The effect of cytochrome P450 metabolism on drug response, interactions, and adverse effects

Am Fam Physician. 2007 Aug 1;76(3):391-6.

Abstract

Cytochrome P450 enzymes are essential for the metabolism of many medications. Although this class has more than 50 enzymes, six of them metabolize 90 percent of drugs, with the two most significant enzymes being CYP3A4 and CYP2D6. Genetic variability (polymorphism) in these enzymes may influence a patient's response to commonly prescribed drug classes, including beta blockers and antidepressants. Cytochrome P450 enzymes can be inhibited or induced by drugs, resulting in clinically significant drug-drug interactions that can cause unanticipated adverse reactions or therapeutic failures. Interactions with warfarin, antidepressants, antiepileptic drugs, and statins often involve the cytochrome P450 enzymes. Knowledge of the most important drugs metabolized by cytochrome P450 enzymes, as well as the most potent inhibiting and inducing drugs, can help minimize the possibility of adverse drug reactions and interactions. Although genotype tests can determine if a patient has a specific enzyme polymorphism, it has not been determined if routine use of these tests will improve outcomes.

Publication types

  • Review

MeSH terms

  • Cytochrome P-450 Enzyme Inhibitors
  • Cytochrome P-450 Enzyme System / genetics
  • Cytochrome P-450 Enzyme System / metabolism*
  • Drug Interactions*
  • Drug-Related Side Effects and Adverse Reactions
  • Genotype
  • Humans
  • Pharmaceutical Preparations / metabolism*
  • Pharmacogenetics
  • Polymorphism, Genetic

Substances

  • Cytochrome P-450 Enzyme Inhibitors
  • Pharmaceutical Preparations
  • Cytochrome P-450 Enzyme System