Methotrexate for psoriasis: 1981.

Although not stated in body of this article, it is best to start treatment with a very small test dose. Furthermore, one should use methotrexate only when other methods fail or are impractical. In general, the criterion of life-ruining disease should be considered the primary indication. Drugs interactions should be avoided. Probenecid, phenylbutazone, and colchicine are contraindicated. Increased toxicity may occur with concomitant use of salicylates, sulfonamides, barbiturates, para-aminobenzoic acid, diphenylhydantoin, oral contraceptives, and weak organic acids. It would appear at this time that any dose being administered more often than once weekly is too toxic for the liver. Perhaps the intramuscular route is safest. Finally, the official guidelines should be followed as closely as possible, even possibly including liver biopsies. It should be recognized that liver biopsy is not without hazard, as deaths have been reported from simple needle liver biopsies.