Diltiazem
Diltiazem is a nondihydropyridine calcium channel blocker that is used in the treatment of hypertension and angina. This cardiac drug undergoes hepatic metabolism by both CYP3A4 and CYP2D6 into two active metabolites, desacetyldiltiazem and desmethyldiltiazem.[5] In recent research, Zimmermann and colleagues identified a bacterium in the human gut that also contains enzymes that metabolize diltiazem into these two active metabolites.[5] The microorganism, Bacteroides thetaiotaomicron, may use these enzymes to deacetylate certain sugars as part of the normal digestive process, meaning that the effects on diltiazem are incidental.[10] How much the gut microbiome influences diltiazem's pharmacologic effects on blood pressure or heart rate remains unknown, but it is clear that serum concentrations of the parent drug and its less active metabolites are influenced by the metabolic capacity of B thetaiotaomicron in the gut when this organism is present.[10]
US Pharmacist. 2023;48(2):18-22. © 2023 Jobson Publishing
