[Hydroxychloroquine in systemic lupus erythematosus: Key updates].

Area of Science:

• Rheumatology
• Ophthalmology
• Pharmacology

Context:

• Hydroxychloroquine (HCQ) is a foundational therapy for systemic lupus erythematosus (SLE).
• Recent guidelines (EULAR 2023, KDIGO 2024) emphasize precise dosing (5mg/kg/day) and monitoring for toxicity.
• Understanding HCQ's benefits, risks, and adherence factors is critical for effective SLE management.

Purpose:

• To summarize current evidence on hydroxychloroquine (HCQ) in SLE management.
• To highlight updated guidelines on HCQ dosage, toxicity, and monitoring.
• To underscore the importance of adherence and screening for optimizing patient outcomes.

Summary:

• Reducing HCQ dose below 5mg/kg/day increases flare and hospitalization risk.
• HCQ retinopathy prevalence is 8.6-11.5% after 15 years; risk factors include dose, duration, renal impairment, and specific patient characteristics.
• Annual ophthalmologic screening is recommended after five years; HCQ withdrawal significantly raises relapse risk.
• Poor adherence is indicated by HCQ levels <200ng/mL.
• HCQ is safe in pregnancy and reduces cardiovascular event risk in SLE patients.

Impact:

• Optimized HCQ dosing and adherence can mitigate SLE flares and hospitalizations.
• Proactive ophthalmologic screening can prevent HCQ-related retinopathy.
• Continued HCQ use is associated with reduced cardiovascular risk in SLE.
• This evidence reinforces HCQ's essential role in SLE, guiding clinical practice for improved patient care.