MajorCardiac glycosides (digitalis)×Selective β1-adrenoceptor blockers
Updated · Methodology
Mechanism
Additive slowing of atrioventricular (AV) conduction and lowered heart rate. In atrial fibrillation this synergistic ventricular rate control is standard; without atrial fibrillation, bradycardia and AV block risks rise.
Symptoms
Bradycardia (heart rate below 50/min), dizziness, syncope. ECG: first- to second-degree AV block, prolonged PR. Older patients: fatigue, weakness.
Management
The combination is appropriate in atrial fibrillation with preserved or reduced ejection fraction. Check pulse and ECG at 1 and 4 weeks. If pulse drops below 50 or second-degree AV block appears, reduce metoprolol; if symptoms persist, hold digoxin temporarily.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
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Medicine list: everything you take in one place →
Sources
- ESC: ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (2021)– McDonagh TA et al. Eur Heart J 2021;42:3599-3726
- ESC: 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the EACTS (2024)– Eur Heart J 2024;45(36):3314–3414
- RACE II Investigators: Lenient versus Strict Rate Control in Patients with Atrial Fibrillation (2010)– N Engl J Med 2010;362(15):1363–1373