Studies on the Chronic Toxicity of Chloroquine

Ch lo roqu ine, 7-chloro-4(4-diethylamino-lmethylbutylamino) quinoline, is an antimalarial drug of the 4-amino quinoline series. It has been shown to have antimalarial activity similar to and superior to that of quinacrine in avian malaria, and in trophozoiteand sporozoite-induced vivax and falciparum malaria in man ( 1, 2, 3, 4). The present study was undertaken for the purpose of establishing whether chloroquine can be administered for prolonged periods as a suppressive drug without causing serious toxicity. To accentuate toxic manifestations and establish the margin of safety, larger dosages than those necessary for suppressive treatment were administered. Normal inmate volunteers at the Illinois State Penitentiary at Stateville served as subjects for these investigations.