Low-dose hydroxychloroquine use for long-term tied to low retinopathy risk: Study

USA: A recent study published in the Annals of Internal Medicine has found that patients who received hydroxychloroquine for five or more years with guideline-recommended serial retinopathy screening had a low overall risk for incident retinopathy, with most documented cases being mild. Higher hydroxychloroquine dose was linked with progressively greater risk. 

"In the large, contemporary cohort of more than 3,000 people with active surveillance retinopathy screening, the overall risk for hydroxychloroquine retinopathy was 8.6% after 15 years, and the majority of cases were mild," the researchers wrote in their study. "Higher hydroxychloroquine dose was tied to progressively higher risk for incident retinopathy

Hydroxychloroquine is recommended for patients with systemic lupus erythematosus and other inflammatory conditions, but vision-threatening retinopathy is serious long-term adverse effects. Guidelines recommend dosing at 5 mg/kg of body weight per day or lower. However, available study evidence supporting this is relatively weak.

Researchers from Kaiser Permanente Northern California and Harvard Medical School studied 3,325 persons who received hydroxychloroquine for five or more years between 2004 and 2020 to characterize the long-term risk for incident hydroxychloroquine retinopathy and examine the degree to which average hydroxychloroquine dose within the first five years of treatment predicts this risk. The researchers used pharmacy and health records to analyze hydroxychloroquine dosing and reviewed annual optical scans to determine if there was evidence of retinopathy. If retinopathy cases were identified, they were classified as mild, moderate, or severe.

The researchers then estimated the risk of developing retinopathy after 15 years according to average dosing levels during the first five years. They found that 81 participants developed hydroxychloroquine retinopathy with overall cumulative incidences of 2.5 and 8.6 percent occurring after 10 and 15 years, respectively, with the risk being greater for those given a higher dose during the first five years of treatment. The researchers note that regular screening can identify this issue at an early and treatable stage.

Reference:

Ronald B. Melles, April M. Jorge, Michael F. Marmor,  Baijun Zhou, Carol Conell, Jingbo Niu, Natalie McCormick, Yuqing Zhang and Hyon K. Choi,  https://doi.org/10.7326/M22-2453