Cytochrome P450 family (CYP) (CYP)

Cytochrome P450 (CYP) enzymes are a superfamily of heme-containing monooxygenases primarily located in the liver and intestines, where they catalyze the Phase I metabolism of approximately 75% of clinically used drugs (Source: NIH [1.3.4]). CYP2D6 is a particularly critical isoform, responsible for the metabolism of about 20-25% of medications, including antidepressants, antipsychotics, beta-blockers, and opioids (Source: NIH [1.1.2, 1.3.5]). These enzymes play a dual role: they detoxify xenobiotics and activate prodrugs, such as the conversion of codeine to morphine (Source: NHS [1.1.1]). Genetic polymorphisms in CYP genes, especially CYP2D6, lead to significant inter-individual variability in drug response, resulting in phenotypes ranging from poor to ultra-rapid metabolizers (Source: NIH [1.1.5, 1.3.3]). While often viewed as metabolic "off-targets" responsible for drug-drug interactions, certain isoforms like CYP19A1 (aromatase) and CYP17A1 are direct therapeutic targets for treating cancer and endocrine disorders (Source: NIH [1.2.2, 1.2.5]). Understanding the activity and genetic profile of these enzymes is essential for personalized medicine and avoiding adverse drug reactions (Source: NIH [1.3.2]). Drug-drug interactions involving CYP inhibition or induction can lead to therapeutic failure or severe toxicity (Source: NIH [1.3.5]). Consequently, CYP enzymes are a major focus in drug development and clinical pharmacology (Source: NIH [1.3.4]).

Other names

CYP450Cytochrome P450 monooxygenaseHeme-thiolate proteinMicrosomal monooxygenase

Substrate oxidation (Phase I metabolism), enzyme inhibition (competitive or mechanism-based), and enzyme induction (transcriptional upregulation).