The influence of selected general anesthetics on pharmacokinetic parameters of some antiarrhythmic drugs in rabbits. Part I. Procainamide and its active metabolite-N-acetylprocainamide.

The influence of general anesthesia with thiopental (10 mg/kg), ketamine (4 mg/kg), propofol (10 mg/kg) or pentobarbital (20 mg/kg) on the pharmacokinetics of procainamide (13 mg/kg) and its active metabolite-N-acetylprocainamide was studied in rabbits. The general anesthesia with those drugs caused only the slight changes in procainamide pharmacokinetics, namely changing volume of distribution, penetration rate constants between central and peripheral compartments. However, the following main changes in N-acetylprocainamide (metabolite) pharmacokinetic parameters were found: 1) increase of the penetration rate constants between the compartments and mean residence time during propofol anesthesia 2) prolongation of the mean residence time during thiopental anesthesia 3) increase of mean residence time of N-acetylprocainamide during anesthesia with ketamine, pentobarbital or propofol.