Cytochrome P450 family 2 subfamily D (CYP2D)

The Cytochrome P450 family 2 subfamily D (CYP2D) is a group of heme-thiolate monooxygenases, with CYP2D6 being the sole functional member in humans [1.4.1, 1.4.2]. This enzyme family is a cornerstone of xenobiotic metabolism, responsible for the Phase I biotransformation of approximately 20-25% of all clinically prescribed medications, including antidepressants, antipsychotics, beta-blockers, and opioids [1.3.1, 1.3.2]. CYP2D6 is highly polymorphic, with over 100 known allelic variants that result in four distinct metabolizer phenotypes: poor, intermediate, normal, and ultrarapid [1.2.3, 1.3.4]. These genetic variations significantly influence drug plasma concentrations, leading to risks of toxicity or therapeutic failure, particularly for prodrugs like codeine and tamoxifen that require CYP2D6-mediated activation [1.2.5, 1.3.1]. Beyond its hepatic role, CYP2D6 is expressed in the brain and may contribute to the metabolism of endogenous neurosteroids and neurotransmitters like dopamine [1.2.5, 1.3.2]. Consequently, the CYP2D family is a primary focus of pharmacogenetic testing and a critical factor in managing drug-drug interactions [1.3.3, 1.5.1].

Other names

CYP2D6Debrisoquine 4-hydroxylaseSparteine oxygenaseP450-DB1P450C2DCytochrome P450 2D6

Oxidative metabolism of substrates including hydroxylation, demethylation, and dealkylation; bioactivation of prodrugs into active metabolites; inhibition of enzymatic activity by competitive or non-competitive binding [1.2.1, 1.2.5, 1.3.1].