Hepatic drug-metabolizing enzymes

Hepatic drug-metabolizing enzymes are a heterogeneous group of liver enzymes including cytochrome P450 oxidases, transferases (e.g., UDP-glucuronosyltransferases, glutathione S-transferases), and other oxidoreductases that chemically modify drugs via oxidation, reduction, hydrolysis, and conjugation reactions. These enzymes, mostly concentrated in the smooth endoplasmic reticulum of hepatocytes, play a key role in the metabolic detoxification and excretion of xenobiotics, as well as in the pharmacokinetics of therapeutic agents. The activity and abundance of hepatic drug-metabolizing enzymes influence drug efficacy, toxicity, and interactions, and are genetically and pathologically modulated (notably in liver disease such as hepatitis and cirrhosis). Clinical interventions often target or account for these enzymes to optimize therapy, minimize adverse reactions, and predict patient pharmacokinetics.

Other names

Liver drug-metabolizing enzymesHepatic DMEsLiver CYPsHepatic CYP450 enzymesPhase I/II/III drug-metabolizing enzymes

Substrate (drug metabolized by the enzyme); Inhibitor (drug blocks enzymatic activity, increasing substrate concentration); Inducer (drug increases enzyme expression/activity, lowering substrate concentration)