a) Symptoms of overdose
Toxicity of methotrexate mainly affects the haematopoietic system.
b) Treatment measures in the case of overdose
Calcium folinate is the specific antidote for neutralising the toxic undesirable effects of methotrexate.
In cases of accidental overdose, a dose of calcium folinate equal to or higher than the offending dose of methotrexate should be administered intravenously or intramuscularly within one hour and dosing continued until the serum levels of methotrexate are below 10-7 mol/l.
In cases of massive overdose, hydration and urinary alkalisation may be necessary to prevent precipitation of methotrexate and/or its metabolites in the renal tubules. Neither haemodialysis nor peritoneal dialysis has been shown to improve methotrexate elimination. Effective clearance of methotrexate has been reported with acute, intermittent haemodialysis using a high flux dialyser.
Methotrexate-Teva PEN is contraindicated in the case of
- hypersensitivity to the active substance or to any of the excipients listed in section 6.1,
- severe liver impairment ,
- alcohol abuse,
- severe renal impairment ,
- pre-existing blood dyscrasias, such as bone marrow hypoplasia, leukopenia, thrombocytopenia, or significant anaemia,
- serious, acute or chronic infections such as tuberculosis, HIV or other immunodeficiency syndromes,
- ulcers of the oral cavity and known active gastrointestinal ulcer disease,
- pregnancy, breast-feeding ,
- concurrent vaccination with live vaccines.
In the absence of compatibility studies, this medicinal product must not be mixed with other medicinal products.
Summary of the safety profile
Most serious adverse reactions of methotrexate include bone marrow suppression, pulmonary toxicity, hepatotoxicity, renal toxicity, neurotoxicity, thromboembolic events, anaphylactic shock and Stevens-Johnson syndrome.
Most frequently (very common) observed adverse reactions of methotrexate include gastrointestinal disorders e.g. stomatitis, dyspepsia, abdominal pain, nausea, loss of appetite and abnormal liver function tests e.g. increased ALAT, ASAT, bilirubin, alkaline phosphatase. Other frequently (common) occurring adverse reactions are leukopenia, anaemia, thrombopenia, headache, tiredness, drowsiness, pneumonia, interstitial alveolitis/pneumonitis often associated with eosinophilia, oral ulcers, diarrhoea, exanthema, erythema and pruritus.
Tabulated list of adverse reactions
The most relevant undesirable effects are suppression of the haematopoietic system and gastrointestinal disorders.
The following headings are used to organise the undesirable effects in order of frequency:
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), not known (cannot be estimated from the available data)
Infections and infestations
Uncommon: Pharyngitis.
Rare: Infection (incl. reactivation of inactive chronic infection), sepsis, conjunctivitis.
Neoplasms benign, malignant and unspecified (including cysts and polyps)
Very rare: There have been reports of individual cases of lymphoma which subsided in a number of cases once treatment with methotrexate had been discontinued. In a recent study, it could not be established that methotrexate therapy increases the incidence of lymphomas.
Blood and lymphatic system disorders
Common: Leukopenia, anaemia, thrombopenia.
Uncommon: Pancytopenia.
Very rare: Agranulocytosis, severe courses of bone marrow depression.
Not known: Eosinophilia
Immune system disorders
Rare: Allergic reactions, anaphylactic shock, hypogammaglobulinaemia.
Metabolism and nutrition disorders
Uncommon: Precipitation of diabetes mellitus.
Psychiatric disorders
Uncommon: Depression, confusion.
Rare: Mood alterations.
Nervous system disorders
Common: Headache, tiredness, drowsiness.
Uncommon: Dizziness.
Very rare: Pain, muscular asthenia or paraesthesia in the extremities, changes in sense of taste (metallic taste), convulsions, meningism, acute aseptic meningitis, paralysis.
Not known: Encephalopathy/leukoencephalopathy.
Eye disorders
Rare: Visual disturbances.
Very rare: Impaired vision, Retinopathy.
