Cytochrome P450 3A4/3A5 (CYP3A4/3A5)

Cytochrome P450 3A4 (CYP3A4) and Cytochrome P450 3A5 (CYP3A5) are the primary enzymes responsible for the hepatic and intestinal metabolism of the lincosamide antibiotic clindamycin [1, 4]. CYP3A4 is the dominant isoform, catalyzing the S-oxidation of clindamycin to its major metabolite, clindamycin sulfoxide, and N-demethylation to the minor metabolite, N-desmethylclindamycin [1, 12]. Both metabolites retain some biological activity, though the parent drug is the primary active form [3, 8]. Because clindamycin is a substrate for these enzymes, its pharmacokinetics are highly susceptible to drug-drug interactions with CYP3A4/5 inhibitors, such as ketoconazole and ritonavir, and inducers like rifampin [2, 13]. Such interactions can lead to either toxic accumulation or therapeutic failure, particularly in special populations with varying CYP3A activity [3, 11]. These enzymes are critical for the clearance of clindamycin, and their activity is influenced by genetic polymorphisms, age, and disease states like inflammation [14, 15]. Monitoring for potential interactions is essential when clindamycin is co-administered with potent modulators of the CYP3A system [4, 6].

Other names

CYP3A4CYP3A5Cytochrome P450 3A4Cytochrome P450 3A5Clindamycin S-oxidaseClindamycin N-demethylase

Metabolism of clindamycin via S-oxidation and N-demethylation; competitive and mechanism-based inhibition by inhibitors; transcriptional induction via PXR activation by inducers.