Selective β1-adrenoceptor blockers
ATC code: C07AB02 (Metoprolol)
Cardioselective β1-blocker without intrinsic sympathomimetic activity. Reduces heart rate, contractility and cardiac output and slows AV conduction. Lowers myocardial oxygen demand and has antiarrhythmic and antihypertensive effects. Metabolized by CYP2D6 – exposure is 2–5-fold higher in poor metabolizers.
First line
Beta-blockers are first-line in stable angina. Metoprolol reduces heart rate and myocardial oxygen consumption, decreasing angina attack frequency. After MI, beta-blockers reduce the risk of recurrent MI and sudden death. Target resting heart rate is 55-60 bpm.
First line
Metoprolol succinate is one of three beta-blockers proven to reduce mortality in HFrEF. The MERIT-HF trial demonstrated a 34% reduction in all-cause mortality. Start at 12.5-25 mg daily, titrate every 2 weeks to target dose of 200 mg. Succinate must not be substituted with tartrate – they are not equivalent in HF. 2021 includes metoprolol succinate among recommended beta-blockers for HF.
Only metoprolol succinate (extended-release form). Tartrate is not used in HF – no evidence base.
First line
Metoprolol is one of the first-choice agents for heart rate control and prevention of supraventricular tachycardia paroxysms. In acute SVT, metoprolol is given intravenously 5 mg over 2 minutes, repeatable up to 3 times at 5-minute intervals. Oral form is used for long-term prevention.
Individual decision
Beta-blockers as antihypertensive monotherapy in the absence of CAD, HF, tachyarrhythmia, or post-MI status are not first-line per 2024, 2017, and NG136. Metoprolol is prescribed in concurrent CAD, post-MI, or tachyarrhythmias. Less effective for stroke prevention than ACEi/ARB, CCB, or diuretics. Tartrate 50–100 mg twice daily or succinate 50–200 mg once daily. In younger patients without a compelling indication, other classes are preferred.
5 pairs found. Sorted from critical to minor.
Mechanism
Dual mechanism: 1) additive AV conduction slowing and heart rate reduction (amiodarone non-competitively blocks β-receptors, metoprolol selectively blocks β1); 2) amiodarone inhibits CYP2D6, doubling metoprolol concentration. Risk of symptomatic bradycardia, AV block, and hypotension.
Management
The combination is often justified in AF. Start metoprolol at a low dose (12.5–25 mg twice daily) and titrate by heart rate and BP. Monitor ECG (QT, AV conduction) every 3–6 months. In older adults, reduce the dose when resting heart rate drops below 55/min.
Sources
Mechanism
Additive AV conduction slowing and heart rate reduction. In AF, synergistic ventricular rate control is beneficial, but in older patients there is risk of symptomatic bradycardia, second- or third-degree AV block, and asystole.
Management
Start both drugs at low doses. Check ECG at 1–2 weeks and after each dose increase. Target resting heart rate is 60–70/min in HF and 80–110/min in AF (RACE II). For syncope or heart rate below 50/min, reduce the dose or discontinue.
Sources
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
Mechanism
A target combination in HFrEF and hypertension – synergistic BP and pre/afterload reduction. In older patients with hypovolemia or CKD, symptomatic hypotension and bradycardia can occur.
Management
Start both at low doses and titrate slowly. Check BP, heart rate, creatinine, and potassium at 1–2 weeks and with each dose increase.
Sources
Mechanism
A target combination in HF and hypertension. Synergistic BP reduction. In older patients, symptomatic hypotension and bradycardia can occur. The sartan does not mask hypoglycemia (unlike the β-blocker, which can).
Management
Start at low doses. Check BP, heart rate, creatinine, and potassium at 1–2 weeks. In diabetic patients, remember that metoprolol masks tachycardia during hypoglycemia.
Sources
FDA category C. Beta-blockers can cause fetal growth restriction, neonatal bradycardia, and hypoglycemia. If antihypertensive therapy is needed in pregnancy, labetalol or methyldopa are preferred.
Excreted in breast milk at concentrations exceeding plasma levels. Risk to the infant at standard doses is considered low, but monitor the neonate for signs of bradycardia.
metoprolol is evaluated for the following indications with varying evidence strength: Supraventricular tachycardia (evidence tier A), Coronary artery disease (evidence tier A), Heart failure (evidence tier A). See the full indication matrix with dosing and citations above on this page.
Common side effects of metoprolol (≥ 1 in 100): Bradycardia, Hypotension, Fatigue, weakness, Dizziness, Cold extremities. See the Safety section for uncommon and serious reactions.
FDA category C. FDA category C. Beta-blockers can cause fetal growth restriction, neonatal bradycardia, and hypoglycemia. If antihypertensive therapy is needed in pregnancy, labetalol or methyldopa are preferred.
Excreted in breast milk at concentrations exceeding plasma levels. Risk to the infant at standard doses is considered low, but monitor the neonate for signs of bradycardia.
metoprolol is contraindicated in: Second- or third-degree AV block without a pacemaker; Sick sinus syndrome without a pacemaker; Severe bradycardia (HR below 50 bpm before treatment); Severe bronchial asthma; Decompensated heart failure with pulmonary edema or cardiogenic shock. Full list in the Safety section.