Cardiac disorders
Rare: Pericarditis, pericardial effusion, pericardial tamponade.
Vascular disorders
Rare: Hypotension, thromboembolic events.
Respiratory, thoracic and mediastinal disorders
Common: Pneumonia, interstitial alveolitis/pneumonitis often associated with eosinophilia. Symptoms indicating potentially severe lung injury (interstitial pneumonitis) are: dry, not productive cough, short of breath and fever.
Rare: Pulmonary fibrosis, Pneumocystis carinii pneumonia, shortness of breath and bronchial asthma, pleural effusion.
Not known: Epistaxis.
Gastrointestinal disorders
Very common: Stomatitis, dyspepsia, nausea, loss of appetite, abdominal pain.
Common: Oral ulcers, diarrhoea.
Uncommon: Gastrointestinal ulcers and bleeding, enteritis, vomiting, pancreatitis.
Rare: Gingivitis.
Very rare: Haematemesis, haematorrhea, toxic megacolon.
Hepatobiliary disorders
Very common: Abnormal liver function tests (increased ALAT, ASAT, alkaline phosphatase and bilirubin).
Uncommon: Cirrhosis, fibrosis and fatty degeneration of the liver, decrease in serum albumin.
Rare: Acute hepatitis.
Very rare: Hepatic failure.
Skin and subcutaneous tissue disorders
Common: Exanthema, erythema, pruritus.
Uncommon: Photosensitisation, loss of hair, increase in rheumatic nodules, herpes zoster, vasculitis, herpetiform eruptions of the skin, urticaria.
Rare: Increased pigmentation, acne, petechiae, ecchymosis, allergic vasculitis.
Very rare: Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell's syndrome), increased pigmentary changes of the nails, acute paronychia, furunculosis, telangiectasia.
Musculoskeletal and connective tissue disorders
Uncommon: Arthralgia, myalgia, osteoporosis.
Rare: Stress fracture.
Renal and urinary disorders
Uncommon: Inflammation and ulceration of the urinary bladder, renal impairment, disturbed micturition.
Rare: Renal failure, oliguria, anuria, electrolyte disturbances.
Not known: Proteinuria.
Reproductive system and breast disorders
Uncommon: Inflammation and ulceration of the vagina.
Very rare: Loss of libido, impotence, gynaecomastia, oligospermia, impaired menstruation, vaginal discharge.
General disorders and administration site conditions
Rare: Fever, wound-healing impairment.
Not known: Asthenia.
The appearance and degree of severity of undesirable effects depends on the dosage level and the frequency of administration. However, as severe undesirable effects can occur even at lower doses, it is indispensable that patients are monitored regularly by the doctor at short intervals.
Subcutaneous application of methotrexate is locally well tolerated. Only mild local skin reactions (such as burning sensations, erythema, swelling, discolouration, pruritus, severe itching, pain) were observed, decreasing during therapy.
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.
Animal studies show that methotrexate impairs fertility, is embryo- and foetotoxic and teratogenic. Methotrexate is mutagenic in vivo and in vitro. As conventional carcinogenicity studies have not been performed and data from chronic toxicity studies in rodents are inconsistent, methotrexate is considered not classifiable as to its carcinogenicity to humans.
Methotrexate-Teva PEN is indicated for the treatment of
- active rheumatoid arthritis in adult patients,
- polyarthritic forms of severe, active juvenile idiopathic arthritis, when the response to nonsteroidal anti-inflammatory drugs (NSAIDs) has been inadequate,
- severe recalcitrant disabling psoriasis, which is not adequately responsive to other forms of therapy such as phototherapy, PUVA, and retinoids, and severe psoriatic arthritis in adult patients.
- mild to moderate Crohn's disease either alone or in combination with corticosteroids in adult patients refractory or intolerant to thiopurines.
Pharmacotherapeutic group: Folic acid analogues
ATC code: L01BA01
Antirheumatic medicinal product for the treatment of chronic, inflammatory rheumatic diseases and polyarthritic forms of juvenile idiopathic arthritis. Immunomodulating and anti-inflammatory agent for the treatment of Crohn's disease.
