of isotretinoin is enhanced when given with a high-fat meal. In a crossover study, 74 healthy adult subjects received a single 80 mg oral dose (2 x 40 mg capsules) of Flexresan (isotretinoin) under fasted and fed conditions. Both peak plasma concentration (Cmax) and the total exposure (AUC) of isotretinoin were more than doubled following a standardized high-fat meal when compared with Flexresan (isotretinoin) given under fasted conditions (see Table 2). The observed elimination half-life was unchanged. This lack of change in half-life suggests that food increases the bioavailability of isotretinoin without altering its disposition. The time to peak concentration (Tmax) was also increased with food and may be related to a longer absorption phase. Therefore, Flexresan (isotretinoin) capsules should always be taken with food (see DOSAGE AND ADMINISTRATION). Clinical studies have shown that there is no difference in the pharmacokinetics of isotretinoin between patients with nodular acne and healthy subjects with normal skin.
Table 2 : Pharmacokinetic Parameters of Isotretinoin Mean (%CV), N=74
| Flexresan 2 x 40 mg Capsules | AUC0-∞ (ng×hr/mL) | Cmax (ng/mL) | Tmax (hr) | t½ (hr) |
| Fed* | 10,004 (22%) | 862 (22%) | 5.3 (77%) | 21 (39%) |
| Fasted | 3,703 (46%) | 301 (63%) | 3.2 (56%) | 21 (30%) |
| *Eating a standardized high-fat meal |
Isotretinoin is more than 99.9% bound to plasma proteins, primarily albumin.
MetabolismFollowing oral administration of isotretinoin, at least three metabolites have been identified in human plasma: 4-oxo-isotretinoin, retinoic acid (tretinoin), and 4-oxo-retinoic acid (4-oxotretinoin). Retinoic acid and 13-cis-retinoic acid are geometric isomers and show reversible interconversion. The administration of one isomer will give rise to the other. Isotretinoin is also irreversibly oxidized to 4-oxo-isotretinoin, which forms its geometric isomer 4-oxo-tretinoin.
After a single 80 mg oral dose of Flexresan (isotretinoin) to 74 healthy adult subjects, concurrent administration of food increased the extent of formation of all metabolites in plasma when compared to the extent of formation under fasted conditions.
All of these metabolites possess retinoid activity that is in some in vitro models more than that of the parent isotretinoin. However, the clinical significance of these models is unknown. After multiple oral dose administration of isotretinoin to adult cystic acne patients ( ≥ 18 years), the exposure of patients to 4-oxo-isotretinoin at steady-state under fasted and fed conditions was approximately 3.4 times higher than that of isotretinoin.
In vitro studies indicate that the primary P450 isoforms involved in isotretinoin metabolism are 2C8, 2C9, 3A4, and 2B6. Isotretinoin and its metabolites are further metabolized into conjugates, which are then excreted in urine and feces.
EliminationFollowing oral administration of an 80 mg dose of 14C-isotretinoin as a liquid suspension, 14Cactivity in blood declined with a half-life of 90 hours. The metabolites of isotretinoin and any conjugates are ultimately excreted in the feces and urine in relatively equal amounts (total of 65% to 83%). After a single 80 mg oral dose of Flexresan (isotretinoin) to 74 healthy adult subjects under fed conditions, the mean ± SD elimination half-lives (t½) of isotretinoin and 4-oxo-isotretinoin were 21.0 ± 8.2 hours and 24.0 ± 5.3 hours, respectively. After both single and multiple doses, the observed accumulation ratios of isotretinoin ranged from 0.90 to 5.43 in patients with cystic acne.
Absorption
The absorption of isotretinoin from the gastro-intestinal tract is variable and dose-linear over the therapeutic range. The absolute bioavailability of isotretinoin has not been determined, since the compound is not available as an intravenous preparation for human use, but extrapolation from dog studies would suggest a fairly low and variable systemic bioavailability. When isotretinoin is taken with food, the bioavailability is doubled relative to fasting conditions.
Distribution
Isotretinoin is extensively bound to plasma proteins, mainly albumin (99.9 %). The volume of distribution of isotretinoin in man has not been determined since isotretinoin is not available as an intravenous preparation for human use. In humans little information is available on the distribution of isotretinoin into tissue. Concentrations of isotretinoin in the epidermis are only half of those in serum. Plasma concentrations of isotretinoin are about 1.7 times those of whole blood due to poor penetration of isotretinoin into red blood cells.
Biotransformation
After oral administration of isotretinoin, three major metabolites have been identified in plasma: 4-oxo-isotretinoin, tretinoin, (all-trans retinoic acid), and 4-oxo-tretinoin. These metabolites have shown biological activity in several in vitro tests. 4-oxo-isotretinoin has been shown in a clinical study to be a significant contributor to the activity of isotretinoin (reduction in sebum excretion rate despite no effect on plasma levels of isotretinoin and tretinoin). Other minor metabolites includes glucuronide conjugates. The major metabolite is 4-oxo-isotretinoin with plasma concentrations at steady state, that are 2.5 times higher than those of the parent compound.
Isotretinoin and tretinoin (all-trans retinoic acid) are reversibly metabolised (interconverted), and the metabolism of tretinoin is therefore linked with that of isotretinoin. It has been estimated that 20-30 % of an isotretinoin dose is metabolised by isomerisation.
Enterohepatic circulation may play a significant role in the pharmacokinetics of isotretinoin in man. In vitro metabolism studies have demonstrated that several CYP enzymes are involved in the metabolism of isotretinoin to 4-oxo-isotretinoin and tretinoin. No single isoform appears to have a predominant role. Isotretinoin and its metabolites do not significantly affect CYP activity.
Elimination
After oral administration of radiolabelled isotretinoin approximately equal fractions of the dose were recovered in urine and faeces. Following oral administration of isotretinoin, the terminal elimination half-life of unchanged drug in patients with acne has a mean value of 19 hours. The terminal elimination half-life of 4-oxo-isotretinoin is longer, with a mean value of 29 hours.
Isotretinoin is a physiological retinoid and endogenous retinoid concentrations are reached within approximately two weeks following the end of isotretinoin therapy.
Hepatic impairment
Since isotretinoin is contraindicated in patients with hepatic impairment, limited information on the kinetics of isotretinoin is available in this patient population.
Renal impairment
Renal failure does not significantly reduce the plasma clearance of isotretinoin or 4-oxo-isotretinoin.
Absorption
The absorption of Flexresan from the gastro-intestinal tract is variable and dose-linear over the therapeutic range. The absolute bioavailability of Flexresan has not been determined, since the compound is not available as an intravenous preparation for human use, but extrapolation from dog studies would suggest a fairly low and variable systemic bioavailability. When Flexresan is taken with food, the bioavailability is doubled relative to fasting conditions.
Distribution
Flexresan is extensively bound to plasma proteins, mainly albumin (99.9%). The volume of distribution of Flexresan in man has not been determined since Flexresan is not available as an intravenous preparation for human use. In humans little information is available on the distribution of Flexresan into tissue. Concentrations of Flexresan in the epidermis are only half of those in serum. Plasma concentrations of Flexresan are about 1.7 times those of whole blood due to poor penetration of Flexresan into red blood cells.
Biotransformation
After oral administration of Flexresan, three major metabolites have been identified in plasma: 4-oxo-Flexresan, tretinoin (all-trans retinoic acid), and 4-oxo-tretinoin. These metabolites have shown biological activity in several in vitro tests. 4-oxo-Flexresan has been shown in a clinical study to be a significant contributor to the activity of Flexresan (reduction in sebum excretion rate despite no effect on plasma levels of Flexresan and tretinoin). Other minor metabolites include glucuronide conjugates. The major metabolite is 4-oxo-Flexresan with plasma concentrations at steady state, that are 2.5 times higher than those of the parent compound.
Flexresan and tretinoin (all-trans retinoic acid) are reversibly metabolised (interconverted), and the metabolism of tretinoin is therefore linked with that of Flexresan. It has been estimated that 20-30% of an Flexresan dose is metabolised by isomerisation.
Enterohepatic circulation may play a significant role in the pharmacokinetics of Flexresan in man. In vitro metabolism studies have demonstrated that several CYP enzymes are involved in the metabolism of Flexresan to 4-oxo-Flexresan and tretinoin. No single isoform appears to have a predominant role. Flexresan and its metabolites do not significantly affect CYP activity.
Elimination
After oral administration of radiolabelled Flexresan approximately equal fractions of the dose were recovered in urine and faeces. Following oral administration of Flexresan, the terminal elimination half-life of unchanged drug in patients with acne has a mean value of 19 hours. The terminal elimination half-life of 4-oxo-Flexresan is longer, with a mean value of 29 hours.
Flexresan is a physiological retinoid and endogenous retinoid concentrations are reached within approximately two weeks following the end of Flexresan therapy.
Hepatic impairment
Since Flexresan is contraindicated in patients with hepatic impairment, limited information on the kinetics of Flexresan is available in this patient population.
Renal impairment
Renal failure does not significantly reduce the plasma clearance of Flexresan or 4-oxo-Flexresan.
Absorption
Following isotretinoin 0.05% gel application to acne patients at a daily dose of 20g (equivalent to 10 mg of isotretinoin) to the face, chest and back for 30 days, plasma concentrations of isotretinoin and tretinoin were not measurable (< 20 ng/mL)
Distribution
Systemic (oral) isotretinoin is more than 99.9% bound to plasma proteins, primarily albumin.
