Nonadherence to hydroxychloroquine seen in 15% of SLE patients

SAN DIEGO — Fifteen percent of patients with systemic lupus erythematosus had complete nonadherence to hydroxychloroquine therapy, while a larger percentage of patients had only partial adherence, according to research presented at the American College of Rheumatology annual meeting.

Michelle Petri, MD, MPH, professor of medicine and director of the Lupus Center, Johns Hopkins University School of Medicine, and colleagues measured hydroxychloroquine blood levels of 552 patients with systemic lupus erythematosus (SLE; mean age, 46 years; 93% women).

Eighty-four patients (15%) had a 0 level, indicating complete nonadherence; 186 patients (34%) had levels between 15-500 ng/mL, or partial adherence; 249 (45%) had therapeutic levels of 500 to 1,500 ng/mL; and 33 (6%) recorded supratherapeutic levels.

“This is very important information for clinicians because we are depending on hydroxychloroquine to prevent most of the long-term complications of lupus, including organ damage and thrombosis,” Petri told

Patients improved their hydroxychloroquine levels in their second visits, Petri said, showing that discussing adherence can educate patients and improve behaviors.

Disclosure: Petri has conducted research for Human Genome Sciences/GlaxoSmithKline, Medimmune, Pfizer, Teva, Anthera and UCB, and has served as a consultant for Genentech, Lilly and Merck Serono.

For more information:

Petri M. #1805: Hydroxychloroquine Levels Identify Four Distinct Subsets of Systemic Lupus Erythematosus Patients. Presented at: the 2013 American College of Rheumatology Annual Meeting; Oct. 26-30, San Diego.

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