Pharmacokinetics of sulpiride after intravenous administration in patients with impaired renal function

Single intravenous doses of sulpiride 100 mg were administered to 18 patients with renal function impairment, and 6 healthy volunteers. The plasma concentration-time profile is described by a 2-compartment open model. The differences between the pharmacokinetic parameters of sulpiride for the 2 groups were statistically significant. Elimination half-life, mean residence time and area under the plasma concentration-time curve are significantly greater in renal failure; renal and total clearance, and the cumulative amount of unchanged sulpiride in urine, are significantly reduced but volume of distribution remains unchanged. Creatinine clearance was strongly correlated with renal clearance of sulpiride, elimination rate constant, area under the curve and cumulative amount excreted in urine. For patients with impaired or physiologically reduced renal function receiving long term sulpiride treatment, a 35 to 70% reduction in dose, or extension of the dosage interval by a factor of 1.5 to 3, may be required.