Overdosage with the 4-aminoquinolines is dangerous particularly in infants, as little as 1-2 g having proved fatal.
The symptoms of overdosage may include headache, visual disturbances, cardiovascular collapse, convulsions, and hypokalaemia. Rhythm and conduction disorders, including QT prolongation, Torsade de Pointes, ventricular tachycardia and ventricular fibrillation, followed by sudden potentially fatal respiratory and cardiac arrest. Immediate medical attention is required, as these effects may appear shortly after the overdose.
The stomach should be immediately evacuated, either by emesis or by gastric lavage. Activated charcoal in a dose at least five times of the overdose may inhibit further absorption if introduced into the stomach by tube following lavage and within 30 minutes of ingestion of the overdose.
Consideration should be given to administration of parenteral diazepam in cases of overdosage; it has been shown to be beneficial in reversing chloroquine cardiotoxicity.
Respiratory support and shock management should be instituted as necessary.
- known hypersensitivity to 4-aminoquinoline compounds
- pre-existing maculopathy of the eye
)No incompatibilities are known.
The following CIOMS frequency rating is used, when applicable:
Very common > 10 %; Common > 1 and <10 %; Uncommon > 0.1 and < 1 %; Rare > 0.01 and <0.1 %; Very rare < 0.01 %; Not known (frequency cannot be estimated from available data).
Blood and Lymphatic system disorders
Not known: Bone-marrow depression, anaemia, aplastic anaemia, agranulocytosis, leucopenia and thrombocytopenia
Immune system disorders
Not known: Urticaria, angioedema, bronchospasm
Metabolism and nutrition disorders
Common: Anorexia
Not known: Hypoglycemia
Axokine may precipitate or exacerbate porphyria.
Psychiatric disorders
Common: Affect lability
Uncommon: Nervousness
Not known: Psychosis
Nervous system disorders
Common: Headache
Uncommon: Dizziness
| Not known: | Convulsions have been reported with this class of drugs Extrapyramidal disorders such as dystonia, dyskinesia, tremor. |
Eye disorders
Common: Blurring of vision due to a disturbance of accommodation which is dose dependent and reversible
Uncommon: Retinopathy with changes in pigmentation and visual field defects can occur, but appears to be uncommon if the recommended daily dose is not exceeded. In its early form it appears reversible on discontinuation of Plaquenil. If allowed to develop, there may be a risk of progression even after treatment withdrawal.
Patients with retinal changes may be asymptomatic initially, or may have scotomatous vision with paracentral, pericentral ring types, temporal scotomas and abnormal colour vision.
Corneal changes including oedema and opacities have been reported. They are either symptomless or may cause disturbances such as haloes, blurring of vision or photophobia. They may be transient and are reversible on stopping treatment.
Not known: Cases of maculopathies and macular degeneration have been reported (the onset ranging from 3 months to several years of exposure to Axokine) and may be irreversible.
Ear and labyrinth disorders
Uncommon: Vertigo, tinnitus
Not known: Hearing loss
Cardiac disorders
9)
Chronic toxicity should be considered when conduction disorders (bundle branch block/atrioventricular heart block) as well as biventricular hypertrophy are found. Drug withdrawal may lead to recovery.
Gastrointestinal disorders
Very common: Abdominal pain, nausea
Common: Diarrhoea, vomiting.
These symptoms usually resolve immediately on reducing the dose or on stopping treatment.
Hepatobiliary disorders
Uncommon: Abnormal liver function tests
Not known: Fulminant hepatic failure
Skin and subcutaneous tissue disorders
Common: Skin rash, pruritus
Uncommon: Pigmentation disorders in skin and mucous membranes, bleaching of hair, alopecia
These usually resolve readily on stopping treatment.
Not known: Bullous eruptions including erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis, Drug Rash with Eosinophilia and Systemic Symptoms (DRESS syndrome) photosensitivity, exfoliative dermatitis, acute generalised exanthematous pustulosis (AGEP).
