Clinical pharmacokinetics of remoxipride.

The clinical pharmacokinetics of remoxipride, a pure enantiomer, have been studied in healthy volunteers and patients. After oral administration the drug is rapidly and almost completely absorbed with a bioavailability above 90%. Thus remoxipride is a low clearance drug, with a systemic plasma clearance of about 120 ml/min, and without any first-pass metabolism. The apparent volume of distribution is 0.7 1/kg, about 80% being bound to plasma proteins (mainly alpha 1-acid glycoprotein). Remoxipride has a plasma half-life in the range of 4-7 h and is eliminated by both hepatic metabolism and renal excretion. Slightly more than 70% of the dose is recovered as urinary metabolites and about 25% is excreted unchanged. Steady-state plasma levels are reached within 2 days, and they increase linearly with doses up to 600 mg daily. There is no evidence that active metabolites of remoxipride are present in the blood. Decreased renal function is associated with increased levels of remoxipride, whereas moderate cirrhosis of the liver only slightly affects elimination. There are no pharmacokinetic interactions between remoxipride and diazepam, ethanol, biperiden, or warfarin.