Reference Range of Hydroxychloroquine Blood Levels That Can Reduce Odds of Active Lupus and Prevent Flares

© 2023 The Authors. Arthritis Care & Research published by Wiley Periodicals LLC on behalf of American College of Rheumatology..

OBJECTIVE: Recent data show that lower hydroxychloroquine (HCQ) doses are associated with a two- to six-fold higher risk of lupus flares. Thus, establishing an effective reference range of HCQ blood levels with upper and lower bounds for efficacy may support individualizing HCQ dosing to prevent flares.

METHODS: HCQ levels in whole blood and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) were measured during the baseline visit and again during a standard of care routine follow-up visit. Active cross-sectional lupus at baseline was defined as SLEDAI ≥6; a within subject flare was defined as a subsequent three-point increase in SLEDAI with clinical symptoms requiring therapy change. We examined associations between active lupus and HCQ blood levels at baseline and flares and HCQ levels during 6 to 12-month routine lupus follow-up visits using mixed regression analysis.

RESULTS: Among 158 baseline patient visits, 19% had active lupus. Odds of active lupus were 71% lower in patients with levels within a 750 to 1,200 ng/mL range (adjusted odds ratio 0.29, 95% confidence interval 0.08-0.96). Using convenience sampling strategy during a pandemic, we longitudinally followed 42 patients. Among those patients, 17% flared during their follow-up visit. Maintaining HCQ levels within 750 to 1,200 ng/mL reduced the odds of a flare by 26% over a nine-month median follow-up.

CONCLUSION: An effective reference range of HCQ blood levels, 750 to 1,200 ng/mL, was associated with 71% lower odds of active lupus, and maintaining levels within this range reduced odds of flares by 26%. These findings could guide clinicians to individualize HCQ doses to maintain HCQ levels within this range to maximize efficacy.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:76

Enthalten in:

Arthritis care & research - 76(2024), 2 vom: 04. Feb., Seite 241-250

Sprache:

Englisch

Beteiligte Personen:

Garg, Shivani [VerfasserIn]
Chewning, Betty [VerfasserIn]
Hutson, Paul [VerfasserIn]
Astor, Brad C [VerfasserIn]
Bartels, Christie M [VerfasserIn]

Links:

Volltext

Themen:

4QWG6N8QKH
Antirheumatic Agents
Hydroxychloroquine
Journal Article

Anmerkungen:

Date Completed 01.02.2024

Date Revised 01.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/acr.25228

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM361651384