Studies on Chloroquine Retinopathy in Rabbits

CHLOROQUINE PHOSPHATE may induce irreversible retinal pigmentary degeneration in humans who receive the drug in high doses over a long period of time. This report describes ocular changes seen in rabbits after the prolonged oral administration of chloroquine phosphate. MATERIALS AND METHODS Four albino and four pigmented healthy rabbits were fed chloroquine phosphate mixed with their food daily for 11 months. On the basis of a usual human dose of 250 mg/day for a 60-kg human (4.2 mg/k of body weight per day), four animals (two albino and two pigmented) received an approximate daily dosage of 42 mg/day/kg of body weight (ten times the usual human dose), and four animals (two albino and two pigmented) received 21 mg/kg of body weight per day (five times the usual human dose). The dosage for this latter group was later arbitrarily increased fourfold to 84 mg/kg of body weight per day (20 times