Cytochrome P450 (CYP) enzyme (CYP)

Cytochrome P450 (CYP) enzymes are a superfamily of heme-containing proteins primarily located in the liver and intestines that facilitate the oxidative metabolism of a vast array of drugs and endogenous compounds. They are responsible for the phase I biotransformation of approximately 75% of clinically used medications, converting lipophilic substances into more water-soluble metabolites for easier excretion [StatPearls: NBK557669]. Beyond drug clearance, specific CYP isoforms play vital roles in the synthesis of steroid hormones, cholesterol, and vitamins, making them essential for physiological homeostasis [NCBI: PMC3042391]. The term "Multiple CYP isoforms" typically refers to the collective activity of several key enzymes, such as CYP3A4, CYP2D6, and CYP2C9, which are frequently involved in complex drug-drug interactions [PubMed: 21410313]. These interactions occur when a drug inhibits or induces one or more isoforms, leading to altered plasma concentrations of co-administered medications and potential toxicity. Furthermore, significant genetic polymorphisms within the CYP gene family result in diverse metabolic phenotypes, ranging from poor to ultra-rapid metabolizers, which necessitates personalized dosing strategies in clinical practice [NIH: Genetics Home Reference].

Other names

CYP450Cytochrome P450 monooxygenaseHemoprotein P450Microsomal monooxygenaseP450

Drugs interact with these enzymes as substrates for metabolic clearance, or as inhibitors and inducers that alter enzymatic activity. Therapeutic agents specifically target certain isoforms to inhibit the biosynthesis of endogenous signaling molecules, such as steroids in hormone-dependent cancers [StatPearls: NBK557669].