Methotrexate

Indications & Dose:

Moderate to severe active rheumatoid arthritis;

• BY MOUTH

7.5mg once weekly ( as a single dose or divided into three of 2.5mg given at intervals of 12 hours), adjusted according to response; max. total weekly dose 20mg.

Contraindications:

 Pleural effusion, ascites, hypersensitivity. Severe hepatic or renal impairment, severe anaemia, thrombocytopenia or leucopenia. Pregnancy. Blood count should be monitored.

Side Effects:

 Nausea, vomiting, diarrhea, anaphylaxis, hepatic necrosis, fever, bone marrow depression, osteoporosis, menstrual dysfunction, cirrhosis, pulmonary infiltrates and fibrosis, renal toxicity.

Cautions:

Precautions:

Children, GI disorders, CNS disturbance, hepatic or renal impairment, bone marrow depression. Monitor hepatic, renal and haemato- logical functions.

Breast feeding & old age: Use with caution.

Interaction:

Drugs

Aminoglycosides: Decrease absorption and AUC of oral methotrexate.

Charcoal: Decreases serum level of both oral and i.v methotrexate.

Etretinate: Hepatotoxicity.

Folic acid or its derivatives: Decrease response to methotrexate.

NSAIDs: Increase plasma levels of methotrexate which may be fatal.

Phenytoin: Serum concentration of phenytoin decreased.

Probenecid, Salicylates & Sulfornamides (including Phenylbutazone, Tetracyclines, Chloramphenicol,PABA & TMP-SMZ): Increase in efficacy as well as toxic effects of methrotrexate.

Procarbazine: Increase AUC and plasma levels of thiopurines.

Asparaginase: Reduces toxicity. Food: Reduction in plasma concentration of methotrexate.

Warnings:

Adverse Effects:

Lactations:

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

Patient And Carer Advice: