Moderate
Probable
Description
Carvedilol combined with diltiazem increases the risk of bradycardia, hypotension, and AV block through additive cardiac depressant effects and pharmacokinetic interaction.
Mécanisme
Diltiazem inhibits CYP2D6 (a pathway for carvedilol metabolism), increasing carvedilol exposure; diltiazem also inhibits AV nodal conduction via calcium channel blockade, adding to carvedilol's beta-blocking effects.
Signification clinique
Symptomatic bradycardia and hypotension requiring treatment have been reported; risk is highest in patients with systolic heart failure.
Prise en charge
Start carvedilol at minimal dose; monitor heart rate and blood pressure closely when combining; perform ECG if symptomatic bradycardia suspected.