The clinical pharmacokinetics of buflomedil in normal subjects after intravenous and oral administration.

A dose-ranging pharmacokinetic study of buflomedil was carried out in eight subjects to determine the pharmacokinetic parameters of the drug after oral and intravenous administration. Based on AUC infinity analyses, the pharmacokinetics of buflomedil were found to be linear within the dose ranges studied (50 to 200 mg for i. v. injection and 150 to 450 mg for oral administration). In the oral study, the mean biological half-life of the drug was 2.97 h, while after intravenous dose it was 3.25 h. The apparent volume of distribution after the pseudodistribution equilibrium (Fd beta) and volume of distribution at the steady state (Vdss) were 1.43 +/- 0.24 l/kg and 1.32 +/- 0.26 l/kg, respectively. The mean urinary recovery of intact drug and the metabolite, paradesmethyl buflomedil, after intravenous dosing, were 23.6% and 18.7%, respectively, while after oral dosing, they were 18% and 14.8%, respectively. On the average, 72% of the dose was observed into the systemic circulation after oral administration. This level of bioavailability was attributed to the hepatic first-pass effect.