Prolonged hydroxychloroquine use ups risk of retinal toxicity
Long-term use of hydroxychloroquine (HCQ) increases the risk of HCQ retinal toxicity, according to a recent study involving the Korean population. Other risk factors include daily HCQ dose and the presence of kidney disease.
A total of 123 patients who were using or had used HCQ were included in this study that investigated the rate of and factors for HCQ retinal toxicity. Spectral domain optical coherence tomography, fundus autofluorescence, multifocal electroretinography and automated visual field testing were used to diagnose retinal toxicity.
The investigators identified the factors associated with HCQ retinal toxicity by using binary logistic regression analysis.
The mean duration of HCQ use among participants was 10.1 years, while the mean HCQ dose was 6.4 mg/kg. A total of 17 patients (13.8 percent) were found to have HCQ retinal toxicity.
Those with retinal toxicity had prolonged use of HCQ ranging from 6.7 to 21.9 years, with a daily dosage ranging from 4.9 to 9.1 mg/kg. There was only a single patient who had retinal toxicity among those taking a daily dose <5.0 mg/kg.
The following factors increased the risk of HCQ retinal toxicity: longer duration of HCQ use (adjusted odds ratio [aOR], 4.71; 95 percent CI, 2.18 to 10.15 for duration of HCQ use in 5-year increments), higher daily HCQ dose (aOR, 3.34; 1.03 to 10.80 for daily HCQ dose in 100-mg increments) and the presence of kidney disease (aOR, 8.56; 1.15 to 64.00).
“Proper dosing of maximum 5 mg/kg and regular screening according to risk factors are important in HCQ use,” according to researchers.