Influence of diabetes mellitus on drug metabolism in man.

Drug metabolizing capacity was assessed in 29 normal subjects and in 28 diabetics on various treatment regimes using the rate of antipyrine elimination as reflux. Plasma half-life of antipyrine was markedly shorter (38%), and the plasma clearance of this drug greater (40%) in diabetics receiving insulin than in controls. There was also an indication of a small increase in rate of test drug elimination in diabetics taking chlorpropamide. Patients being controlled solely on diet or those on tolbutamide did not exhibit an altered rate of drug elimination. The rate of metabolism and inactivation of other drugs may be altered in diabetics taking insulin so that optimal doses of some comcomitantly administered drugs may be different in this group of patients.