The non-hematological side effects of levamisole in the treatment of rheumatoid arthritis--a review.

The non-hematological side effects of levamisole include (1) sensorineural reactions, the most common of which is alterating of taste and smell; (2) idiosyncratic or allergic reactions such as rash and a febrile, influenza-like illness; and (3) gastro-intestinal symptoms. The sensorineural reactions are seldom of sufficient severity to require discontinuation of treatment. Rash and febrile illness have resulted in withdrawal of levamisole in 7% and 1.5% of cases, respectively, but usually remit spontaneously within a brief interval and are not hazardous except when associated with agranulocytosis. Rash due to levamisole occurs more frequently in rheumatic disease patients than in other conditions. Gastro-intestinal symptoms are mild, quickly reversible, and possibly dose-related; some controlled trails have shown a similar frequency of gastro-intestinal symptoms in the placebo group.