Table 4 Rate-lowering agents
From: Clinical review: Clinical management of atrial fibrillation – rate control versus rhythm control
Drug | Dose | Contraindications | Comments |
|---|---|---|---|
β-Blockers (e.g. metoprolol) | 5 mg intravenous; can be repeated twice at 2-min intervals if necessary | Asthma, uncontrolled heart failure, bradycardia/heart block, Wolff–Parkinson–White | Useful in patients with concomitant coronary artery disease Use with caution in controlled heart failure |
Calcium channel blockers (e.g. diltiazem, verapmail) | Diltiazem: up to 300 mg/day orally Verapamil: 5–10 mg intravenous over 2 min; can be repeated once 30 min later | Bradycardia/heart block, left ventricular failure, Wolff–Parkinson–White, concomitant use of β-blockers not recommended | Diltiazem less negatively inotropic compared to verapamil Verapamil may cause elevation of digoxin levels |
Digoxin | 62.5–250 μg/day (initial loading dose required) | Bradycardia/heart block, Wolff–Parkinson–White | Renally excreted Slow onset of action Poor efficacy in hyperadrenergic states Hypokalaemia increases risk of toxicity |