Drug Metabolism in the Liver

Clin Liver Dis. 2017 Feb;21(1):1-20. doi: 10.1016/j.cld.2016.08.001. Epub 2016 Oct 15.


Metabolism is a biotransformation process, where endogenous and exogenous compounds are converted to more polar products to facilitate their elimination from the body. The process of metabolism is divided into 3 phases. Phase I metabolism involves functionalization reactions. Phase II drug metabolism is a conjugation reaction. Phase III refers to transporter-mediated elimination of drug and/or metabolites from body normally via liver, gut, kidney, or lung. This review presents basic information on drug-metabolizing enzymes and potential factors that might affect the metabolic capacities of the enzyme or alter drug response or drug-mediated toxicities.

Keywords: Conjugation; Cytochrome P450; Drug metabolism; Drug transporters; Liver metabolism; Phase I, II, and III metabolism enzyme.

Publication types

  • Review

MeSH terms

  • Biological Transport / physiology
  • Biotransformation*
  • Cytochrome P-450 Enzyme System / metabolism*
  • Humans
  • Liver / enzymology*
  • Liver / metabolism*
  • Pharmaceutical Preparations / administration & dosage
  • Pharmaceutical Preparations / metabolism*


  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System