Metabolism
In vivo studies in humans showed that the three major metabolites identified in human plasma following systemic (oral) administration of isotretinoin were 4-oxo-isotretinoin, retinoic acid (tretinoin), and 4-oxo-retinoic acid (4-oxo-tretinoin). In vitro studies indicated that all of these metabolites had retinoid activity.
In vitro studies indicate that the major enzymes responsible for isotretinoin metabolism are cytochrome P450 isoenzymes 2C8, 2C9, 3A4 and 2B6. Isotretinoin and its metabolites are further metabolized into conjugates and excreted in urine and faeces.
Elimination
Following systemic (oral) administration of an 80 mg dose of 14C-isotretinoin, radioactivity in the blood declined with a half-life of 90 hours. The metabolites of isotretinoin and any conjugates are ultimately eliminated in the faeces and urine in similar amounts (total of 65% to 83%).
Included as part of the PRECAUTIONS section.
PRECAUTIONSABSORICA must not be used by female patients who are or may become pregnant. There is an extremely high risk that severe birth defects will result if pregnancy occurs while taking ABSORICA in any amount, even for short periods of time.
ABSORICA 25 mg contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons. Although the overall incidence of FD&C Yellow No.5 (tartrazine) sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity.
Embryofetal Toxicity TeratogenicityMajor congenital malformations, spontaneous abortions, and premature births have been documented following pregnancy exposure to isotretinoin. Females of Reproductive Potential must comply with the pregnancy testing and contraception requirements described in the iPLEDGE program. There are no accurate means of determining whether an exposed fetus has been affected.
No Blood DonationPatients must be informed not to donate blood during isotretinoin therapy and for 1 month following discontinuation of the drug because the blood might be given to a pregnant female patient whose fetus must not be exposed to isotretinoin.
iPLEDGE ProgramBecause of the risk of teratogenicity and to minimize fetal exposure, ABSORICA is available only through a restricted program under a REMS called iPLEDGE. Under the ABSORICA REMS, prescribers, patients, pharmacies, and distributors must enroll and be registered in the program. ABSORICA must not be prescribed, dispensed or otherwise obtained through the internet or any other means outside of the iPLEDGE program. Only FDA-approved isotretinoin products must be distributed, prescribed, dispensed, and used.
Required components of the iPLEDGE Program are:
If a pregnancy does occur during ABSORICA treatment, ABSORICA must be discontinued immediately. The patient should be referred to an obstetrician-gynecologist experienced in reproductive toxicity for further evaluation and counseling. Any suspected fetal exposure during or 1 month after ABSORICA therapy must be reported immediately to the FDA via the MedWatch telephone number 1-800-FDA-1088 and also to the iPLEDGE pregnancy registry at 1-866-495-0654 or via the internet (www.ipledgeprogram.com).
Further information, including a list of qualified pharmacies, is available at www.ipledgeprogram.com or 1-866-495-0654.
Unacceptable Contraception Micro-dosed Progesterone PreparationsMicro-dosed progesterone preparations (“minipills” that do not contain an estrogen) are an inadequate method of contraception during ABSORICA therapy.
Psychiatric DisordersIsotretinoin may cause depression, psychosis and, rarely, suicidal ideation, suicide attempts, suicide, and aggressive and/or violent behaviors. No mechanism of action has been established for these reactions. Prescribers should read the brochure, Recognizing Psychiatric Disorders in Adolescents and Young Adults: A Guide for Prescribers of Isotretinoin. Prescribers should be alert to the warning signs of psychiatric disorders to guide patients to receive the help they need. Therefore, prior to initiation of ABSORICA therapy, patients and family members should be asked about any history of psychiatric disorder, and at each visit during therapy patients should be assessed for symptoms of depression, mood disturbance, psychosis, or aggression to determine if further evaluation may be necessary. Signs and symptoms of depression, as described in the brochure (Recognizing Psychiatric Disorders in Adolescents and Young Adults), include sad mood, hopelessness, feelings of guilt, worthlessness or helplessness, loss of pleasure or interest in activities, fatigue, difficulty concentrating, change in sleep pattern, change in weight or appetite, suicidal thoughts or attempts, restlessness, irritability, acting on dangerous impulses, and persistent physical symptoms unresponsive to treatment. Patients should stop ABSORICA and the patient or a family member should promptly contact their prescriber if the patient develops depression, mood disturbance, psychosis, or aggression, without waiting until the next visit. Discontinuation of ABSORICA therapy may be insufficient; further evaluation may be necessary. While such monitoring may be helpful, it may not detect all patients at risk. Patients may report mental health problems or family history of psychiatric disorders. These reports should be discussed with the patient and/or the patient's family. A referral to a mental health professional may be necessary. The physician should consider whether ABSORICA therapy is appropriate in this setting; for some patients the risks may outweigh the benefits of ABSORICA therapy.
Pseudotumor CerebriIsotretinoin use has been associated with cases of pseudotumor cerebri (benign intracranial hypertension), some of which involved concomitant use of tetracyclines. Concomitant treatment with tetracyclines should therefore be avoided. Early signs and symptoms of pseudotumor cerebri include papilledema, headache, nausea and vomiting, and visual disturbances. Patients with these symptoms should be screened for papilledema and, if present, they should be told to discontinue ABSORICA immediately and be referred to a neurologist for further diagnosis and care.
Serious Skin ReactionsThere have been post-marketing reports of erythema multiforme and severe skin reactions [e.g., Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN)] associated with isotretinoin use. These reactions may be serious and result in death, life-threatening events, hospitalization, or disability. Patients should be monitored closely for severe skin reactions, and discontinuation of ABSORICA should be considered if warranted.
PancreatitisAcute pancreatitis has been reported in isotretinoin-treated patients with either elevated or normal serum triglyceride levels. In rare instances, fatal hemorrhagic pancreatitis has been reported. ABSORICA should be stopped if hypertriglyceridemia cannot be controlled at an acceptable level or if symptoms of pancreatitis occur.
Lipid AbnormalitiesElevations of serum triglycerides in excess of 800 mg/dL have been reported in patients treated with isotretinoin. Marked elevations of serum triglycerides were reported in approximately 25% of patients receiving isotretinoin in clinical trials. In addition, approximately 15% developed a decrease in high-density lipoproteins and about 7% showed an increase in cholesterol levels. In clinical trials, the effects of triglycerides, HDL and cholesterol were reversible upon cessation of isotretinoin therapy. Some patients have been able to reverse triglyceride elevation by reduction in weight, restriction of dietary fat and alcohol, and reduction in the dose while continuing isotretinoin.
Blood lipid determinations should be performed before ABSORICA is given and then at intervals until the lipid response to ABSORICA is established, which usually occurs within 4 weeks. Especially careful consideration must be given to risk/benefit for patients who may be at high risk of triglyceridemia during ABSORICA therapy (patients with diabetes, obesity, increased alcohol intake, lipid metabolism disorder or familial history of lipid metabolism disorder). If ABSORICA therapy is instituted, more frequent checks of serum values for lipids and/or blood sugar are recommended.
The cardiovascular consequences of hypertriglyceridemia associated with isotretinoin are unknown.
Hearing ImpairmentImpaired hearing has been reported in patients taking isotretinoin; in some cases, the hearing impairment has been reported to persist after therapy has been discontinued. Mechanism(s) and causality for this reaction have not been established. Patients who experience tinnitus or hearing impairment should discontinue ABSORICA treatment and be referred for specialized care for further evaluation.
HepatotoxicityClinical hepatitis considered to be possibly or probably related to isotretinoin therapy has been reported. Additionally, mild to moderate elevations of liver enzymes have been observed in approximately 15% of individuals treated during clinical trials with isotretinoin, some of which normalized with dosage reduction or continued administration of the drug. If normalization does not readily occur or if hepatitis is suspected during treatment with ABSORICA, the drug should be discontinued and the etiology further investigated.
Inflammatory Bowel DiseaseIsotretinoin has been associated with inflammatory bowel disease (including regional ileitis) in patients without a prior history of intestinal disorders. In some instances, symptoms have been reported to persist after isotretinoin treatment has been stopped. Patients experiencing abdominal pain, rectal bleeding or severe diarrhea should discontinue ABSORICA immediately.
Skeletal Abnormalities Bone Mineral Density ChangesIsotretinoin may have a negative effect on bone mineral density (BMD) in some patients. In a clinical trial of ABSORICA and a generic product of Accutane® (isotretinoin), 27/306 (8.8%) of adolescents had BMD declines, defined as ≥ 4% lumbar spine or total hip, or ≥ 5% femoral neck, during the 20 week treatment period. Repeat scans conducted within 2-3 months after the post-treatment scan showed no recovery of BMD. Longer term data at 4-11 months showed that 3 out of 7 patients had total hip and femoral neck BMD below pre-treatment baseline, and 2 others did not show the increase in BMD above baseline expected in this adolescent population. Therefore, physicians should use caution when prescribing ABSORICA to patients with a history of childhood osteoporosis conditions, osteomalacia, or other disorders of bone metabolism. This would include patients diagnosed with anorexia nervosa and those who are on chronic drug therapy that causes drug-induced osteoporosis/osteomalacia and/or affects vitamin D metabolism, such as systemic corticosteroids and any anticonvulsant.
