Methotrexate side‐effects

SUMMARY Methotrexate is by far the most widely used cytotoxic drug in psoriasis. Treatment requires normal kidney, liver and bone‐marrow function, and pregnancy and alcohol abuse are absolute contraindications. Serious toxic reactions are recognized, but can be avoided if the drug is used correctly. The most important side‐effects are haematopoietic and hepatotoxic. It is well established that long‐term methotrexate can induce liver damage which, in a number of patients, may lead to fibrosis or cirrhosis. Recent studies have, however, documented that the methotrexate‐induced liver cirrhosis is not aggressive. Interaction can occur with a number of drugs; serious problems in particular may arise with concomitant use of sulphonamides and salicylates. The recommended guidelines for methotrexate use in psoriasis should be followed and patients given clear instructions.