Levamisole in Crohn's disease: a randomized, double-blind, placebo-controlled clinical trial.

To evaluate the efficacy of levamisole in the treatment of Crohn's disease, 19 patients were entered into a long-term, randomized, double-blind, placebo-controlled clinical trial. Seventeen patients (eight in the levamisole group and nine in the placebo group) completed the initial treatment arm of the study. Assessments made at 4- and 12-month intervals failed to show any statistically significant difference between the two groups. Sixteen patients embarked on the second segment of the study; six were continued on the same initial therapy while the remaining 10 were crossed over to the alternate treatment. Again, analysis of the clinical scores did not reveal any beneficial effect of levamisole; in fact, all three patients who remained on levamisole for a period of 12 months after cross-over showed deterioration. The overall dismal results have provided no basis for enthusiasm for levamisole in the treatment of Crohn's disease.