Abstract
Purpose :
To characterize the prevalence of excessively dosed hydroxychloroquine prescription practices with regard to ophthalmic safety, based on the 2016 Academy of Ophthalmology revised recommendations of a maximum daily dose of ≤5 mg/kg of actual body weight.
Methods :
A retrospective chart review was performed of hydroxychloroquine prescriptions from January 1, 2018 to December 31, 2018 at a tertiary medical center. Inclusion criteria were age ≥18 years and availability of dose and patient weight data. The mean daily dose and prevalence of excessive dosing were calculated. T-test, chi-squared test, and logistic regression were used to compare demographic and clinical characteristics between safe versus excessive dosing subgroups. Bonferroni correction was applied in cases of multiple comparisons.
Results :
There were 6717 active prescriptions of hydroxychloroquine with dose information available. Those without patient weight were excluded, resulting in a final sample of 6581 (98%) patients. The mean age was 55.9±15.4 years, and 83% were women. The racial background was 78% Caucasian, 19% African American, 1% Asian, and 2% other. The prescribing specialty was primary care 13%, rheumatology 76%, pulmonology 4%, dermatology 2%, and other specialty 5%. The mean hydroxychloroquine daily dose was 342±94 mg daily (4.3±1.4 mg/kg/day), and mean duration of use was 2.9±3.7 years.
The prevalence of excess dosing was 28%. The mean daily dose among excessively dosed patients was 401±55 mg (6.0±1.0 mg/kg/day). Patients who were excessively dosed had lower mean weight (67.2±9.6 vs 88.7±23.2 kg, P<0.001) and longer mean duration of use (3.0±3.8 vs 2.8±3.7 years, P=0.012) compared to those who were not. Caucasians were more likely than African Americans to be excessively dosed (OR 1.38, 95% CI: 1.19-1.59, P<0.001). There was a higher proportion of women among those who were excessively dosed compared to those who were not (87% vs 82%, P<0.001). There were no differences in age or prescribing specialty between patients with ophthalmic safe versus excess weight-based dosing.
Conclusions :
Excessive dosing of hydroxychloroquine has a 28% prevalence and is associated with lower body weight and female sex. Caucasians were more likely than African Americans to be excessively dosed. Patients who are excessively dosed tended to have longer duration of hydroxychloroquine use, compounding higher cumulative drug exposure and risk of retinal toxicity.
This is a 2020 ARVO Annual Meeting abstract.