Mechanism of action
Methotrexate is a folic acid antagonist which belongs to the class of cytotoxic agents known as antimetabolites. It acts by the competitive inhibition of the enzyme dihydrofolate reductase and thus inhibits DNA synthesis. It has not yet been clarified, as to whether the efficacy of methotrexate, in the management of psoriasis, psoriasis arthritis, chronic polyarthritis, and Crohn's disease, is due to an anti-inflammatory or immunosuppressive effect and to which extent a methotrexate-induced increase in extracellular adenosine concentration at inflamed sites contributes to these effects.
International clinical guidelines reflect the use of methotrexate as a second choice for Crohn's disease patients that are intolerant or have failed to respond to first-line immunomodulating agents as azathioprine (AZA) or 6-mercaptopurine (6-MP).
The adverse events observed in the studies performed with methotrexate for Crohn's disease at cumulative doses have not shown a different safety profile of methotrexate than the profile it is already known. Therefore, similar cautions must be taken with the use of methotrexate for the treatment of Crohn's disease as in other rheumatic and non-rheumatic indications of methotrexate.
Absorption
Following oral administration, methotrexate is absorbed from the gastrointestinal tract. In case of low-dosed administration (dosages between 7.5 mg/m² and 80 mg/m² body surface area), the mean bioavailability is approx. 70 %, but considerable interindividual and intraindividual deviations are possible (25 - 100 %). Maximum serum concentrations are achieved after 1 - 2 hours.
Bioavailability of subcutaneous, intravenous and intramuscular injection is comparable and nearly 100 %.
Distribution
Approximately 50 % of methotrexate is bound to serum proteins. Upon being distributed into body tissues, high concentrations in the form of polyglutamates are found in the liver, kidneys and spleen in particular, which can be retained for weeks or months. When administered in small doses, methotrexate passes into the cerebrospinal fluid in minimal amounts. The terminal half-life is on average 6 - 7 hours and demonstrates considerable variation (3 - 17 hours). The half-life can be prolonged to 4 times the normal length in patients who possess a third distribution space (pleural effusion, ascites).
Biotransformation
Approx. 10 % of the administered methotrexate dose is metabolised intrahepatically. The principle metabolite is 7-hydroxymethotrexate.
Elimination
Excretion takes places, mainly in unchanged form, primarily renal via glomerular filtration and active secretion in the proximal tubulus.
Approx. 5 - 20 % methotrexate and 1 - 5 % 7-hydroxymethotrexate are eliminated biliary. There is pronounced enterohepatic circulation.
In the case of renal impairment, elimination is delayed significantly. Impaired elimination with regard to hepatic impairment is not known.
Patients must be clearly informed that the therapy has to be administered once a week, not every day.
Patients undergoing therapy should be subject to appropriate supervision so that signs of possible toxic effects or adverse reactions may be detected and evaluated with minimal delay. Therefore treatment with methotrexate should only be initiated and supervised by physicians whose knowledge and experience includes the use of antimetabolite therapy. Because of the possibility of severe or even fatal toxic reactions, the patient should be fully informed by the physician of the risks involved and the recommended safety measures.
Recommended examinations and safety measures
Before beginning or reinstituting methotrexate therapy after a rest period
Complete blood count with differential blood count and platelets, liver enzymes, bilirubin, serum albumin, chest x-ray and renal function tests. If clinically indicated, exclude tuberculosis and hepatitis.
During therapy (at least once a month during the first six months and every three months thereafter)
An increased monitoring frequency should be considered also when the dose is increased.
1. Examination of the mouth and throat for mucosal changes
2. Complete blood count with differential blood count and platelets. Haemopoietic suppression caused by methotrexate may occur abruptly and with apparently safe dosages. Any profound drop in white-cell or platelet counts indicates immediate withdrawal of the medicinal product and appropriate supportive therapy. Patients should be advised to report all signs and symptoms suggestive of infection. Patients taking simultaneous administration of haematotoxic medicinal products (e.g. leflunomide) should be monitored closely with blood count and platelets.
