Metabolic degradation of propanidid by various tissues. Short communication

The very short anaesthetic action of 3-methoxy-4-(N,N-diethylcarbamoyl-methoxy)-phenylacetic acid propylester (propanidid, Epantol) is due to its rapid hydrolysis in vivo. In this study, the rates of degradation of this drug under the influence of various isolated tissues have been established. The drug was hydrolysed much more rapidly by liver homogenate than by whole blood or serum. It is concluded that inactivation of propanidid in vivo occurs mainly by the liver, whereas blood esterases play an insignificant part in hydrolyzing the ester. Moreover, it was demonstrated that cardiac tissue is able to hydrolyze the drug as well. It is postulated that the inactivation of propanidid by heart muscle might partly compensate for the severe cardiodepressive action of the anaesthetic agent. A gaschromatographic determination of propanidid has been developed.