HEPATIC MICROSOMAL-ENZYME INDUCTION AND ITS EVALUATION IN A CLINICAL LABORATORY

  • 1 January 1977
    • journal article
    • research article
    • Vol. 13  (5) , 471-476
Abstract
Whether short-term treatment with .alpha.-methyldopa, quinidine, digoxin, diazepam or furosemide is capable of stimulating activity of hepatic microsomal drug-metabolizing enzymes was examined. Glucaric acid (GA) excretion and serum activity of .gamma.-glutamyl transpeptidase (GGT) were used as indicators of hepatic microsomal enzyme activity. Increased GA excretion was found in 45% and increased serum GGT activity in 40% of patients on drug treatment. Only 14.3% showed an increase in both indicators. Excretion of GA rose significantly in patients who received drugs for more than 10 days as compared with those who received drugs for less than 10 days, whereas percentage of high GGT values did not rise significantly with increased duration of treatment. Lack of correlation between serum GGT activity and GA excretion casts doubt on the value of GGT as a consistent indicator of microsomal enzyme induction. GA excretion seems to be a dependable index of microsomal enzyme induction in response to short-term treatment with standard doses of several widely used drugs.