Almost every patient treated with quinidine will have a decrease in the renal clearance of digoxin and many will have a decrease in the volume of distribution of digoxin. Whether changes in the inotropic effect of digoxin occur during concurrent quinidine administration is an unsettled area.

Which mechanism is responsible for interaction between quinidine and digoxin?

Considering the reduction of renal digoxin clearance, the mechanism mainly responsible for the quinidine-digoxin interaction, the decrease in renal quinidine clearance, appears to be most remarkable as well.

What drugs should digoxin patients avoid?

Other medications can affect the removal of digoxin from your body, which may affect how digoxin works. Examples include azole antifungals (such as itraconazole), dronedarone, lapatinib, macrolide antibiotics (such as clarithromycin, erythromycin), propafenone, rifampin, St. John's wort, among others.