Higher hydroxychloroquine dose based on actual body weight is associated with lower SLE flare risks while maintaining...

Area of Science:

• Rheumatology
• Pharmacology

Background:

• The optimal dosage of hydroxychloroquine (HCQ) based on actual body weight (ABW) for treating systemic lupus erythematosus (SLE) is not well-established.
• Understanding the impact of HCQ dosing on SLE patient outcomes is crucial for effective disease management.

Purpose of the Study:

• To investigate the effects of HCQ dose based on ABW in patients diagnosed with SLE.
• To compare the efficacy and safety profiles of high-dose (HD) versus low-dose (LD) HCQ in SLE patients.

Main Methods:

• Patients were categorized into high-dose (≥5 mg/kg ABW) and low-dose (<5 mg/kg ABW) HCQ groups.
• Inverse probability of treatment weighting was used to adjust for patient background characteristics.
• Discontinuation rates, flare rates, prednisolone dosage, and serological data were evaluated in the overall cohort and specific subgroups.

Main Results:

• No significant differences in 5-year discontinuation rates due to adverse events were observed between HD and LD groups (18.9% vs 13.6%).
• Three-year flare-free rates were numerically higher in the HD group compared to the LD group in subgroups with disease duration ≥1 year (75.0% vs 60.7%) and those without additional immunosuppressants (79.2% vs 57.8%).
• In a subgroup analysis, each 0.2 mg/kg increase in HCQ dose was associated with a reduced risk of flares (HR, 0.91; 95% CI: 0.84-0.99).

Conclusions:

• While no definitive differences in efficacy and safety were found between high-dose and low-dose HCQ, a higher HCQ dose correlated with a decreased risk of SLE flares.
• The findings suggest that a lower HCQ dose might be associated with an increased risk of flares in SLE patients.
• This study underscores the importance of considering HCQ dosage relative to ABW in SLE management.