[Immunopharmacology of levamisole]

Levamisole, a simple chemical, first introduced as a broad spectrum anthelmintic, is an immunotherapeutic agent with anti-anergic properties. It is the first member of a potential new class of immunologically active, probably thymomimetic compounds. The present knowledge from studies on isolated cells, experimental animals, healthy volunteers and patients with various diseases shows that levamisole behaves physiologically as a thymus hormone and restores to normal the functions of phagocytes and T-lymphocytes in compromised hosts and induces T-cell differentiation. The biochemical mechanism of action remains still unclear. The various mechanisms by which levamisole might act are not mutually exclusive. Levamisole is well tolerated in doses of 2,5 mg/kg. Side-effects are markedly more frequent in patients with rheumatoid arthritis than with other diseases. The only potentially fatal adverse reaction is agranulocytosis.