Why diltiazem cuse toxicity when taken with digoxin?

Answer 1

Diltiazem can cause toxicity when taken with digoxin because it inhibits the metabolism of digoxin, leading to increased levels of digoxin in the bloodstream. This interaction occurs due to diltiazem's effect on the cytochrome P450 enzymes, particularly CYP3A4, which are responsible for metabolizing digoxin. Elevated digoxin levels can result in toxicity, manifesting as nausea, vomiting, arrhythmias, or visual disturbances. Therefore, careful monitoring of digoxin levels is essential when these medications are co-administered.