3. Liver function tests: Particular attention should be given to the appearance of liver toxicity. Treatment should not be instituted or should be discontinued if any abnormality of liver function tests, or liver biopsy, is present or develops during therapy. Such abnormalities should return to normal within two weeks after which treatment may be recommenced at the discretion of the physician. There is no evidence to support use of a liver biopsy to monitor hepatic toxicity in rheumatological indications.
For psoriasis patients the need of a liver biopsy prior to and during therapy is controversial. Further research is needed to establish whether serial liver chemistry tests or propeptide of type III collagen can detect hepatotoxicity sufficiently. The evaluation should be performed case by case and differentiate between patients with no risk factors and patients with risk factors such as excessive prior alcohol consumption, persistent elevation of liver enzymes, history of liver disease, family history of inheritable liver disease, diabetes mellitus, obesity, and history of significant exposure to hepatotoxic drugs or chemicals and prolonged Methotrexate treatment or cumulative doses of 1.5 g or more.
Check of liver-related enzymes in serum: Temporary increases in transaminases to twice or three times of the upper limit of normal have been reported by patients at a frequency of 13 - 20 %. In the case of a constant increase in liver-related enzymes, a reduction of the dose or discontinuation of therapy should be taken into consideration.
Due to its potentially toxic effect on the liver, additional hepatotoxic medicinal products should not be taken during treatment with methotrexate unless clearly necessary and the consumption of alcohol should be avoided or greatly reduced. Closer monitoring of liver enzymes should be exercised in patients taking other hepatotoxic medicinal products concomitantly (e.g. leflunomide). The same should be taken into account with the simultaneous administration of haematotoxic medicinal products (e.g. leflunomide).
4. Renal function should be monitored by renal function tests and urinanalysis.
As methotrexate is eliminated mainly by renal route, increased serum concentrations are to be expected in the case of renal impairment, which may result in severe undesirable effects.
Where renal function may be compromised (e.g. in the elderly), monitoring should take place more frequently. This applies in particular when medicinal products are administered concomitantly that affect the elimination of methotrexate, cause kidney damage (e.g. non-steroidal anti-inflammatory medicinal products) or that can potentially lead to impairment of blood formation. Dehydration may also intensify the toxicity of methotrexate.
5. Assessment of respiratory system: Alertness for symptoms of lung function impairment and, if necessary lung function test. Pulmonary affection requires a quick diagnosis and discontinuation of methotrexate. Pulmonary symptoms (especially a dry, non-productive cough) or a non-specific pneumonitis occurring during methotrexate therapy may be indicative of a potentially dangerous lesion and require interruption of treatment and careful investigation. Acute or chronic interstitial pneumonitis, often associated with blood eosinophilia, may occur and deaths have been reported. Although clinically variable, the typical patient with methotrexate-induced lung disease presents with fever, cough, dyspnoea, hypoxemia, and an infiltrate on chest X-ray, infection needs to be excluded. This lesion can occur at all doses.
6. Methotrexate may, due to its effect on the immune system, impair the response to vaccination results and affect the result of immunological tests. Particular caution is also needed in the presence of inactive, chronic infections (e.g. herpes zoster, tuberculosis, hepatitis B or C) for reasons of eventual activation. Vaccination using live vaccines must not be carried out under methotrexate therapy.
Malignant lymphomas may occur in patients receiving low dose methotrexate, in which case therapy must be discontinued. Failure of the lymphoma to show signs of spontaneous regression requires the initiation of cytotoxic therapy.
Concomitant administration of folate antagonists such as trimethoprim/sulphamethoxazole has been reported to cause an acute megaloblastic pancytopenia in rare instances.
