Cytochrome P450s and other enzymes in drug metabolism and toxicity

AAPS J. 2006 Mar 10;8(1):E101-11. doi: 10.1208/aapsj080112.

Abstract

The cytochrome P450 (P450) enzymes are the major catalysts involved in the metabolism of drugs. Bioavailability and toxicity are 2 of the most common barriers in drug development today, and P450 and the conjugation enzymes can influence these effects. The toxicity of drugs can be considered in 5 contexts: on-target toxicity, hypersensitivity and immunological reactions, off-target pharmacology, bioactivation to reactive intermediates, and idiosyncratic drug reactions. The chemistry of bioactivation is reasonably well understood, but the mechanisms underlying biological responses are not. In the article we consider what fraction of drug toxicity actually involves metabolism, and we examine how species and human interindividual variations affect pharmacokinetics and toxicity.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cytochrome P-450 Enzyme System / classification
  • Cytochrome P-450 Enzyme System / metabolism*
  • Drug-Related Side Effects and Adverse Reactions / chemically induced
  • Drug-Related Side Effects and Adverse Reactions / metabolism*
  • Humans
  • Pharmaceutical Preparations / chemistry
  • Pharmaceutical Preparations / metabolism
  • Technology, Pharmaceutical / methods*

Substances

  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System