The degradation of carisoprodol by liver slices was increased by the pretreatments with phenobarbital, phenaglycodol and Doriden. The increase of the enzyme activity began 12 hours after the injection of the inducers and the maximum increase of the enzyme activity (about 2.5-fold) was observed 48 hours after and 96 hours after a little increased activity observed.
In contrast to the increase of enzyme activity the shortened duration of paralysis produced by carisoprodol was observed after the pretreatment with the inducers and also the maximum diminution (about 86%) was found 48 hours after the pretreatments. The induction of the enzyme responsible for metabolism of carisoprodol by the inducers was inhibited by combined injection of ethionine which itself does not affect on the enzyme activity of normal rats.
The higher activity of the hepatic enzyme responsible for carisoprodol metabolism and the higher sensitivity in the induction of the hepatic enzyme to the inducers in immature rats than in young and adult rats were also reported.