Background/Purpose:

Hydroxychloroquine is universally recommended to treat patients with SLE, stressing the importance of appropriate dosing. The 2016 American Academy of Ophthalmology (AAO) guidelines recommend a maximum dose of hydroxychloroquine ≤ 5mg/kg/day actual body weight (ABW),¹ which correlates more with retinal toxicity risks than using ideal body weight to calculate dosage. We evaluated the extent of adherence to dosing guidelines by SLE providers to encourage further prospective analysis and intervention to prevent retinal toxicity.

Methods:

Data collected from the Southern California Lupus Registry (SCOLR), an academic single-center cohort of 162 SLE patients, was analyzed. Patients were identified to have SLE by either ACR or 2012 SLICC criteria.^2,3 Chart review identified patients prescribed hydroxychloroquine, dose prescribed, if this dosing was aligned with AAO guidelines, and, if dosed in excess, the amount (in mg) of excess daily hydroxychloroquine.

Results:

Of 162 patients with SLE, 136 received hydroxychloroquine. Fifty-six (41%) of those patients on hydroxychloroquine were on doses exceeding 5mg/kg ABW and eighty (58%) were in line with AAO recommendations. The remaining 26 patients were not on hydroxychloroquine; reasons included adverse reactions or underlying or consequential retinal disease.

Among patients on excessive doses of hydroxychloroquine, the prescribed dose was in excess of recommended dosing by 1.1mg/kg on average (absolute dose 6.1mg/kg). 23 of these patients were dosed greater than 6mg/kg and 6 were receiving doses higher than 7mg/kg.

Conclusion:

Recent uptick in retinopathy in patients on hydroxychloroquine for 5 years or more has reiterated that daily dosing of hydroxychloroquine is the most critical determinant of retinal toxicity risk. This, combined with our findings, implicates the dire need for physicians to appropriately dose hydroxychloroquine in SLE management. We found patients in our cohort dosed in excess as per both 2011 and 2016 American Academy of Ophthalmology Guidelines. This data underscores the importance of reviewing or adjusting hydroxychloroquine doses on regular clinic visits.

Further, while use of weight-based dosing of hydroxychloroquine has demonstrated reduced risk of retinopathy, feasibility of dose adjustments as low as 50 milligrams warrants review of available doses of this medication. Perhaps the availability of 50-100mg dosing will be beneficial in avoiding long term adverse events.

References:

1. Marmor MF, Kellner U, Lai TYY et al. Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016) American Academy Ophthalmology
2. Tan EM, Cohen AS, Fries JF et al. The 1982 revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1982;25:1271-7
3. Hochberg MC, for the Diagnostic and Therapeutic Criteria Committee of the American College of Rheumatology. Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1997;40:1725

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/hydroxychloroquine-do-we-all-see-eye-to-eye-a-single-site-analysis-of-hydroxychloroquine-dosing-compared-to-2016-american-academy-of-ophthalmology-guidelines/