Moderate
Established
Description
Carvedilol increases digoxin plasma concentrations through P-gp inhibition and adds negative chronotropic and dromotropic effects, increasing the risk of bradycardia and AV block.
Mechanism
Carvedilol is a P-gp inhibitor and reduces renal tubular digoxin secretion; combined beta-blockade and digoxin effects on AV node conduction are additive.
Clinical Significance
Digoxin AUC may increase ~15–20%; symptomatic bradycardia and high-degree AV block have been reported.
Management
Monitor heart rate and digoxin levels; check ECG periodically; reduce digoxin dose when carvedilol is initiated.