Musculoskeletal AbnormalitiesApproximately 16% of patients treated with isotretinoin in a clinical trial developed musculoskeletal symptoms (including arthralgia) during treatment. In general, these symptoms were mild to moderate, but occasionally required discontinuation of the drug.
In a trial of pediatric patients treated with isotretinoin, approximately 29% (104/358) developed back pain. Back pain was severe in 13.5% (14/104) of the cases and occurred at a higher frequency in female patients than male patients. Arthralgias were experienced in 22% (79/358) of pediatric patients. Arthralgias were severe in 7.6% (6/79) of patients. Appropriate evaluation of the musculoskeletal system should be done in patients who present with these symptoms during or after a course of ABSORICA. Consideration should be given to discontinuation of ABSORICA if any significant abnormality is found.
There have been spontaneous reports of osteoporosis, osteopenia, bone fractures and/or delayed healing of bone fractures in patients while on therapy with isotretinoin or following cessation of therapy with isotretinoin. While causality to isotretinoin has not been established, an effect cannot be ruled out.
Patients may be at an increased risk when participating in sports with repetitive impact where the risks of spondylolisthesis with and without pars fractures and hip growth plate injures in early and late adolescence are known.
Effects of multiple courses of isotretinoin on the developing musculoskeletal system are unknown. There is some evidence that long-term, high-dose, or multiple courses of therapy with isotretinoin have more of an effect than a single course of therapy on the musculoskeletal system.
Longer term effects have not been studied. It is important that ABSORICA be given at the recommended doses for no longer than the recommended duration.
HyperostosisA high prevalence of skeletal hyperostosis was noted in clinical trials for disorders of keratinization with a mean dose of 2.24 mg/kg/day of isotretinoin. Additionally, skeletal hyperostosis was noted in 6 of 8 patients in a prospective trial of disorders of keratinization. Minimal skeletal hyperostosis and calcification of ligaments and tendons have also been observed by x-ray in prospective trials of nodular acne patients treated with a single course of therapy at recommended doses. The skeletal effects of multiple isotretinoin treatment courses for acne are unknown.
In a clinical trial of 217 pediatric patients (12 to 17 years) with severe recalcitrant nodular acne, hyperostosis was not observed after 16 to 20 weeks of treatment with approximately 1 mg/kg/day of isotretinoin given in two divided doses. Hyperostosis may require a longer time frame to appear. The clinical course and significance remain unknown.
Premature Epiphyseal ClosureThere are spontaneous literature reports of premature epiphyseal closure in acne patients receiving recommended doses of isotretinoin. The effect of multiple courses of isotretinoin on epiphyseal closure is unknown.
In a 20-week clinical trial that included 289 adolescents on ABSORICA or a generic product of Accutane® (isotretinoin) who had hand radiographs taken to assess bone age, a total of 9 (3.11%) patients had bone age changes that were clinically significant and for which a drug-related effect cannot be excluded.
Ocular AbnormalitiesVisual problems should be carefully monitored. All ABSORICA patients experiencing visual difficulties should discontinue ABSORICA treatment and have an ophthalmological examination.
Corneal OpacitiesCorneal opacities have occurred in patients receiving isotretinoin for acne and more frequently when higher drug dosages were used in patients with disorders of keratinization. The corneal opacities that have been observed in clinical trial patients treated with isotretinoin have either completely resolved or were resolving at follow-up 6 to 7 weeks after discontinuation of the drug.
Decreased Night VisionDecreased night vision has been reported during isotretinoin therapy and in some instances the event has persisted after therapy was discontinued. Because the onset in some patients was sudden, patients should be advised of this potential problem and warned to be cautious when driving or operating any vehicle at night.
Dry EyeDry eye has been reported in subjects during isotretinoin therapy. Patients who wear contact lenses may have trouble wearing them while on ABSORICA treatment and afterwards.
HypersensitivityAnaphylactic reactions and other allergic reactions have been reported in isotretinoin-treated patients. Cutaneous allergic reactions and serious cases of allergic vasculitis, often with purpura (bruises and red patches) of the extremities and extracutaneous involvement (including renal) have been reported. Severe allergic reaction necessitates discontinuation of therapy and appropriate medical management.
Laboratory Monitoring For Adverse Reactions Lipids TestPretreatment and follow-up blood lipids should be obtained under fasting conditions. After consumption of alcohol, at least 36 hours should elapse before these determinations are made. It is recommended that these tests be performed at weekly or biweekly intervals until the lipid response to ABSORICA is established. The incidence of hypertriglyceridemia is 1 patient in 4 on isotretinoin.
Liver Function TestSince elevations of liver enzymes have been observed during clinical trials, and hepatitis has been reported in patients on isotretinoin, pretreatment and follow-up liver function tests should be performed at weekly or biweekly intervals until the response to ABSORICA has been established.
GlucoseSome patients receiving isotretinoin have experienced problems in the control of their blood sugar. In addition, new cases of diabetes have been diagnosed during isotretinoin therapy, although no causal relationship has been established.
CPKSome patients undergoing vigorous physical activity while on isotretinoin therapy have experienced elevated CPK levels; however, the clinical significance is unknown. There have been rare postmarketing reports of rhabdomyolysis, some associated with strenuous physical activity. In an isotretinoin clinical trial of 924 patients, marked elevations in CPK ( ≥ 350 U/L) were observed in approximately 24% of patients. In another clinical trial of 217 pediatric patients (12 – 17 years) elevations in CPK were observed in 12% of patients, including those undergoing strenuous physical activity in association with reported musculoskeletal adverse events such as back pain, arthralgia, limb injury, or muscle sprain. In these patients, approximately half of the CPK elevations returned to normal within 2 weeks and half returned to normal within 4 weeks. No cases of rhabdomyolysis were reported in this clinical trial.
Patient Counseling InformationSee FDA-Approved Patient Labeling (Medication Guide)
Advise the patient that ABSORICA is only available through a restricted program called iPLEDGE.
In male and female Fischer 344 rats given oral isotretinoin at dosages of 8 or 32 mg/kg/day (1.3 to 5.3 times the recommended clinical dose of 1 mg/kg/day, respectively, after normalization for total body surface area) for greater than 18 months, there was a dose-related increased incidence of pheochromocytoma relative to controls. The incidence of adrenal medullary hyperplasia was also increased at the higher dosage in both sexes. The relatively high level of spontaneous pheochromocytomas occurring in the male Fischer 344 rat makes it an equivocal model for study of this tumor; therefore, the relevance of this tumor to the human population is uncertain.
The Ames test was conducted with isotretinoin in two laboratories. The results of the tests in one laboratory were negative while in the second laboratory a weakly positive response (less than 1.6 x background) was noted in S. typhimurium TA100 when the assay was conducted with metabolic activation. No dose response effect was seen and all other strains were negative. Additionally, other tests designed to assess genotoxicity (Chinese hamster cell assay, mouse micronucleus test, S. cerevisiae D7 assay, in vitr
WARNINGS Psychiatric DisordersFlexresan (isotretinoin) may cause depression, psychosis and, rarely, suicidal ideation, suicide attempts, suicide, and aggressive and/or violent behaviors. No mechanism of action has been established for these events (see ADVERSE REACTIONS: Psychiatric). Prescribers should read the brochure, Recognizing Psychiatric Disorders in Adolescents and Young Adults: A Guide for Prescribers of Isotretinoin. Prescribers should be alert to the warning signs of psychiatric disorders to guide patients to receive the help they need. Therefore, prior to initiation of Flexresan (isotretinoin) therapy, patients and family members should be asked about any history of psychiatric disorder, and at each visit during therapy patients should be assessed for symptoms of depression, mood disturbance, psychosis, or aggression to determine if further evaluation may be necessary. Signs and symptoms of depression, as described in the brochure (“Recognizing Psychiatric Disorders in Adolescents and Young Adults”), include sad mood, hopelessness, feelings of guilt, worthlessness or helplessness, loss of pleasure or interest in activities, fatigue, difficulty concentrating, change in sleep pattern, change in weight or appetite, suicidal thoughts or attempts, restlessness, irritability, acting on dangerous impulses, and persistent physical symptoms unresponsive to treatment. Patients should stop Flexresan (isotretinoin) and the patient or a family member should promptly contact their prescriber if the patient develops depression, mood disturbance, psychosis, or aggression, without waiting until the next visit. Discontinuation of Flexresan (isotretinoin) therapy may be insufficient; further evaluation may be necessary. While such monitoring may be helpful, it may not detect all patients at risk. Patients may report mental health problems or family history of psychiatric disorders. These reports should be discussed with the patient and/or the patient's family. A referral to a mental health professional may be necessary. The physician should consider whether Flexresan (isotretinoin) therapy is appropriate in this setting; for some patients the risks may outweigh the benefits of Flexresan (isotretinoin) therapy.
Pseudotumor CerebriFlexresan (isotretinoin) use has been associated with a number of cases of pseudotumor cerebri (benign intracranial hypertension), some of which involved concomitant use of tetracyclines. Concomitant treatment with tetracyclines should therefore be avoided. Early signs and symptoms of pseudotumor cerebri include papilledema, headache, nausea and vomiting, and visual disturbances. Patients with these symptoms should be screened for papilledema and, if present, they should be told to discontinue Flexresan (isotretinoin) immediately and be referred to a neurologist for further diagnosis and care (see ADVERSE REACTIONS: Neurological).
