Influence of Kidney Function on Serum Risperidone Concentrations in Patients Treated With Risperidone

Area of Science:

• Pharmacology
• Nephrology
• Psychiatry

Background:

• Risperidone is a widely prescribed antipsychotic medication.
• Its primary metabolite, 9-hydroxyrisperidone (9-OH-RIS), is eliminated by the kidneys.
• The impact of renal function on risperidone serum levels requires investigation.

Purpose of the Study:

• To investigate the relationship between kidney function and serum concentrations of risperidone and its active metabolite.
• To determine if estimated glomerular filtration rate (eGFR) influences risperidone and 9-OH-RIS levels.
• To provide evidence-based recommendations for risperidone dosing in patients with impaired renal function.

Main Methods:

• Serum concentrations of risperidone, 9-OH-RIS, and creatinine were measured in 175 patients.
• Glomerular filtration rates (GFRs) were estimated from creatinine levels.
• Patients were stratified into four groups based on eGFR, and drug concentrations were compared.

Main Results:

• Dose-corrected concentrations of 9-OH-RIS and the active moiety (AM) were significantly higher in patients with eGFR between 30-60 mL/min/1.73 m² compared to those with higher eGFR.
• Dose-corrected AM levels were more than doubled in the lowest eGFR group.
• A weak but significant negative correlation was observed between eGFR and dose-corrected 9-OH-RIS and AM concentrations.

Conclusions:

• Kidney function is a critical factor influencing risperidone clearance.
• Elevated serum concentrations of risperidone and 9-OH-RIS occur in patients with reduced renal function.
• A 50% reduction in risperidone dosage is suggested for patients with a GFR below 60 mL/min.