Methotrexat Ebewe Special Precautions

Methotrexate may only be administered under the supervision of a physician qualified in oncology with experience in the use of antineoplastic chemotherapy.
Methotrexate should be used with extreme caution in patients with haematological depression, renal impairment, peptic ulcer, ulcerative colitis, ulcerative stomatitis, diarrhoea debility and in young children and the elderly.
Patients with pleural effusions or ascites should have these drained if appropriate before treatment or treatment should be withdrawn.
Symptoms of gastro-intestinal toxicity, usually first manifested by stomatitis, indicate interruption of therapy otherwise haemorrhagic enteritis and death from intestinal perforation may occur if the treatment is continued.
Methotrexate may cause decreased fertility, oligospermia, menstrual dysfunction and amenorrhoea. This effect appears to be reversible on discontinuing therapy. Beyond this methotrexate causes embryo toxicity and foetal defects and may cause abortion. If one of the partners is being treated with methotrexate, conception should be avoided during treatment and at least three months after cessation of treatment.
Before beginning methotrexate therapy or reinstituting methotrexate after a rest period, assessment of renal function, liver function and blood elements should be made by history, physical examination and laboratory tests. 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.
It is essential that the following laboratory tests are included regularly in the clinical evaluation and monitoring of patients receiving methotrexate: complete haematological analysis, urinalysis, renal function tests, liver function tests and when high doses are administered, determination of plasma levels of methotrexate.
Particular attention should be given to the appearance of liver toxicity which may occur without correlative changes in liver function tests. Treatment should not be instituted or should be discontinued if any abnormality in 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.
When to perform a liver biopsy in rheumatoid arthritis patients has not been established either in terms of a cumulative methotrexate dose or duration of therapy.
Pleuropulmonary manifestation of rheumatoid arthritis have been reported in the literature. In patients with rheumatoid arthritis, the physician should be specifically alerted to the potential for methotrexate induced adverse effects in the pulmonary system. Patients should be advised to contact their physicians immediately should they develop a cough or dyspnoea.
Haemopoietic suppression caused by methotrexate may occur abruptly and with apparently safe dosages. Any profound drop in white-cell or platelet counts indicate immediate withdrawal of the drug and appropriate supportive therapy.
High doses may cause the precipitation of methotrexate or its metabolites in the renal tubules. A high fluid throughput and alkalinisation of the urine to pH 6.5-7.0 by oral or intravenous administration of sodium bicarbonate (5 x 625mg tablets every three hours) or acetazolamide (500mg orally four times a day) is recommended as a preventive measure.
The Rules of the National Working Environment Authority concerning handling of cytostatics should be followed.
Effects on ability to drive and use machines: Depending on individual susceptibility, the patient's ability to drive a vehicle or operate machinery may be impaired.