Serious Skin ReactionsThere have been post-marketing reports of erythema multiforme and severe skin reactions [eg, Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN)] associated with isotretinoin use. These events may be serious and result in death, life-threatening events, hospitalization, or disability. Patients should be monitored closely for severe skin reactions, and discontinuation of Flexresan (isotretinoin) should be considered if warranted.
PancreatitisAcute pancreatitis has been reported in patients with either elevated or normal serum triglyceride levels. In rare instances, fatal hemorrhagic pancreatitis has been reported. Flexresan (isotretinoin) should be stopped if hypertriglyceridemia cannot be controlled at an acceptable level or if symptoms of pancreatitis occur.
LipidsElevations of serum triglycerides in excess of 800 mg/dL have been reported in patients treated with Flexresan (isotretinoin). Marked elevations of serum triglycerides were reported in approximately 25% of patients receiving Flexresan (isotretinoin) in clinical trials. In addition, approximately 15% developed a decrease in high-density lipoproteins and about 7% showed an increase in cholesterol levels. In clinical trials, the effects on triglycerides, HDL, and cholesterol were reversible upon cessation of Flexresan (isotretinoin) therapy. Some patients have been able to reverse triglyceride elevation by reduction in weight, restriction of dietary fat and alcohol, and reduction in dose while continuing Flexresan (isotretinoin).5
Blood lipid determinations should be performed before Flexresan (isotretinoin) is given and then at intervals until the lipid response to Flexresan (isotretinoin) is established, which usually occurs within 4 weeks. Especially careful consideration must be given to risk/benefit for patients who may be at high risk during Flexresan (isotretinoin) therapy (patients with diabetes, obesity, increased alcohol intake, lipid metabolism disorder or familial history of lipid metabolism disorder). If Flexresan (isotretinoin) therapy is instituted, more frequent checks of serum values for lipids and/or blood sugar are recommended (see PRECAUTIONS: Laboratory Tests).
The cardiovascular consequences of hypertriglyceridemia associated with Flexresan (isotretinoin) are unknown. Animal Studies: In rats given 8 or 32 mg/kg/day of isotretinoin (1.3 to 5.3 times the recommended clinical dose of 1.0 mg/kg/day after normalization for total body surface area) for 18 months or longer, the incidences of focal calcification, fibrosis and inflammation of the myocardium, calcification of coronary, pulmonary and mesenteric arteries, and metastatic calcification of the gastric mucosa were greater than in control rats of similar age. Focal endocardial and myocardial calcifications associated with calcification of the coronary arteries were observed in two dogs after approximately 6 to 7 months of treatment with isotretinoin at a dosage of 60 to 120 mg/kg/day (30 to 60 times the recommended clinical dose of 1.0 mg/kg/day, respectively, after normalization for total body surface area).
Hearing ImpairmentImpaired hearing has been reported in patients taking Flexresan (isotretinoin) ; in some cases, the hearing impairment has been reported to persist after therapy has been discontinued. Mechanism(s) and causality for this event have not been established. Patients who experience tinnitus or hearing impairment should discontinue Flexresan (isotretinoin) treatment and be referred for specialized care for further evaluation (see ADVERSE REACTIONS: Special Senses).
HepatotoxicityClinical hepatitis considered to be possibly or probably related to Flexresan (isotretinoin) therapy has been reported. Additionally, mild to moderate elevations of liver enzymes have been observed in approximately 15% of individuals treated during clinical trials, some of which normalized with dosage reduction or continued administration of the drug. If normalization does not readily occur or if hepatitis is suspected during treatment with Flexresan (isotretinoin) , the drug should be discontinued and the etiology further investigated.
Inflammatory Bowel DiseaseFlexresan (isotretinoin) has been associated with inflammatory bowel disease (including regional ileitis) in patients without a prior history of intestinal disorders. In some instances, symptoms have been reported to persist after Flexresan (isotretinoin) treatment has been stopped. Patients experiencing abdominal pain, rectal bleeding or severe diarrhea should discontinue Flexresan immediately (see ADVERSE REACTIONS: Gastrointestinal).
Skeletal Bone Mineral DensityEffects of multiple courses of Flexresan (isotretinoin) on the developing musculoskeletal system are unknown. There is some evidence that long-term, high-dose, or multiple courses of therapy with isotretinoin have more of an effect than a single course of therapy on the musculoskeletal system. In an open-label clinical trial (N=217) of a single course of therapy with Flexresan (isotretinoin) for severe recalcitrant nodular acne, bone density measurements at several skeletal sites were not significantly decreased (lumbar spine change > -4% and total hip change > -5%) or were increased in the majority of patients. One patient had a decrease in lumbar spine bone mineral density > 4% based on unadjusted data. Sixteen (7.9%) patients had decreases in lumbar spine bone mineral density > 4%, and all the other patients (92%) did not have significant decreases or had increases (adjusted for body mass index). Nine patients (4.5%) had a decrease in total hip bone mineral density > 5% based on unadjusted data. Twenty-one (10.6%) patients had decreases in total hip bone mineral density > 5%, and all the other patients (89%) did not have significant decreases or had increases (adjusted for body mass index). Follow-up studies performed in 8 of the patients with decreased bone mineral density for up to 11 months thereafter demonstrated increasing bone density in 5 patients at the lumbar spine, while the other 3 patients had lumbar spine bone density measurements below baseline values. Total hip bone mineral densities remained below baseline (range –1.6% to –7.6%) in 5 of 8 patients (62.5%).
In a separate open-label extension study of 10 patients, ages 13-18 years, who started a second course of Flexresan (isotretinoin) 4 months after the first course, two patients showed a decrease in mean lumbar spine bone mineral density up to 3.25% (see PRECAUTIONS: Pediatric Use).
Spontaneous reports of osteoporosis, osteopenia, bone fractures, and delayed healing of bone fractures have been seen in the Flexresan (isotretinoin) population. While causality to Flexresan (isotretinoin) has not been established, an effect cannot be ruled out. Longer term effects have not been studied. It is important that Flexresan (isotretinoin) be given at the recommended doses for no longer than the recommended duration.
HyperostosisA high prevalence of skeletal hyperostosis was noted in clinical trials for disorders of keratinization with a mean dose of 2.24 mg/kg/day. Additionally, skeletal hyperostosis was noted in 6 of 8 patients in a prospective study of disorders of keratinization.6 Minimal skeletal hyperostosis and calcification of ligaments and tendons have also been observed by x-ray in prospective studies of nodular acne patients treated with a single course of therapy at recommended doses. The skeletal effects of multiple Flexresan (isotretinoin) treatment courses for acne are unknown.
In a clinical study of 217 pediatric patients (12 to 17 years) with severe recalcitrant nodular acne, hyperostosis was not observed after 16 to 20 weeks of treatment with approximately 1 mg/kg/day of Flexresan (isotretinoin) given in two divided doses. Hyperostosis may require a longer time frame to appear. The clinical course and significance remain unknown.
Premature Epiphyseal ClosureThere are spontaneous reports of premature epiphyseal closure in acne patients receiving recommended doses of Flexresan (isotretinoin). The effect of multiple courses of Flexresan (isotretinoin) on epiphyseal closure is unknown.
Vision ImpairmentVisual problems should be carefully monitored. All Flexresan (isotretinoin) patients experiencing visual difficulties should discontinue Flexresan (isotretinoin) treatment and have an ophthalmological examination (see ADVERSE REACTIONS: Special Senses).
Corneal OpacitiesCorneal opacities have occurred in patients receiving Flexresan (isotretinoin) for acne and more frequently when higher drug dosages were used in patients with disorders of keratinization. The corneal opacities that have been observed in clinical trial patients treated with Flexresan (isotretinoin) have either completely resolved or were resolving at follow-up 6 to 7 weeks after discontinuation of the drug (see ADVERSE REACTIONS: Special Senses).
Decreased Night VisionDecreased night vision has been reported during Flexresan (isotretinoin) therapy and in some instances the event has persisted after therapy was discontinued. Because the onset in some patients was sudden, patients should be advised of this potential problem and warned to be cautious when driving or operating any vehicle at night.
PRECAUTIONSFlexresan (isotretinoin) must only be prescribed by prescribers who are registered and activated with the iPLEDGE program. Flexresan (isotretinoin) must only be dispensed by a pharmacy registered and activated with iPLEDGE, and must only be dispensed to patients who are registered and meet all the requirements of iPLEDGE. Registered and activated pharmacies must receive Flexresan (isotretinoin) only from wholesalers registered with iPLEDGE.
iPLEDGE program requirements for wholesalers, prescribers, and pharmacists are described below:
WholesalersFor the purpose of the iPLEDGE program, the term wholesaler refers to wholesaler, distributor, and/or chain pharmacy distributor. To distribute Flexresan (isotretinoin) , wholesalers must be registered with iPLEDGE, and agree to meet all iPLEDGE requirements for wholesale distribution of isotretinoin products. Wholesalers must register with iPLEDGE by signing and returning the iPLEDGE wholesaler agreement that affirms they will comply with all iPLEDGE requirements for distribution of isotretinoin. These include:
To prescribe isotretinoin, the prescriber must be registered and activated with the pregnancy risk management program iPLEDGE. Prescribers can register by signing and returning the completed registration form. Prescribers can only activate their registration by affirming that they meet requirements and will comply with all iPLEDGE requirements by attesting to the following points:
To prescribe isotretinoin, the prescriber must access the iPLEDGE system via the internet (www.ipledgeprogram.com) or telephone (1-866-495-0654) to:
Isotretinoin must only be prescribed to female patients who are known not to be pregnant as confirmed by a negative CLIA-certified laboratory conducted pregnancy test.
