Hydroxychloroquine Blood Levels May Be Helpful in Patients with “Antimalarial-Resistant” Cutaneous Lupus Erythematosus

Hydroxychloroquine is standard therapy for patients with cutaneous lupus erythematous (CLE), but up to a third of patients appear to be refractory to this agent. Blood levels of hydroxychloroquine are measurable; levels below 750 ng/mL are considered inadequate.

These authors measured blood levels in patients with antimalarial-resistant CLE. Among 74 refractory patients, 36 (49%) had blood levels below 750 ng/mL. Investigators raised the daily hydroxychloroquine dose in 34 of these patients to obtain adequate blood levels, and measured clinical disease using a validated score (CLASI) before and after the intervention. The patients included had a mixture of clinical disease, including discoid LE, subacute CLE, indeterminate disease, chilblain…