Cytochrome P450 3A Enzyme Family (CYP3A)

The Cytochrome P450 3A (CYP3A) enzyme family is a subfamily of the cytochrome P450 superfamily, which are heme-thiolate monooxygenases involved in the metabolism of a wide range of endogenous and exogenous compounds. CYP3A enzymes play a critical role in drug metabolism, being responsible for the clearance of more than half of all currently prescribed medications. They also participate in the synthesis and breakdown of cholesterol, steroids, bile acids, and other lipids. The human CYP3A family consists primarily of four functional genes: CYP3A4, CYP3A5, CYP3A7, and CYP3A43. Among these, CYP3A4 is the most abundant isoform in adult liver and intestine and is considered the most important for drug metabolism. CYP3A5 is mainly expressed extra-hepatically but can be significant in some individuals due to genetic polymorphisms. CYP3A7 predominates in fetal liver. CYP3A43 remains less well characterized but has clinical significance due to genetic variation. Inhibitors or inducers can dramatically alter plasma concentrations of co-administered drugs metabolized by these enzymes—leading to toxicity or therapeutic failure.

Other names

CYP3A4CYP3A5CYP3A7CYP3A43

Oxidation of xenobiotics, leading to their deactivation or activation into pharmacologically active or toxic metabolites.