Radiation-induced dermatitis and sun-burn can reappear under methotrexate therapy (recall-reaction). Psoriatic lesions can exacerbate during UV-irradiation and simultaneous administration of methotrexate.
Methotrexate elimination is reduced in patients with a third distribution space (ascites, pleural effusions). Such patients require especially careful monitoring for toxicity, and require dose reduction or, in some cases, discontinuation of methotrexate administration. Pleural effusions and ascites should be drained prior to initiation of methotrexate treatment.
Diarrhoea and ulcerative stomatitis can be toxic effects and require interruption of therapy, otherwise haemorrhagic enteritis and death from intestinal perforation may occur.
Vitamin preparations or other products containing folic acid, folinic acid or their derivatives may decrease the effectiveness of methotrexate.
For the treatment of psoriasis, methotrexate should be restricted to severe recalcitrant, disabling psoriasis which is not adequately responsive to other forms of therapy, but only when the diagnosis has been established by biopsy and/or after dermatological consultation.
Encephalopathy / leukoencephalopathy have been reported in oncologic patients receiving methotrexate therapy and cannot be excluded for methotrexate therapy in non-oncologic indications.
The absence of pregnancy should be confirmed before Methotrexate-Teva PEN is administered. Methotrexate causes embryotoxicity, abortion and foetal defects in humans. Methotrexate affects spermatogenesis and oogenesis during the period of its administration which may result in decreased fertility. These effects appear to be reversible on discontinuing therapy. Effective contraception in men and women should be performed during treatment and for at least six months thereafter. The possible risks of effects on reproduction should be discussed with patients of childbearing potential and their partners should be advised appropriately.
Sodium
This medicinal product contains less than 1 mmol sodium (23 mg) per dose, i.e. essentially “sodium-freeâ€.
Paediatric population
Use in children < 3 years of age is not recommended as insufficient data on efficacy and safety is available for this population.
Central nervous symptoms such as tiredness and dizziness can occur during treatment, Methotrexate-Teva PEN has minor or moderate influence on the ability to drive and use machines.
Methotrexate-Teva PEN should only be prescribed by physicians, who are familiar with the various characteristics of the medicinal product and its mode of action. Patients must be educated to use the proper injection technique. The first injection of Methotrexate-Teva PEN should be performed under direct medical supervision. Methotrexate-Teva PEN is injected once weekly.
The patient must be explicitly informed about the fact that Methotrexate-Teva PEN is administered once a week only. It is advisable to determine an appropriate fixed day of the week for the injection.
Methotrexate elimination is reduced in patients with a third distribution space (ascites, pleural effusions). Such patients require especially careful monitoring for toxicity, and require dose reduction or, in some cases, discontinuation of methotrexate administration.
Posology
Dosage in adult patients with rheumatoid arthritis
The recommended initial dose is 7.5 mg of methotrexate once weekly, administered subcutaneously. Depending on the individual activity of the disease and tolerability by the patient, the initial dose may be increased gradually by 2.5 mg per week. A weekly dose of 25 mg should in general not be exceeded. Doses exceeding 20 mg/week are associated with significant increase in toxicity, especially bone marrow suppression. Response to treatment can be expected after approximately 4 - 8 weeks. Upon achieving the therapeutically desired result, the dose should be reduced gradually to the lowest possible effective maintenance dose.
Paediatric population
Dosage in children and adolescents below 16 years with polyarthritic forms of juvenile idiopathic arthritis
The recommended dose is 10 - 15 mg/m² body surface area (BSA)/once weekly. In therapy-refractory cases the weekly dosage may be increased up to 20 mg/m² body surface area/once weekly. However, an increased monitoring frequency is indicated if the dose is increased.
Due to limited data availability about intravenous use in children and adolescents, parenteral administration is limited to subcutaneous injection.
Patients with JIA should always be referred to a rheumatology specialist in the treatment of children/adolescents.
Use in children < 3 years of age is not recommended as insufficient data on efficacy and safety is available for this population.
