Hydroxychloroquine Dose and Hospitalizations for Active Lupus

Area of Science:

• Rheumatology
• Clinical Pharmacology

Background:

• Systemic lupus erythematosus (SLE) is a chronic autoimmune disease.
• Hydroxychloroquine (HCQ) is a common treatment for SLE, but optimal dosing strategies require further investigation.
• Understanding HCQ dosage impact on SLE flares is critical for patient outcomes.

Purpose of the Study:

• To evaluate the association between hydroxychloroquine (HCQ) dosage and the risk of hospitalizations for active systemic lupus erythematosus (SLE).

Main Methods:

• A case-crossover study design was employed, analyzing data from patients with SLE between 2011 and 2021.
• HCQ doses were categorized by weight-based (≤5 vs >5 mg/kg/day) and non-weight-based (<400 vs 400 mg/day) metrics.
• Conditional logistic regression was used to calculate adjusted odds ratios (ORs) for SLE hospitalizations.

Main Results:

• Lower weight-based HCQ doses (≤5 mg/kg/day) were associated with a 4.20-fold increased risk of SLE hospitalizations.
• Lower non-weight-based HCQ doses (<400 mg/day) showed a 3.39-fold increased risk of SLE hospitalizations.
• These associations remained significant after adjusting for covariates.

Conclusions:

• Lower hydroxychloroquine (HCQ) doses are linked to a higher risk of hospitalizations for active systemic lupus erythematosus (SLE).
• The potential for HCQ-induced retinopathy must be weighed against the increased short-term and cumulative risks of SLE disease activity.
• Optimizing HCQ dosage is essential for managing SLE and preventing severe disease flares.