Isotretinoin must only be dispensed by a pharmacy registered and activated with the pregnancy risk management program iPLEDGE and only when the registered patient meets all the requirements of the iPLEDGE program. Meeting the requirements for a female patient of childbearing potential signifies that she:
Effective forms of contraception include both primary and secondary forms of contraception:
| Primary forms | Secondary forms |
| Barrier: |
| |
| Other: | |
|
Any birth control method can fail. There have been reports of pregnancy from female patients who have used oral contraceptives, as well as transdermal patch/injectable/implantable/vaginal ring hormonal birth control products; these pregnancies occurred while these patients were taking Flexresan (isotretinoin). These reports are more frequent for female patients who use only a single method of contraception. Therefore, it is critically important that female patients of childbearing potential use 2 effective forms of contraception simultaneously. Patients must receive written warnings about the rates of possible contraception failure (included in patient education kits).
Using two forms of contraception simultaneously substantially reduces the chances that a female will become pregnant over the risk of pregnancy with either form alone. A drug interaction that decreases effectiveness of hormonal contraceptives has not been entirely ruled out for Flexresan (see PRECAUTIONS: DRUG INTERACTIONS). Although hormonal contraceptives are highly effective, prescribers are advised to consult the package insert of any medication administered concomitantly with hormonal contraceptives, since some medications may decrease the effectiveness of these birth control products.
Patients should be prospectively cautioned not to self-medicate with the herbal supplement St. John's Wort because a possible interaction has been suggested with hormonal contraceptives based on reports of breakthrough bleeding on oral contraceptives shortly after starting St. John's Wort. Pregnancies have been reported by users of combined hormonal contraceptives who also used some form of St. John's Wort.
If a pregnancy does occur during isotretinoin treatment, isotretinoin must be discontinued immediately. The patient should be referred to an Obstetrician-Gynecologist experienced in reproductive toxicity for further evaluation and counseling. Any suspected fetal exposure during or 1 month after isotretinoin therapy must be reported immediately to the FDA via the MedWatch number 1-800-FDA-1088 and also to the iPLEDGE pregnancy registry at 1-866-495-0654 or via the internet (www.ipledgeprogram.com).
All PatientsIsotretinoin is contraindicated in female patients who are pregnant. To receive isotretinoin all patients must meet all of the following conditions:
Isotretinoin is contraindicated in female patients who are pregnant. In addition to the requirements for all patients described above, female patients of childbearing potential must meet the following conditions:
To dispense isotretinoin, pharmacies must be registered and activated with the pregnancy risk management program iPLEDGE.
The Responsible Site Pharmacist must register the pharmacy by signing and returning the completed registration form. After registration, the Responsible Site Pharmacist can only activate the pharmacy registration by affirming that they meet requirements and will comply with all iPLEDGE requirements by attesting to the following points:
To dispense isotretinoin, the pharmacist must:
Flexresan (isotretinoin) must only be dispensed:
An Flexresan Medication Guide must be given to the patient each time Flexresan (isotretinoin) is dispensed, as required by law. This Flexresan Medication Guide is an important part of the risk management program for the patients.
Flexresan (isotretinoin) must not be prescribed, dispensed or otherwise obtained through the internet or any other means outside of the iPLEDGE program. Only FDA-approved Flexresan (isotretinoin) products must be distributed, prescribed, dispensed, and used. Patients must fill Flexresan (isotretinoin) prescriptions only at US licensed pharmacies.
A description of the iPLEDGE program educational materials available with iPLEDGE is provided below. The main goal of these educational materials is to explain the iPLEDGE program requirements and to reinforce the educational messages.
Pregnancy Prevention Programme
This medicinal product is TERATOGENIC
Isotretinoin is contraindicated in women of childbearing potential unless all of the following conditions of the Pregnancy Prevention Programme are met:
- She has severe acne (such as nodular or conglobate acne or acne at risk of permanent scarring) resistant to adequate courses of standard therapy with systemic anti-bacterials and topical therapy.
- She understands the teratogenic risk.
- She understands the need for rigorous follow-up, on a monthly basis.
- She understands and accepts the need for effective contraception, without interruption, 1 month before starting treatment, throughout the duration of treatment and 1 month after the end of treatment. At least one and preferably two complementary forms of contraception including a barrier method should be used.
- Even if she has amenorrhea she must follow all of the advice on effective contraception.
- She should be capable of complying with effective contraceptive measures.
- She is informed and understands the potential consequences of pregnancy and the need to rapidly consult if there is a risk of pregnancy.
- She understands the need and accepts to undergo pregnancy testing before, during and 5 weeks after the end of treatment.
- She has acknowledged that she has understood the hazards and necessary precautions associated with the use of isotretinoin.
These conditions also concern women who are not currently sexually active unless the prescriber considers that there are compelling reasons to indicate that there is no risk of pregnancy.
The prescriber must ensure that:
- The patient complies with the conditions for pregnancy prevention as listed above, including confirmation that she has an adequate level of understanding.
- The patient has acknowledged the aforementioned conditions.
- The patient has used at least one and preferably two methods of effective contraception including a barrier method for at least 1 month prior to starting treatment and is continuing to use effective contraception throughout the treatment period and for at least 1 month after cessation of treatment.
- Negative pregnancy test results have been obtained before, during and 5 weeks after the end of treatment. The dates and results of pregnancy tests should be documented.
Contraception
Female patients must be provided with comprehensive information on pregnancy prevention and should be referred for contraceptive advice if they are not using effective contraception.
As a minimum requirement, female patients at potential risk of pregnancy must use at least one effective method of contraception. Preferably the patient should use two complementary forms of contraception including a barrier method. Contraception should be continued for at least 1 month after stopping treatment with isotretinoin, even in patients with amenorrhea.
Pregnancy testing
According to local practice, medically supervised pregnancy tests with a minimum sensitivity of 25 mIU/mL are recommended to be performed in the first 3 days of the menstrual cycle, as follows.
Prior to starting therapy:
In order to exclude the possibility of pregnancy prior to starting contraception, it is recommended that an initial medically supervised pregnancy test should be performed and its date and result recorded. In patients without regular menses, the timing of this pregnancy test should reflect the sexual activity of the patient and should be undertaken approximately 3 weeks after the patient last had unprotected sexual intercourse. The prescriber should educate the patient about contraception.
A medically supervised pregnancy test should also be performed during the consultation when isotretinoin is prescribed or in the 3 days prior to the visit to the prescriber, and should have been delayed until the patient had been using effective contraception for at least 1 month. This test should ensure the patient is not pregnant when she starts treatment with isotretinoin.
Follow-up visits
Follow-up visits should be arranged at 28 day intervals. The need for repeated medically supervised pregnancy tests every month should be determined according to local practice including consideration of the patient's sexual activity and recent menstrual history (abnormal menses, missed periods or amenorrhea). Where indicated, follow-up pregnancy tests should be performed on the day of the prescribing visit or in the 3 days prior to the visit to the prescriber.
End of treatment
Five weeks after stopping treatment, women should undergo a final pregnancy test to exclude pregnancy.
Prescribing and dispensing restrictions
Prescriptions of isotretinoin for women of childbearing potential should be limited to 30 days of treatment and continuation of treatment requires a new prescription. Ideally, pregnancy testing, issuing a prescription and dispensing of isotretinoin should occur on the same day. Dispensing of isotretinoin should occur within a maximum of 7 days of the prescription.
Male patients:
The available data suggest that the level of maternal exposure from the semen of the patients receiving isotretinoin, is not of a sufficient magnitude to be associated with the teratogenic effects of isotretinoin.
Male patients should be reminded that they must not share their medication with anyone, particularly not females.
Additional precautions
Patients should be instructed never to give this medicinal product to another person, and to return any unused capsules to their pharmacist at the end of treatment.
Patients should not donate blood during therapy and for 1 month following discontinuation of isotretinoin because of the potential risk to the foetus of a pregnant transfusion recipient.
Educational material
In order to assist prescribers, pharmacists and patients in avoiding foetal exposure to isotretinoin the Marketing Authorisation Holder will provide educational material to reinforce the warnings about the teratogenicity of isotretinoin, to provide advice on contraception before therapy is started and to provide guidance on the need for pregnancy testing.
Full patient information about the teratogenic risk and the strict pregnancy prevention measures as specified in the Pregnancy Prevention Programme should be given by the physician to all patients, both male and female.
Psychiatric disorders
Depression, depression aggravated, anxiety, aggressive tendencies, mood alterations, psychotic symptoms, and very rarely, suicidal ideation, suicide attempts and suicide have been reported in patients treated with isotretinoin. Particular care needs to be taken in patients with a history of depression and all patients should be monitored for signs of depression and referred for appropriate treatment if necessary. However, discontinuation of isotretinoin may be insufficient to alleviate symptoms and therefore further psychiatric or psychological evaluation may be necessary.
