Hydroxychloroquine non-adherence linked to increased risks of flares, mortality in SLE

Severe non-adherence to hydroxychloroquine (HCQ) is independently associated with the risks of an systemic lupus erythematosus (SLE) flare in the following year, early damage, and 5-year mortality, according to a study.

In the study, which included 660 patients, severe non-adherence was determined by measuring serum HCQ levels, with levels falling below 106 ng/ml or 53 ng/ml for HCQ doses of 400 mg/d or 200 mg/d, respectively. Out of the 660 patients included in the study, 7.3% (48 patients) exhibited severe non-adherence to HCQ treatment.

The researchers did not find any significant covariates associated with severe non-adherence, indicating that adherence issues were not limited to any specific demographic or medical factors. However, the study results found that severe non-adherence was independently associated with a substantially increased risk of SLE flares in the following year, as well as an accelerated increase in the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) within the first 3 years (HR 1.92 at 3 years; 95% CI 1.05-3.50).

Patients who exhibited severe non-adherence faced a 5-fold increase in mortality risk within the 5-year study period, with 3 out of the 11 recorded deaths attributed to severe HCQ non-adherence (crude HR 5.41; 95% CI 1.43-20.39).

Reference
Nguyen Y, Blanchet B, Urowitz MB, et al. Association between severe non-adherence to hydroxychloroquine and SLE flares, damage, and mortality in 660 patients from the SLICC Inception Cohort. Arthritis Rheumatol. 2023;doi: 10.1002/art.42645. Epub ahead of print. PMID: 37459273.