Complications of cancer immunotherapy with levamisole.

In a group of 69 patients receiving levamisole the drug had to be discontinued in 15 (21-7%) because of intolerable but reversible side-effects including gastrointestinal upset, "flu-like" syndrome, central nervous system disturbances, and skin rash. Reversible agranulocytosis with life-threatening sepsis occurred in a patient receiving levamisole immunotherapy for colonic carcinoma. Neutrophils and platelets were both severely affected. Levamisole-dependent leucoagglutinins appeared with circulating immune complexes during the acute phase of the illness, suggesting an immune drug reaction.