Skin and subcutaneous tissues disorders
Acute exacerbation of acne is occasionally seen during the initial period but this subsides with continued treatment, usually within 7-10 days, and usually does not require dose adjustment.
Exposure to intense sunlight or to UV rays should be avoided. Where necessary a sun-protection product with a high protection factor of at least SPF 15 should be used.
Aggressive chemical dermabrasion and cutaneous laser treatment should be avoided in patients on isotretinoin for a period of 5-6 months after the end of the treatment because of the risk of hypertrophic scarring in atypical areas and more rarely post inflammatory hyper or hypopigmentation in treated areas. Wax depilation should be avoided in patients on isotretinoin for at least a period of 6 months after treatment because of the risk of epidermal stripping.
Concurrent administration of isotretinoin with topical keratolytic or exfoliative anti-acne agents should be avoided as local irritation may increase.
Patients should be advised to use a skin moisturising ointment or cream and a lip balm from the start of treatment as isotretinoin is likely to cause dryness of the skin and lips.
There have been post-marketing reports of severe skin reactions (e.g. erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)) associated with isotretinoin use. As these events may be difficult to distinguish from other skin reactions that may occur , patients should be advised of the signs and symptoms and monitored closely for severe skin reactions. If a severe skin reaction is suspected, isotretinoin treatment should be discontinued.
Allergic reactions
Anaphylactic reactions have been rarely reported, in some cases after previous topical exposure to retinoids. Allergic cutaneous reactions are reported infrequently. Serious cases of allergic vasculitis, often with purpura (bruises and red patches) of the extremities and extracutaneous involvement have been reported. Severe allergic reactions necessitate interruption of therapy and careful monitoring.
Eye disorders
Dry eyes, corneal opacities, decreased night vision and keratitis usually resolve after discontinuation of therapy. Dry eyes can be helped by the application of a lubricating eye ointment or by the application of tear replacement therapy. Intolerance to contact lenses may occur which may necessitate the patient to wear glasses during treatment.
Decreased night vision has also been reported and the onset in some patients was sudden. Patients experiencing visual difficulties should be referred for an expert ophthalmological opinion. Withdrawal of isotretinoin may be necessary.
Musculo-skeletal and connective tissue disorders
Myalgia, arthralgia and increased serum creatine phosphokinase values have been reported in patients receiving isotretinoin, particularly in those undertaking vigorous physical activity. In some cases, this may progress to potentially life threatening rhabdomyolysis.
Bone changes including premature epiphyseal closure, hyperostosis, and calcification of tendons and ligaments have occurred after several years of administration at very high doses for treating disorders of keratinisation. The dose levels, duration of treatment and total cumulative dose in these patients generally far exceeded those recommended for the treatment of acne.
Benign intracranial hypertension
Cases of benign intracranial hypertension have been reported, some of which involved concomitant use of tetracyclines. Signs and symptoms of benign intracranial hypertension include headache, nausea and vomiting, visual disturbances and papilloedema. Patients who develop benign intracranial hypertension should discontinue isotretinoin immediately.
Hepatobiliary disorders
Liver enzymes should be checked before treatment, 1 month after the start of treatment, and subsequently at 3 monthly intervals unless more frequent monitoring is clinically indicated. Transient and reversible increases in liver transaminases have been reported. In many cases these changes have been within the normal range and values have returned to baseline levels during treatment. However, in the event of persistent clinically relevant elevation of transaminase levels, reduction of the dose or discontinuation of treatment should be considered.
Renal insufficiency
Renal insufficiency and renal failure do not affect the pharmacokinetics of isotretinoin. Therefore, isotretinoin can be given to patients with renal insufficiency. However, it is recommended that patients are started on a low dose and titrated up to the maximum tolerated dose.
Lipid Metabolism
Serum lipids (fasting values) should be checked before treatment, 1 month after the start of treatment, and subsequently at 3 monthly intervals unless more frequent monitoring is clinically indicated. Elevated serum lipid values usually return to normal on reduction of the dose or discontinuation of treatment and may also respond to dietary measures.
Isotretinoin has been associated with an increase in plasma triglyceride levels. Isotretinoin should be discontinued if hypertriglyceridaemia cannot be controlled at an acceptable level or if symptoms of pancreatitis occur. Levels in excess of 800 mg/dL or 9 mmol/L are sometimes associated with acute pancreatitis, which may be fatal.
Gastrointestinal disorders
Isotretinoin has been associated with inflammatory bowel disease (including regional ileitis) in patients without a prior history of intestinal disorders. Patients experiencing severe (hemorrhagic) diarrhoea should discontinue isotretinoin immediately.
Fructose intolerance
Flexresan contains sorbitol. Patients with rare hereditary problems of fructose intolerance should not take this medicine.
High Risk Patients
In patients with diabetes, obesity, alcoholism or a lipid metabolism disorder undergoing treatment with isotretinoin, more frequent checks of serum values for lipids and/or blood glucose may be necessary. Elevated fasting blood sugars have been reported, and new cases of diabetes have been diagnosed during isotretinoin therapy.
Pregnancy Prevention Programme
This medicinal product is TERATOGENIC
Flexresan is contraindicated in women of childbearing potential unless all of the following conditions of the Pregnancy Prevention Programme are met:
She has severe acne (such as nodular or conglobate acne or acne at risk of permanent scarring) resistant to adequate courses of standard therapy with systemic antibacterials and topical therapy.
She understands the teratogenic risk.
She understands the need for rigorous follow-up, on a monthly basis.
She understands and accepts the need for effective contraception, without interruption, 1 month before starting treatment, throughout the duration of treatment and 1 month after the end of treatment. At least one and preferably two complementary forms of contraception including a barrier method should be used.
Even if she has amenorrhoea she must follow all of the advice on effective contraception.
She should be capable of complying with effective contraceptive measures.
She is informed and understands the potential consequences of pregnancy and the need to rapidly consult if there is a risk of pregnancy.
She understands the need and accepts to undergo pregnancy testing before, during and 5 weeks after the end of treatment.
She has acknowledged that she has understood the hazards and necessary precautions associated with the use of Flexresan.
These conditions also concern women who are not currently sexually active unless the prescriber considers that there are compelling reasons to indicate that there is no risk of pregnancy.
The prescriber must ensure that:
The patient complies with the conditions for pregnancy prevention as listed above, including confirmation that she has an adequate level of understanding.
The patient has acknowledged the aforementioned conditions.
The patient has used at least one and preferably two methods of effective contraception including a barrier method for at least 1 month prior to starting treatment and is continuing to use effective contraception throughout the treatment period and for at least 1 month after cessation of treatment.
Negative pregnancy test results have been obtained before, during and 5 weeks after the end of treatment. The dates and results of pregnancy tests should be documented.
Contraception
Female patients must be provided with comprehensive information on pregnancy prevention and should be referred for contraceptive advice if they are not using effective contraception.
As a minimum requirement, female patients at potential risk of pregnancy must use at least one effective method of contraception. Preferably the patient should use two complementary forms of contraception including a barrier method. Contraception should be continued for at least 1 month after stopping treatment with Flexresan, even in patients with amenorrhoea.
Pregnancy testing
According to local practice medically supervised pregnancy tests with a minimum sensitivity of 25 mIU/mL are recommended to be performed in the first 3 days of the menstrual cycle, as follows.
Prior to starting therapy:
In order to exclude the possibility of pregnancy prior to starting contraception, it is recommended that an initial medically supervised pregnancy test should be performed and its date and result recorded. In patients without regular menses, the timing of this pregnancy test should reflect the sexual activity of the patient and should be undertaken approximately 3 weeks after the patient last had unprotected sexual intercourse. The prescriber should educate the patient about contraception.
A medically supervised pregnancy test should also be performed during the consultation when Flexresan is prescribed or in the 3 days prior to the visit to the prescriber, and should have been delayed until the patient had been using effective contraception for at least 1 month. This test should ensure the patient is not pregnant when she starts treatment with Flexresan.
Follow-up visits
Follow-up visits should be arranged at 28 day intervals. The need for repeated medically supervised pregnancy tests every month should be determined according to local practice including consideration of the patient's sexual activity and recent menstrual history (abnormal menses, missed periods or amenorrhoea). Where indicated, follow-up pregnancy tests should be performed on the day of the prescribing visit or in the 3 days prior to the visit to the prescriber.
End of treatment
Five weeks after stopping treatment, women should undergo a final pregnancy test to exclude pregnancy.
Prescribing and dispensing restrictions
Prescriptions of Flexresan for women of childbearing potential should be limited to 30 days of treatment and continuation of treatment requires a new prescription. Ideally, pregnancy testing, issuing a prescription and dispensing of Flexresan should occur on the same day. Dispensing of Flexresan should occur within a maximum of 7 days of the prescription.
Male patients
The available data suggest that the level of maternal exposure from the semen of the patients receiving Flexresan, is not of a sufficient magnitude to be associated with the teratogenic effects of Flexresan.
Male patients should be reminded that they must not share their medication with anyone, particularly not females.
Additional precautions
Patients should be instructed never to give this medicinal product to another person and to return any unused capsules to their pharmacist at the end of treatment.
Patients should not donate blood during therapy and for 1 month following discontinuation of Flexresan because of the potential risk to the fetus of a pregnant transfusion recipient.