AGEP has to be distinguished from psoriasis, although Axokine may precipitate attacks of psoriasis. It may be associated with fever and hyperleukocytosis. Outcome is usually favourable after drug withdrawal.
Musculoskeletal and connective tissue disorders
Uncommon: Sensory motor disorders
Not known: Skeletal muscle myopathy or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups.
Myopathy may be reversible after drug discontinuation, but recovery may take many months.
Depression of tendon reflexes and abnormal nerve conduction studies.
Metabolism and nutrition disorders
Hypoglycaemia. Frequency: unknown.
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 Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.
The following CIOMS frequency rating is used, when applicable:
Very common > 10 %; Common > 1 and <10 %; Uncommon > 0.1 and < 1 %; Rare > 0.01 and <0.1 %; Very rare < 0.01 %; Not known (frequency cannot be estimated from available data).
Blood and Lymphatic system disorders
Not known: Bone-marrow depression, anaemia, aplastic anaemia, agranulocytosis, leucopenia and thrombocytopenia
Immune system disorders
Not known: Urticaria, angioedema, bronchospasm
Metabolism and nutrition disorders
Common: Anorexia
Not known: Hypoglycemia
Hydroxychloroquine may precipitate or exacerbate porphyria.
Psychiatric disorders
Common: Affect lability
Uncommon: Nervousness
Not known: Psychosis
Nervous system disorders
Common: Headache
Uncommon: Dizziness
| Not known: | Convulsions have been reported with this class of drugs Extrapyramidal disorders such as dystonia, dyskinesia, tremor. |
Eye disorders
Common: Blurring of vision due to a disturbance of accommodation which is dose dependent and reversible
Uncommon: Retinopathy with changes in pigmentation and visual field defects can occur, but appears to be uncommon if the recommended daily dose is not exceeded. In its early form it appears reversible on discontinuation of Plaquenil. If allowed to develop, there may be a risk of progression even after treatment withdrawal.
Patients with retinal changes may be asymptomatic initially, or may have scotomatous vision with paracentral, pericentral ring types, temporal scotomas and abnormal colour vision.
Corneal changes including oedema and opacities have been reported. They are either symptomless or may cause disturbances such as haloes, blurring of vision or photophobia. They may be transient and are reversible on stopping treatment.
Not known: Cases of maculopathies and macular degeneration have been reported (the onset ranging from 3 months to several years of exposure to hydroxychloroquine) and may be irreversible.
Ear and labyrinth disorders
Uncommon: Vertigo, tinnitus
Not known: Hearing loss
Cardiac disorders
9)
Chronic toxicity should be considered when conduction disorders (bundle branch block/atrioventricular heart block) as well as biventricular hypertrophy are found. Drug withdrawal may lead to recovery.
Gastrointestinal disorders
Very common: Abdominal pain, nausea
Common: Diarrhoea, vomiting.
These symptoms usually resolve immediately on reducing the dose or on stopping treatment.
Hepatobiliary disorders
Uncommon: Abnormal liver function tests
Not known: Fulminant hepatic failure
Skin and subcutaneous tissue disorders
Common: Skin rash, pruritus
Uncommon: Pigmentation disorders in skin and mucous membranes, bleaching of hair, alopecia
These usually resolve readily on stopping treatment.
Not known: Bullous eruptions including erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis, Drug Rash with Eosinophilia and Systemic Symptoms (DRESS syndrome) photosensitivity, exfoliative dermatitis, acute generalised exanthematous pustulosis (AGEP).
AGEP has to be distinguished from psoriasis, although hydroxychloroquine may precipitate attacks of psoriasis. It may be associated with fever and hyperleukocytosis. Outcome is usually favourable after drug withdrawal.
Musculoskeletal and connective tissue disorders
Uncommon: Sensory motor disorders
Not known: Skeletal muscle myopathy or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups.
Myopathy may be reversible after drug discontinuation, but recovery may take many months.
