Immunomodulatory effects of levamisole.

The conditions under which the anthelmintic drug levamisole modulates immune function were reviewed. Treatment with the drug corrects defective leukocyte reactivity and can bring clinical improvement in chronic infections, inflammatory disease, and malignancy. Therapeutic effectiveness depends upon dose, timing, and the patient's immune status, and results are often inconsistent. Levamisole therapy can cause marked but reversible complications, many of which have immunopathologic features.