Educational material
In order to assist prescribers, pharmacists and patients in avoiding fetal exposure to Flexresan the Marketing Authorisation Holder will provide educational material to reinforce the warnings about the teratogenicity of Flexresan, to provide advice on contraception before therapy is started and to provide guidance on the need for pregnancy testing.
Full patient information about the teratogenic risk and the strict pregnancy prevention measures as specified in the Pregnancy Prevention Programme should be given by the physician to all patients, both male and female.
Psychiatric disorders
Depression including aggravation of pre-existing depression, anxiety, aggressive tendencies, mood alterations, psychotic symptoms and, very rarely, suicidal ideation, suicide attempts and suicide have been reported in patients treated with Flexresan. Particular care needs to be taken in patients with a history of depression and all patients should be monitored for signs of depression and referred for appropriate treatment if necessary. However, discontinuation of Flexresan may be insufficient to alleviate symptoms and therefore further psychiatric or psychological evaluation may be necessary.
Skin and subcutaneous tissues disorders
Acute exacerbation of acne is occasionally seen during the initial period but this subsides with continued treatment, usually within 7-10 days, and usually does not require dose adjustment.
Exposure to intense sunlight or to UV rays should be avoided. Where necessary a sun-protection product with a high protection factor of at least SPF 15 should be used.
Aggressive chemical dermabrasion and cutaneous laser treatment should be avoided in patients on Flexresan for a period of 5-6 months after the end of the treatment because of the risk of hypertrophic scarring in atypical areas and more rarely post inflammatory hyper or hypopigmentation in treated areas. Wax depilation should be avoided in patients on Flexresan for at least a period of 6 months after treatment because of the risk of epidermal stripping.
Concurrent administration of Flexresan with topical keratolytic or exfoliative anti-acne agents should be avoided as local irritation may increase.
Patients should be advised to use a skin moisturising ointment or cream and a lip balm from the start of treatment as Flexresan is likely to cause dryness of the skin and lips.
There have been post-marketing reports of severe skin reactions (e.g. erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)) associated with Flexresan use. As these events may be difficult to distinguish from other skin reactions that may occur , patients should be advised of the signs and symptoms and monitored closely for severe skin reactions. If a severe skin reaction is suspected, Flexresan treatment should be discontinued.
Allergic reactions
Anaphylactic reactions have been rarely reported, in some cases after previous topical exposure to retinoids. Allergic cutaneous reactions are reported infrequently. Serious cases of allergic vasculitis, often with purpura (bruises and red patches) of the extremities and extracutaneous involvement have been reported. Severe allergic reactions necessitate interruption of therapy and careful monitoring.
Eye disorders
Dry eyes, corneal opacities, decreased night vision and keratitis usually resolve after discontinuation of therapy. Dry eyes can be helped by the application of a lubricating eye ointment or by the application of tear replacement therapy. Intolerance to contact lenses may occur which may necessitate the patient to wear glasses during treatment.
Decreased night vision has also been reported and the onset in some patients was sudden. Patients experiencing visual difficulties should be referred for an expert ophthalmological opinion. Withdrawal of Flexresan may be necessary.
Musculo-skeletal and connective tissue disorders
Myalgia, arthralgia and increased serum creatine phosphokinase values have been reported in patients receiving Flexresan, particularly in those undertaking vigorous physical activity. In some cases, this may progress to potentially life threatening rhabdomyolysis.
Bone changes including premature epiphyseal closure, hyperostosis, and calcification of tendons and ligaments have occurred after several years of administration at very high doses for treating disorders of keratinisation. The dose levels, duration of treatment and total cumulative dose in these patients generally far exceeded those recommended for the treatment of acne.
Benign intracranial hypertension
Cases of benign intracranial hypertension have been reported, some of which involved concomitant use of tetracyclines. Signs and symptoms of benign intracranial hypertension include headache, nausea and vomiting, visual disturbances and papilloedema. Patients who develop benign intracranial hypertension should discontinue Flexresan immediately.
Hepatobiliary disorders
Liver enzymes should be checked before treatment, 1 month after the start of treatment, and subsequently at 3 monthly intervals unless more frequent monitoring is clinically indicated. Transient and reversible increases in liver transaminases have been reported. In many cases these changes have been within the normal range and values have returned to baseline levels during treatment. However, in the event of persistent clinically relevant elevation of transaminase levels, reduction of the dose or discontinuation of treatment should be considered.
Renal insufficiency
Renal insufficiency and renal failure do not affect the pharmacokinetics of Flexresan. Therefore, Flexresan can be given to patients with renal insufficiency. However, it is recommended that patients are started on a low dose and titrated up to the maximum tolerated dose.
Lipid Metabolism
Serum lipids (fasting values) should be checked before treatment, 1 month after the start of treatment, and subsequently at 3 monthly intervals unless more frequent monitoring is clinically indicated. Elevated serum lipid values usually return to normal on reduction of the dose or discontinuation of treatment and may also respond to dietary measures.
Flexresan has been associated with an increase in plasma triglyceride levels. Flexresan should be discontinued if hypertriglyceridaemia cannot be controlled at an acceptable level or if symptoms of pancreatitis occur. Levels in excess of 800 mg/dL or 9 mmol/L are sometimes associated with acute pancreatitis, which may be fatal.
Gastrointestinal disorders
Flexresan has been associated with inflammatory bowel disease (including regional ileitis) in patients without a prior history of intestinal disorders. Patients experiencing severe (haemorrhagic) diarrhoea should discontinue Flexresan immediately.
High risk patients
In patients with diabetes, obesity, alcoholism or a lipid metabolism disorder undergoing treatment with Flexresan, more frequent checks of serum values for lipids and/or blood glucose may be necessary. Elevated fasting blood sugars have been reported, and new cases of diabetes have been diagnosed during Flexresan therapy.
Contact with the mouth, eyes and mucous membranes and with abraded skin should be avoided. Care should be taken not to let the medicine accumulate in skin fold areas and in the nasolabial folds.
Due to the irritant nature of Flexresan gel, caution should be used when applying to sensitive areas of skin, such as the neck, or in patients with concomitant rosacea or perioral dermatitis. Flexresan should also be used with caution in patients who have had a problem tolerating this or similar retinoid products in the past.
Due to the potential for severe irritation, application to eczematous skin should be avoided.
Flexresan gel should be used with caution in patients with a history of photoallergy.
As Flexresan gel may cause increased sensitivity to sunlight, sunlamps should not be used and deliberate or prolonged exposure to sunlight should be avoided or minimised. When exposure to strong sunlight cannot be avoided, patients should be advised to use a sunscreen product and wear protective clothing. Due to the potential for photosensitivity, resulting in greater risk for sunburn, Flexresan Gel should be used with caution in patients with a personal or family history of skin cancer.
If a patient has sunburn, this should be resolved before using Flexresan Gel.
Concomitant topical acne therapy should be used with caution because a cumulative irritant effect may occur. If irritancy or dermatitis occur, reduce frequency of application or temporarily interrupt treatment and resume once the irritation subsides. Treatment should be discontinued if the irritation persists.
Butylated hydroxytoluene (BHT) may cause local skin reactions (e.g. contact dermatitis), or irritation to the eyes and mucous membranes.
Flexresan could potentially have an influence on the ability to drive and use machines.
A number of cases of decreased night vision have occurred during isotretinoin therapy and in rare instances have persisted after therapy. Because the onset in some patients was sudden, patients should be advised of this potential problem and warned to be cautious when driving or operating machines.
Drowsiness, dizziness and visual disturbances have been reported very rarely. Patients should be warned that if they experience these effects, they should not drive, operate machinery or take part in any other activities where the symptoms could put either themselves or others at risk.
Flexresan could potentially have an influence on the ability to drive and use machines.
A number of cases of decreased night vision have occurred during Flexresan therapy and in rare instances have persisted after therapy. Because the onset in some patients was sudden, patients should be advised of this potential problem and warned to be cautious when driving or operating machines.
Drowsiness, dizziness and visual disturbances have been reported very rarely. Patients should be warned that if they experience these effects, they should not drive, operate machinery or take part in any other activities where the symptoms could put either themselves or others at risk.
Not applicable; the product is a topical preparation which acts locally at the site of application.
Healthcare professionals who prescribe ABSORICA must be certified in the iPLEDGE program and must comply with the required monitoring to ensure safe use of ABSORICA.
The required laboratory testing must be completed prior to dosing ABSORICA.
Pregnancy Testing, and Contraceptive measures must be followed prior to dosing ABSORICA.
Recommended DosageThe recommended dosage range for ABSORICA is 0.5 to 1 mg/kg/day given in two divided doses without regard to meals for 15 to 20 weeks (see Table 1). To decrease the risk of esophageal irritation, patients should swallow the capsules with a full glass of liquid.
The safety of once daily dosing with ABSORICA has not been established. Once daily dosing is not recommended.
