Pentobarbital pharmacokinetics in the normal and in the hepatectomized rat

The pharmacokinetics of pentobarbital, a barbiturate metabolized by the liver, was compared in normal and in hepatectomized rats. The blood concentration time curve following a single intravenous injection of pentobarbital was fitted to a two-compartment open model. Both the volume of the central compartment and the elimination rate constant were significantly reduced in hepatectomized rats. It is concluded that the liver plays a role both in the metabolism and the distribution of pentobarbital.