Studies on the Pharmacology of Chloroquine

Abstract

Introduction Chloroquine (7-chloro-4- (4-diethylamino1-methylbutylamino) quinoline (Fig 1) was originally developed as an antimalarial agent. In recent years it has been found to be beneficial in a variety of diseases, including rheumatoid arthritis, discoid and systemic lupus erythematosus. When used as a malarial suppressive, 500 mg of chloroquine salt are given once a week. In the treatment of diseases other than malaria, chloroquine is administered in a much larger dosage and more frequently, usually 250 to 750 mg daily.¹ The occurrence of a characteristic retinopathy following the long-term daily ad- ministration of chloroquine has now been well documented.²The fact that the retinal lesion usually develops after one or more years of drug ingestion, plus the remarkably large accumulation of chloroquine in body tissues and organs,^3-5suggests that the retinopathy may be due to high chloroquine levels in the ocular tissues. The present report concerns the finding of