Cytochrome P450 (CYP450) enzymes are a class of enzymes widely involved in drug metabolism, particularly in the liver where they catalyze the oxidation of numerous drugs. Induction of CYP450 enzymes occurs primarily through nuclear receptors, such as the pregnane X receptor (PXR), the constitutive androstane receptor (CAR), and the aryl hydrocarbon receptor (AhR). By binding to ligands, such receptors can heterodimerize and diffuse to the nucleus, which in turn targets the regulatory sites of CYP enzyme genes and enhances the enzymes' gene expression. CYP450 induction is an important consideration in drug development and clinical application because it can significantly affect the pharmacokinetics and efficacy of drugs.
A drug that induces CYP can reduce the concentration of other drugs sharing the same metabolism pathway and thus reduce their efficacy or promote metabolite toxicity. Thus, to accurately forecast the likelihood of drug-drug interactions, it is essential that a correct assessment of the risk of CYP induction be made in the initial stages of drug development. Such predictions can avoid undesirable drug interactions and enhance drug safety and effectiveness.