Metoprolol × Verapamil

Both drugs slow conduction through the atrioventricular (AV) node and sinus node function, lower the heart rate and reduce cardiac contractility; together these effects add up (metoprolol and verapamil labels). There is also a pharmacokinetic part: in patients with angina, verapamil increased metoprolol AUC by 32.5% and peak concentration by 41% (verapamil label). The FDA verapamil label also describes reduced metoprolol clearance.

Marked bradycardia, high-degree atrioventricular (AV) block up to complete heart block, low blood pressure with dizziness, new or worsening heart failure (verapamil and metoprolol labels).

Do not give intravenous verapamil to patients taking beta-blockers, including metoprolol (metoprolol labels). Intravenous verapamil is contraindicated with intravenous beta-blockers; the two should not be given within a few hours of each other (intravenous verapamil labels in Spain and the US). Avoid oral verapamil with a beta-blocker in any degree of ventricular dysfunction; in hypertension the risks of the combination may outweigh the benefits (FDA verapamil label). If tablets are combined, use caution and monitor pulse and blood pressure closely (metoprolol and verapamil labels). If the pulse falls below 50–55 beats per minute, reduce metoprolol gradually or withdraw it slowly (metoprolol label). Marked first-degree atrioventricular (AV) block or progression to second- or third-degree block requires a lower verapamil dose, and rarely stopping it (FDA verapamil label).