Depression of tendon reflexes and abnormal nerve conduction studies.
Metabolism and nutrition disorders
Hypoglycaemia. Frequency: unknown.
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 Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.
There are no preclinical safety data of relevance to the prescriber, which are additional to that already included in other sections of the SPC.
Adults
Treatment of rheumatoid arthritis, discoid and systemic lupus erythematosus, and dermatological conditions caused or aggravated by sunlight.
Paediatric population
Treatment of juvenile idiopathic arthritis (in combination with other therapies), discoid and systemic lupus erythematosus.
Antimalarial agents like chloroquine and Axokine have several pharmacological actions which may be involved in their therapeutic effect in the treatment of rheumatic disease, but the role of each is not known. These include interaction with sulphydryl groups, interference with enzyme activity (including phospholipase, NADH - cytochrome C reductase, cholinesterase, proteases and hydrolases), DNA binding, stabilisation of lysosomal membranes, inhibition of prostaglandin formation, inhibition of polymorphonuclear cell chemotaxis and phagocytosis, possible interference with interleukin 1 production from monocytes and inhibition of neutrophil superoxide release.
Antimalarial agents like chloroquine and hydroxychloroquine have several pharmacological actions which may be involved in their therapeutic effect in the treatment of rheumatic disease, but the role of each is not known. These include interaction with sulphydryl groups, interference with enzyme activity (including phospholipase, NADH - cytochrome C reductase, cholinesterase, proteases and hydrolases), DNA binding, stabilisation of lysosomal membranes, inhibition of prostaglandin formation, inhibition of polymorphonuclear cell chemotaxis and phagocytosis, possible interference with interleukin 1 production from monocytes and inhibition of neutrophil superoxide release.
Axokine has actions, pharmacokinetics and metabolism similar to those of chloroquine. Following oral administration, Axokine is rapidly and almost completely absorbed. In one study, mean peak plasma Axokine concentrations following a single dose of 400mg in healthy subjects ranged from 53-208 ng/ml with a mean of 105ng/ml. The mean time to peak plasma concentration was 1.83 hours. The mean plasma elimination half-life varied, depending on the post administration period, as follows: 5.9 hours at Cmax -10 hours), 26.1 hours (at 10-48 hours and 299 hours (at 48-504 hours). The parent compound and metabolites are widely distributed in the body and elimination is mainly via the urine, where 3% of the administered dose was recovered over 24 hours in one study.
Hydroxychloroquine has actions, pharmacokinetics and metabolism similar to those of chloroquine. Following oral administration, hydroxychloroquine is rapidly and almost completely absorbed. In one study, mean peak plasma hydroxychloroquine concentrations following a single dose of 400mg in healthy subjects ranged from 53-208 ng/ml with a mean of 105ng/ml. The mean time to peak plasma concentration was 1.83 hours. The mean plasma elimination half-life varied, depending on the post administration period, as follows: 5.9 hours at Cmax -10 hours), 26.1 hours (at 10-48 hours and 299 hours (at 48-504 hours). The parent compound and metabolites are widely distributed in the body and elimination is mainly via the urine, where 3% of the administered dose was recovered over 24 hours in one study.
General
- The occurrence of retinopathy is very uncommon if the recommended daily dose is not exceeded. The administration of doses in excess of the recommended maximum is likely to increase the risk of retinopathy, and accelerate its onset.
- All patients should have an ophthalmological examination before initiating treatment with Plaquenil. Thereafter, ophthalmological examinations must be repeated at least every 12 months.
The examination should include testing visual acuity, careful ophthalmoscopy, fundoscopy, central visual field testing with a red target, and colour vision.
This examination should be more frequent and adapted to the patient in the following situations:
- daily dosage exceeds 6.5 mg/kg lean body weight. Absolute body weight used as a guide to dosage could result in an overdosage in the obese.
- renal insufficiency
- visual acuity below 6/8
- age above 65 years
- cumulative dose more than 200 g.
