Hydroxychloroquine.

The only antimalarial drug approved by the Food and Drug Administration for the treatment of lupus erythematosus is hydroxychloroquine (Plaquenil) sulfate. The dosage recommended officially for this disease is vague. Retinopathy has been caused by hydroxychloroquine but not in less than six months, nor when a total dosage of less than 72 gm or a daily dose of 200 mg or less is used. The ocular risk depends on the dose/weight ratio and is almost negligible at a dosage of less than 6 mg/kg/day. At a dosage of 400 mg or more daily, the risk/benefit ratio is acceptable for a person of average weight, provided that ophthalmologic monitoring is adequate. Risk of retinal toxicity is then proportional to duration of therapy and consequent cumulative dose. Ophthalmoscopic examinations at six-month intervals should be sufficient to detect occasional adverse reactions. Such tests could be conducted by the attending physician directly, as long as no pre-existing ocular abnormality exists.