November 13, 2022
3 min read
Nestor J. Abstract 1654. Presented at: ACR Convergence 2022; Nov. 11-14, 2021; Philadelphia (hybrid meeting).
Nestor reports no relevant financial disclosures.
PHILADELPHIA — In patients with systemic lupus erythematosus, lower doses of hydroxychloroquine increase the risk for hospitalization due to flare, according to data presented at ACR Convergence 2022.
The researchers concluded that these findings should prompt experts to reconsider the current weight-based hydroxychloroquine dosing guidelines, which have resulted in some patients with SLE receiving less than 400 mg per day.
“Unfortunately, despite all of the benefits [of hydroxychloroquine in lupus], there is a side effect that we do have to be concerned about, which is hydroxychloroquine-induced retinopathy that leads to vision loss,” Jacquelyn Nestor, MD, PhD, a clinical and research rheumatology fellow at Massachusetts General Hospital, said during a press conference. “Because of this, we as rheumatologists have our patients who are on hydroxychloroquine see the ophthalmologist once a year in order to monitor for this side effect.
“Given the concern for vision loss, in 2011 the American Academy of Ophthalmology recommended guidelines where the hydroxychloroquine dosing was limited to less than 6.5 mg per kg per day of ideal body weight,” she added. “These guidelines were further progressed in 2016, when they reduced the dosing again to less than 5 mg per kg per day. Prior to these guidelines, most lupus patients had been on a baseline dose of 400 mg per day. Given that most lupus patients weigh less than 80 kg, these new guidelines did lead to a dose reduction to below 400 mg for many of our patients.”
To examine the impact of hydroxychloroquine dosing on the risk for hospitalization due to flare in SLE, Nestor and colleagues conducted a case-crossover study within the Mass General Brigham SLE cohort, which includes patients from Massachusetts General Hospital and Brigham and Women’s Hospital. Using an EHR-based algorithm, the researchers included patients with SLE who had at least one visit for SLE, and were prescribed hydroxychloroquine, between January 2011 and December 2021.
Among these patients, the researchers identified those who were hospitalized during this period with SLE as the primary discharge diagnosis code. They then reviewed each hospitalization record and excluded those with non-SLE indications. Patients with at least one hospitalization for SLE flare while being treated with hydroxychloroquine were included in the case-crossover study. The researchers defined case periods as 6 months prior to a hospitalization for SLE flare. Control periods were non-overlapping 6-month periods without a hospitalization; periods without any hydroxychloroquine use were excluded.
Included patients could demonstrate up to three case periods and three control periods. The researchers examined average weight-based hydroxychloroquine dose, categorized as either 5 mg or less per kg per day, or greater than 5 mg per kg per day, as well as the average non-weight-based dose, defined as 400 mg per day or less, assessed during each 6-month case or control period. ORs were assessed using conditional logistic regression and adjusted for SLEDAI, glucocorticoid use and other immunosuppressant use, all assessed at the most recent outpatient visit prior to each 6-month period.
According to the researchers, among the 2,971 patients with SLE who received hydroxychloroquine, 576 demonstrated at least one hospitalization with a primary discharge diagnosis of SLE. Of these cases, 108 were hospitalized for SLE flare while using hydroxychloroquine and demonstrated at least one control period with the drug. Low-dose hydroxychloroquine, administered either by weight-based (adjusted OR = 4.41; 95% CI, 1.5-12.98) or by non-weight-based (aOR = 3.48; 95% CI, 1.33-9.13) regimens, was associated with increased hospitalizations for SLE.
“The results of our study suggest that maybe we need to re-evaluate these current dosing guidelines for hydroxychloroquine, as they are the same for all lupus patients regardless of their disease activity or their stage in the disease itself,” Nestor said. “Currently, we are protecting our patients against a very long-term side effect of hydroxychloroquine — retinopathy typically takes 10 to 20 years to develop in our patients.
“However, by doing that we are missing many of the short-term benefits from hydroxychloroquine, leading to more lupus flares, which lead to more end-organ damage and ultimately more exposures to other immunosuppressants, which have their own host of side effects,” she added. “Based on the results of this study, we would propose possibly considering whether patients earlier in their disease need a higher dose of hydroxychloroquine, or whether those patients with particularly active lupus need the higher doses. Regardless, it needs to be something that could be re-evaluated by rheumatologists and ophthalmologists together.”