Pharmacokinetics of metapramine (19560 RP) in man after infusion and intravenous injection.

The time course of the plasma level metapramine following infusion at three different rates (1.18, 2.36 and 4.71 mg/h) has been studied in six healthy volunteers. The correlation coefficient of drug concentration and rate of infusion was 0.974 (alpha less than 0.001, n = 18). Plasma clearance, estimated from the steady-state level, varied from 68 to 1071/h. 3 subjects also received 35 mg of drug by i.v. bolus injection and plasma concentrations were determined at set times for up to 24 h. The plasma level of metapramine decreased tri-exponentially, with a terminal half-life of about 7.4 h. The plasma clearance after i.v. injection was in good agreement with that observed during the infusion study. Apparent volumes of distribution ranged from 41.9 to 90.31.