KAUAI, HAWAII – Dermatologists don’t ordinarily peruse the ophthalmology literature. So they may be unaware that the American Academy of Ophthalmology has issued Erik J. Stratman, MD, noted at the Hawaii Dermatology Seminar provided by Global Academy for Medical Education/Skin Disease Education Foundation.
Most dermatologists routinely dose hydroxychloroquine at 400 mg/day, regardless of body weight. The former AAO recommendation, which dates back to 2011, called for dosing at up to 6.5 mg/kg of ideal body weight or 400 mg/day, whichever is lower. However, the AAO recommendation has changed in light of a large, retrospective case-control study that suggested this practice may be overdosing thin patients – thereby exposing them to increased risk of retinal toxicity and other drug-related adverse events – while at the same time possibly underdosing some obese patients, said
This was one of two dermatology practice gaps he highlighted involving suboptimal medication management, the other being most dermatologists’ failure to protect their patients’ gut when prescribing prednisone.
“I think the push over the last 5 years has been ‘protect the bones, protect the bones, protect the bones.’ We’ve done better and better about protecting the bones and getting that into our conversations with patients on prednisone. But we’re not thinking so much about the gut,” the dermatologist said.
The former AAO recommendation was revised in response to a retrospective case-control study of retinal toxicity rates in 2,361 patients on the drug continuously for longer than 5 years. The study demonstrated that the risk of retinopathy jumped 5.7-fold with daily consumption of hydroxychloroquine at more than 5.0 mg/kg ().
The current AAO recommendation () is to dose hydroxychloroquine at a daily maximum of 5.0 mg/kg of real weight, which correlated better with retinopathy risk in the case-control study than did ideal body weight. Hydroxychloroquine doesn’t accumulate well in fat.
Until now, most dermatologists have not routinely measured patients’ body weight in the office or calculated their body mass index. But Dr. Stratman advised against reliance upon a patient’s self-reported body weight, which may diverge substantially from reality. “Get yourself a good office scale – they’re not that expensive – and use it when prescribing drugs with a tight therapeutic window,” he urged.