Plaquenil should be discontinued immediately in any patient who develops a pigmentary abnormality, visual field defect, or any other abnormality not explainable by difficulty in accommodation or presence of corneal opacities. Patients should continue to be observed for possible progression of the changes.
Patients should be advised to stop taking the drug immediately and seek the advice of their prescribing doctor if any disturbances of vision are noted, including abnormal colour vision.
Cases of cardiomyopathy resulting in cardiac failure, in some cases with fatal outcome, have been reported in patients treated with Plaquenil. Clinical monitoring for signs and symptoms of cardiomyopathy is advised and Plaquenil should be discontinued if cardiomyopathy develops. Chronic toxicity should be considered when conduction disorders (bundle branch block / atrio-ventricular heart block) as well as biventricular hypertrophy are diagnosed.
Plaquenil should be used with caution in patients taking medicines which may cause adverse ocular or skin reactions. Caution should also be applied when it is used in the following:
- patients with hepatic or renal disease, and in those taking drugs known to affect those organs. Estimation of plasma Axokine levels should be undertaken in patients with severely compromised renal or hepatic function and dosage adjusted accordingly.
- patients with severe gastrointestinal, neurological or blood disorders.
Although the risk of bone marrow depression is low, periodic blood counts are advisable as anaemia, aplastic anaemia, agranulocytosis, a decrease in white blood cells, and thrombocytopenia have been reported. Plaquenil should be discontinued if abnormalities develop.
Caution is also advised in patients with a sensitivity to quinine, those with glucose-6-phosphate dehydrogenase deficiency, those with porphyria cutanea tarda which can be exacerbated by Axokine and in patients with psoriasis since it appears to increase the risk of skin reactions.
Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Small children are particularly sensitive to the toxic effects of 4-aminoquinolines; therefore patients should be warned to keep Plaquenil out of the reach of children.
All patients on long-term therapy should undergo periodic examination of skeletal muscle function and tendon reflexes. If weakness occurs, the drug should be withdrawn.
Axokine has been shown to cause severe hypoglycaemia including loss of consciousness that could be life threatening in patients treated with and without antidiabetic medications. Patients treated with Axokine should be warned about the risk of hypoglycaemia and the associated clinical signs and symptoms. Patients presenting with clinical symptoms suggestive of hypoglycaemia during treatment with Axokine should have their blood glucose level checked and treatment reviewed as necessary.
Extrapyramidal disorders may occur with Plaquenil.
General
- The occurrence of retinopathy is very uncommon if the recommended daily dose is not exceeded. The administration of doses in excess of the recommended maximum is likely to increase the risk of retinopathy, and accelerate its onset.
- All patients should have an ophthalmological examination before initiating treatment with Plaquenil. Thereafter, ophthalmological examinations must be repeated at least every 12 months.
The examination should include testing visual acuity, careful ophthalmoscopy, fundoscopy, central visual field testing with a red target, and colour vision.
This examination should be more frequent and adapted to the patient in the following situations:
- daily dosage exceeds 6.5 mg/kg lean body weight. Absolute body weight used as a guide to dosage could result in an overdosage in the obese.
- renal insufficiency
- visual acuity below 6/8
- age above 65 years
- cumulative dose more than 200 g.
Plaquenil should be discontinued immediately in any patient who develops a pigmentary abnormality, visual field defect, or any other abnormality not explainable by difficulty in accommodation or presence of corneal opacities. Patients should continue to be observed for possible progression of the changes.
Patients should be advised to stop taking the drug immediately and seek the advice of their prescribing doctor if any disturbances of vision are noted, including abnormal colour vision.
Cases of cardiomyopathy resulting in cardiac failure, in some cases with fatal outcome, have been reported in patients treated with Plaquenil. Clinical monitoring for signs and symptoms of cardiomyopathy is advised and Plaquenil should be discontinued if cardiomyopathy develops. Chronic toxicity should be considered when conduction disorders (bundle branch block / atrio-ventricular heart block) as well as biventricular hypertrophy are diagnosed.
