Levamisole in rheumatoid arthritis. Final report on a randomised double-blind study comparing a single weekly dose of levamisole with placebo. Multicentre Study Group.

The therapeutic effect of a single weekly dose of levamisole in patients with rheumatoid arthritis was compared with placebo for 6 months in a 13-centre double-blind controlled study. 281 patients with classic or definite rheumatoid arthritis and active disease were evaluated. A single weekly dose of 150 mg levamisole was superior to placebo in controlling disease activity. A single weekly dose of 50 mg levamisole had an intermediate effect. Adverse reactions occurred in approximately 40% of the patients with 150 mg levamisole and in approximately 20% of the patients with 50 mg levamisole or placebo. In comparison with the classical dosage schedule of levamisole (150 mg on 3 consecutive days each week) a single weekly dose of 150 mg levamisole was found to be slightly less effective but much better tolerated.