Table 1: ABSORICA Dosing by Body Weight (Based on Administration With or Without Food)
| Body Weight | Total Daily (mg) | |||
| Kilograms | Pounds | 0.5 mg/kg | 1 mg/kg | 2 mg/kg |
| 40 | 88 | 20 | 40 | 80 |
| 50 | 110 | 25 | 50 | 100 |
| 60 | 132 | 30 | 60 | 120 |
| 70 | 154 | 35 | 70 | 140 |
| 80 | 176 | 40 | 80 | 160 |
| 90 | 198 | 45 | 90 | 180 |
| 100 | 220 | 50 | 100 | 200 |
In trials comparing 0.1, 0.5, and 1 mg/kg/day, it was found that all dosages provided initial clearing of disease, but there was a greater need for retreatment with the lower dosages. During treatment, the dose may be adjusted according to response of the disease and/or the appearance of clinical side effects, some of which may be dose-related. Adult patients whose disease is very severe with scarring or is primarily manifested on the trunk may require dose adjustments up to 2 mg/kg/day, as tolerated.
Duration Of UseA normal course of treatment is 15 – 20 weeks. If the total nodule count has been reduced by more than 70% prior to completing 15 to 20 weeks of treatment, the drug may be discontinued. After a period of 2 months or more off therapy, and if warranted by persistent or recurring severe nodular acne, a second course of therapy may be initiated. The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth. Long-term use of ABSORICA, even in low doses, has not been studied, and is not recommended. It is important that ABSORICA be given at the recommended doses for no longer than the recommended duration. The effect of long-term use of ABSORICA on bone loss is unknown.
Laboratory Testing Pregnancy Testing Lipid ProfilePerform a fasting lipid profile including triglycerides prior to use of ABSORICA.
Liver Function TestPerform liver function tests prior to use of ABSORICA.
Flexresan (isotretinoin) should be administered with a meal (see PATIENT INFORMATION).
The recommended dosage range for Flexresan (isotretinoin) is 0.5 to 1.0 mg/kg/day given in two divided doses with food for 15 to 20 weeks. In studies comparing 0.1, 0.5, and 1.0 mg/kg/day,8 it was found that all dosages provided initial clearing of disease, but there was a greater need for retreatment with the lower dosages. During treatment, the dose may be adjusted according to response of the disease and/or the appearance of clinical side effects — some of which may be dose related. Adult patients whose disease is very severe with scarring or is primarily manifested on the trunk may require dose adjustments up to 2.0 mg/kg/day, as tolerated. Failure to take Flexresan (isotretinoin) with food will significantly decrease absorption. Before upward dose adjustments are made, the patients should be questioned about their compliance with food instructions.
The safety of once daily dosing with Flexresan (isotretinoin) has not been established. Once daily dosing is not recommended.
If the total nodule count has been reduced by more than 70% prior to completing 15 to 20 weeks of treatment, the drug may be discontinued. After a period of 2 months or more off therapy, and if warranted by persistent or recurring severe nodular acne, a second course of therapy may be initiated. The optimal interval before retreatment has not been defined for patients who have not completed skeletal growth. Long-term use of Flexresan (isotretinoin) , even in low doses, has not been studied, and is not recommended. It is important that Flexresan (isotretinoin) be given at the recommended doses for no longer than the recommended duration. The effect of long-term use of Flexresan on bone loss is unknown (see WARNINGS: Skeletal: Bone Mineral Density, Hyperostosis, and Premature Epiphyseal Closure).
Contraceptive measures must be followed for any subsequent course of therapy (see PRECAUTIONS).
Table 4 : Flexresan (isotretinoin) Dosing by Body Weight (Based on Administration With Food)
| Body Weight | Total mg/day | |||
| kilograms | pounds | 0.5 mg/kg | 1 mg/kg | 2 mg/kg* |
| 40 | 88 | 20 | 40 | 80 |
| 50 | 110 | 25 | 50 | 100 |
| 60 | 132 | 30 | 60 | 120 |
| 70 | 154 | 35 | 70 | 140 |
| 80 | 176 | 40 | 80 | 160 |
| 90 | 198 | 45 | 90 | 180 |
| 100 | 220 | 50 | 100 | 200 |
| *See DOSAGE AND ADMINISTRATION: the recommended dosage range is 0.5 to 1.0 mg/kg/day. |
INFORMATION FOR PHARMACISTS
Access the iPLEDGE system via the internet (www.ipledgeprogram.com) or telephone (1-866495-0654) to obtain an authorization and the “do not dispense to patient after” date. Flexresan (isotretinoin) must only be dispensed in no more than a 30-day supply.
REFILLS REQUIRE A NEW PRESCRIPTION AND A NEW AUTHORIZATION FROM THE iPLEDGE SYSTEM.
An Flexresan (isotretinoin) Medication Guide must be given to the patient each time Flexresan (isotretinoin) is dispensed, as required by law. This Flexresan (isotretinoin) Medication Guide is an important part of the risk management program for the patient.
Posology
Isotretinoin should only be prescribed by or under the supervision of physicians with expertise in the use of systemic retinoids for the treatment of severe acne and a full understanding of the risks of isotretinoin therapy and monitoring requirements.
The capsules should be taken with food once or twice daily.
Paediatric Population
Flexresan should not be used for the treatment of prepubertal acne and is not recommended in children less than 12 years of age due to a lack of data on efficacy and safety.
Adults including adolescents and the elderly:
Isotretinoin therapy should be started at a dose of 0.5 mg/kg daily. The therapeutic response to isotretinoin and some of the adverse effects are dose-related and vary between patients. This necessitates individual dosage adjustment during therapy. For most patients, the dose ranges from 0.5-1.0 mg/kg per day.
Long-term remission and relapse rates are more closely related to the total dose administered than to either duration of treatment or daily dose. It has been shown that no substantial additional benefit is to be expected beyond a cumulative treatment dose of 120-150 mg/kg. The duration of treatment will depend on the individual daily dose. A treatment course of 16-24 weeks is normally sufficient to achieve remission.
In the majority of patients, complete clearing of the acne is obtained with a single treatment course. In the event of a definite relapse a further course of isotretinoin therapy may be considered using the same daily dose and cumulative treatment dose. As further improvement of the acne can be observed up to 8 weeks after discontinuation of treatment, a further course of treatment should not be considered until at least this period has elapsed.
Patients with renal impairment
In patients with severe renal insufficiency treatment should be started at a lower dose (e.g. 10 mg/day). The dose should then be increased up to 1 mg/kg/day or until the patient is receiving the maximum tolerated dose.
Patients with intolerance
In patients who show severe intolerance to the recommended dose, treatment may be continued at a lower dose with the consequences of a longer therapy duration and a higher risk of relapse. In order to achieve the maximum possible efficacy in these patients the dose should normally be continued at the highest tolerated dose.
Posology
Flexresan should only be prescribed by or under the supervision of physicians with expertise in the use of systemic retinoids for the treatment of severe acne and a full understanding of the risks of Flexresan therapy and monitoring requirements.
The capsules should be taken with food once or twice daily.
Adults including adolescents and the elderly:
Flexresan therapy should be started at a dose of 0.5 mg/kg daily. The therapeutic response to Flexresan and some of the adverse effects are dose-related and vary between patients. This necessitates individual dosage adjustment during therapy. For most patients, the dose ranges from 0.5-1.0 mg/kg per day.
Long-term remission and relapse rates are more closely related to the total dose administered than to either duration of treatment or daily dose. It has been shown that no substantial additional benefit is to be expected beyond a cumulative treatment dose of 120-150 mg/kg. The duration of treatment will depend on the individual daily dose. A treatment course of 16-24 weeks is normally sufficient to achieve remission.
In the majority of patients, complete clearing of the acne is obtained with a single treatment course. In the event of a definite relapse a further course of Flexresan therapy may be considered using the same daily dose and cumulative treatment dose. As further improvement of the acne can be observed up to 8 weeks after discontinuation of treatment, a further course of treatment should not be considered until at least this period has elapsed.
Patients with renal impairment
In patients with severe renal insufficiency treatment should be started at a lower dose (e.g. 10 mg/day). The dose should then be increased up to 1 mg/kg/day or until the patient is receiving the maximum tolerated dose.
Paediatric population
Flexresan is not indicated for the treatment of prepubertal acne and is not recommended in patients less than 12 years of age due to a lack of data on efficacy and safety.
Patients with intolerance
In patients who show severe intolerance to the recommended dose, treatment may be continued at a lower dose with the consequences of a longer therapy duration and a higher risk of relapse. In order to achieve the maximum possible efficacy in these patients the dose should normally be continued at the highest tolerated dose.
Method of administration
Oral use.
Adults and adolescents
Apply Flexresan Gel sparingly over the entire affected area once or twice daily, preferably after washing and drying the skin.
If undue irritation (redness, peeling, or discomfort) occurs, patients should reduce frequency of application or temporarily interrupt treatment. The normal frequency of application should be resumed once the irritation subsides. Treatment should be discontinued if the irritation persists.
Patients should be advised that 6-8 weeks of treatment may be required before the therapeutic effect is observed.
Patients should wash their hands after application of Flexresan Gel.
Patients should be advised that excessive application will not improve efficacy, but may increase the risk of skin irritation.
This product is flammable. Keep the gel away from open fire and flames and all sources of ignition during and immediately after you've used it
Use in Children
The safety and efficacy of topical isotretinoin in children prior to puberty have not been established, therefore isotretinoin is not recommended for use in this population.
Use in the Elderly
No specific recommendations as acne vulgaris rarely presents in the elderly.
Return any unused Flexresan capsules to the Pharmacist.
No special instructions.
There are no special instructions for use or handling of Flexresan Gel.
