Moderate
amlodipine × metoprolol
Calcium channel blockers (dihydropyridines)×Selective β1-adrenoceptor blockers
Mechanism
A target combination in angina and hypertension. Amlodipine provides vasodilation and metoprolol slows heart rate – mutually offsetting reflex effects. In older patients with AV node dysfunction, excess bradycardia is possible. Unlike verapamil and diltiazem, amlodipine has minimal negative inotropy.
Management
Check heart rate and BP at 2 weeks after initiation. In patients over 75, obtain an ECG before initiation to assess AV conduction.
Sources
- Lexicomp: Lexicomp Drug Interactions (2024)— Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- Pharmaceutical Press: Stockley's Drug Interactions, 12th edition (2024)— Preston CL (ed.). Stockley's Drug Interactions. 12th ed. London: Pharmaceutical Press; 2024