New guidelines to minimize toxic damage from chloroquine and hydroxychloroquine

The American Academy of Ophthalmology’s recommendations for screening of chloroquine (CQ) and hydroxychloroquine (HCQ) retinopathy were published in 2002. Since then, improved screening tools and new knowledge about the prevalence of toxicity have appeared. This article is an update from the Academy on the latest data and screening recommendations for CQ and HCQ, including risk of toxicity, dosage, screening schedules, and evaluations of the various types of screening tests.

There is still no treatment for this disorder, so it is imperative that patients and their physicians be aware of the best practices for minimizing toxic damage.

• New data have shown that the risk of toxicity increases sharply toward 1 percent after five to seven years of use, or a cumulative dose of 1000 g of HCQ, and the risk increases with continued use of the drug. Previously, dosage was determined by weight. Now a daily dose of 400 mg of HCQ daily (or 250 mg CQ) is considered acceptable, except for individuals of short stature, for whom the dose should be determined on the basis of ideal body weight to avoid overdosage.
• A baseline examination is advised as a reference point and to rule out maculopathy, which might be a contraindication to taking these drugs. Annual screening should begin after five years or sooner if there are unusual risk factors.
• The new guidelines also recommend that in addition to 10-2 automated fields, at least one of the newer objective tests be used, such as multifocal electroretinogram, spectral domain optical coherence tomography or fundus autofluorescence.