Chloroquine retinopathy: is there a safe daily dose?

Published case reports of chloroquine retinopathy rarely include details of daily dosage, but 30 reports where this information was available included 78 patients who developed impaired visual acuity an 13 had received daily doses of 250 mg or less. Eleven cases of ocular toxicity attributed to chloroquine were reported to the Committee on Safety of Medicines but only 2 developed impaired vision on 250 mg daily. A postal questionnaire among 41 rheumatology and 33 ophthalmology centres showed 2 patients who developed impaired vision as a result of treatment with chloroquine in a daily dose not exceeding 250 mg. Serious visual impairment related to chloroquine rarely occurs if the daily dose does not exceed 250 mg.