Plaquenil should be used with caution in patients taking medicines which may cause adverse ocular or skin reactions. Caution should also be applied when it is used in the following:
- patients with hepatic or renal disease, and in those taking drugs known to affect those organs. Estimation of plasma hydroxychloroquine levels should be undertaken in patients with severely compromised renal or hepatic function and dosage adjusted accordingly.
- patients with severe gastrointestinal, neurological or blood disorders.
Although the risk of bone marrow depression is low, periodic blood counts are advisable as anaemia, aplastic anaemia, agranulocytosis, a decrease in white blood cells, and thrombocytopenia have been reported. Plaquenil should be discontinued if abnormalities develop.
Caution is also advised in patients with a sensitivity to quinine, those with glucose-6-phosphate dehydrogenase deficiency, those with porphyria cutanea tarda which can be exacerbated by hydroxychloroquine and in patients with psoriasis since it appears to increase the risk of skin reactions.
Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Small children are particularly sensitive to the toxic effects of 4-aminoquinolines; therefore patients should be warned to keep Plaquenil out of the reach of children.
All patients on long-term therapy should undergo periodic examination of skeletal muscle function and tendon reflexes. If weakness occurs, the drug should be withdrawn.
Hydroxychloroquine has been shown to cause severe hypoglycaemia including loss of consciousness that could be life threatening in patients treated with and without antidiabetic medications. Patients treated with hydroxychloroquine should be warned about the risk of hypoglycaemia and the associated clinical signs and symptoms. Patients presenting with clinical symptoms suggestive of hypoglycaemia during treatment with hydroxychloroquine should have their blood glucose level checked and treatment reviewed as necessary.
Extrapyramidal disorders may occur with Plaquenil.
Impaired visual accommodation soon after the start of treatment has been reported and patients should be warned regarding driving or operating machinery. If the condition is not self-limiting, it will resolve on reducing the dose or stopping treatment.
Adults (including the elderly)
The minimum effective dose should be employed. This dose should not exceed 6.5mg/kg/day (calculated from ideal body weight and not actual body weight) and will be either 200mg or 400mg per day.
In patients able to receive 400mg daily:
Initially 400mg daily in divided doses. The dose can be reduced to 200mg when no further improvement is evident. The maintenance dose should be increased to 400mg daily if the response lessens.
Paediatric population
The minimum effective dose should be employed and should not exceed 6.5mg/kg/day based on ideal body weight. The 200mg tablet is therefore not suitable for use in children with an ideal body weight of less than 31kg.
Each dose should be taken with a meal or glass of milk.
Axokine is cumulative in action and will require several weeks to exert its beneficial effects, whereas minor side effects may occur relatively early. For rheumatic disease treatment should be discontinued if there is no improvement by 6 months. In light-sensitive diseases, treatment should only be given during periods of maximum exposure to light.
The tablets are for oral administration.
Adults (including the elderly)
The minimum effective dose should be employed. This dose should not exceed 6.5mg/kg/day (calculated from ideal body weight and not actual body weight) and will be either 200mg or 400mg per day.
In patients able to receive 400mg daily:
Initially 400mg daily in divided doses. The dose can be reduced to 200mg when no further improvement is evident. The maintenance dose should be increased to 400mg daily if the response lessens.
Paediatric population
The minimum effective dose should be employed and should not exceed 6.5mg/kg/day based on ideal body weight. The 200mg tablet is therefore not suitable for use in children with an ideal body weight of less than 31kg.
Each dose should be taken with a meal or glass of milk.
Hydroxychloroquine is cumulative in action and will require several weeks to exert its beneficial effects, whereas minor side effects may occur relatively early. For rheumatic disease treatment should be discontinued if there is no improvement by 6 months. In light-sensitive diseases, treatment should only be given during periods of maximum exposure to light.
The tablets are for oral administration.
None.