Dosage in patients with psoriasis vulgaris and psoriatic arthritis
It is recommended that a test dose of 5 - 10 mg should be administered parenterally, one week prior to therapy to detect idiosyncratic adverse reactions. The recommended initial dose is 7.5 mg of methotrexate once weekly, administered subcutaneously. The dose is to be increased gradually but should not, in general, exceed a weekly dose of 25 mg of methotrexate. Doses exceeding 20 mg per week can be associated with significant increase in toxicity, especially bone marrow suppression. Response to treatment can generally be expected after approximately 2 - 6 weeks. Upon achieving the therapeutically desired result, the dose should be reduced gradually to the lowest possible effective maintenance dose.
Maximum weekly dose
The dose should be increased as necessary but should in general not exceed the maximum recommended weekly dose of 25 mg. In a few exceptional cases a higher dose might be clinically justified, but should not exceed a maximum weekly dose of 30 mg of methotrexate as toxicity will markedly increase.
Dosage in patients with Crohn's disease
- Induction treatment:
25 mg/week administered subcutaneously.
Response to treatment can be expected after approximately 8 to 12 weeks.
- Maintenance treatment:
15 mg/week administered subcutaneously.
There is not sufficient experience in the paediatric population to recommend Methotrexate-Teva PEN for the treatment of Crohn's disease in this population.
Patients with renal impairment
Methotrexate-Teva PEN should be used with caution in patients with impaired renal function. The dose should be adjusted as follows:
| Creatinine clearance (ml/min) > 60 30 - 59 < 30 | Dose 100 % 50 % Methotrexate-Teva PEN must not be used |
Patients with hepatic impairment
Methotrexate should be administered with great caution, if at all, to patients with significant current or previous liver disease, especially if due to alcohol. If bilirubin is > 5 mg/dl (85.5 µmol/l), methotrexate is contraindicated.
Use in elderly patients
Dose reduction should be considered in elderly patients due to reduced liver and kidney function as well as lower folate reserves which occur with increased age.
Use in patient with a third distribution space (pleural effusions, ascites)
As the half-life of methotrexate can be prolonged to 4 times the normal length in patients who possess a third distribution space dose reduction or, in some cases, discontinuation of methotrexate administration may be required.
Method of administration
The medicinal product is for single use only.
Methotrexate-Teva PEN solution for injection in pre-filled pen can only be given by subcutaneous route.
The overall duration of the treatment is decided by the physician.
Guidance on how to use Methotrexate-Teva PEN solution for injection in pre-filled pen can be found in section 6.6.
Please note that all of the contents have to be used.
Note:
If changing the oral application to parenteral administration a reduction of the dose may be required due to the variable bioavailability of methotrexate after oral administration.
Folic acid supplementation may be considered according to current treatment guidelines.
The manner of handling and disposal must be in accordance with local requirements. Pregnant health care personnel should not handle and/or administer Methotrexate-Teva PEN.
Methotrexate should not come into contact with the skin or mucosa. In the event of contamination, the affected area must be rinsed immediately with ample amount of water.
For single use only.
Any unused medicinal product or waste should be disposed of in accordance with local requirements.
Instructions for subcutaneous use
The most appropriate zones for the injection are:
- upper thighs,
- abdomen except around the navel.
1. Clean the area around the chosen injection site (e.g. by using the enclosed alcohol pad).
2. Pull the cap straight off.
3. Build a skin fold by gently squeezing the area at the injection site.
4. The fold must be held pinched until the Methotrexate-Teva PEN is removed from the skin after the injection.
5. Push the Methotrexate-Teva PEN firmly into the skin at a 90degree angle in order to unlock the button. Then press the button (a click indicates the start of injection).
6. Do not remove the Methotrexate-Teva PEN from the skin before the end of the injection to avoid incomplete injection. This can take up to 5 seconds.
7. Remove the Methotrexate-Teva PEN from the skin at the same 90degree angle.
8. The protective shield automatically moves into place over the needle and is then locked.
