Is metoprolol (beta-blocker) a suitable treatment option?

Should You Give Metoprolol?

Yes, metoprolol should be given, but only specific formulations (sustained-release metoprolol succinate, bisoprolol, or carvedilol) are recommended for heart failure with reduced ejection fraction (HFrEF), while metoprolol tartrate is appropriate for acute coronary syndromes, hypertension, and angina. The clinical context determines which formulation and indication is appropriate.

For Heart Failure with Reduced Ejection Fraction (LVEF ≤40%)

Use sustained-release metoprolol succinate (not metoprolol tartrate) as it is one of only three beta-blockers proven to reduce mortality in HFrEF. 1

• Metoprolol succinate, bisoprolol, and carvedilol are the only beta-blockers with Class 1 recommendation for reducing mortality and hospitalizations in HFrEF patients with current or previous symptoms 1
• Metoprolol tartrate (short-acting) was less effective in heart failure clinical trials and should not be used for this indication 1
• Initiate at 12.5-25 mg once daily and titrate to target dose of 200 mg once daily over weeks to months 1

Critical Contraindications in Heart Failure

Do not give metoprolol if the patient has: 1, 2

• Marked first-degree AV block (PR interval >0.24 seconds) or any second/third-degree AV block without pacemaker
• Severe left ventricular dysfunction with acute decompensated heart failure (rales, S3 gallop)
• Signs of low-output state (oliguria, sinus tachycardia reflecting low stroke volume)
• Symptomatic bradycardia (heart rate <50 bpm) or hypotension (systolic BP <90 mmHg)
• Killip Class II or III presentation (high risk for cardiogenic shock)

For Chronic Coronary Disease Without Heart Failure

In patients with chronic coronary disease and LVEF ≤40% with or without previous MI, beta-blocker therapy is recommended to reduce future major adverse cardiovascular events and cardiovascular death. 1

However, in patients with chronic coronary disease without previous MI or LVEF ≤50%, beta-blocker therapy provides no benefit in reducing major adverse cardiovascular events (Class 3: No Benefit recommendation). 1

• For post-MI patients with normal left ventricular function, it may be reasonable to reassess the indication for long-term (>1 year) beta-blocker therapy if there is no current LVEF ≤50%, angina, arrhythmias, or uncontrolled hypertension 1

For Acute Coronary Syndromes (Unstable Angina/NSTEMI)

Metoprolol should be started early in the absence of contraindications, particularly in patients with ongoing rest pain, tachycardia, or hypertension. 1

• Intravenous administration may be warranted for acute rate and blood pressure control 1
• Agents studied in the acute setting include metoprolol, propranolol, and atenolol 1
• If concerns exist about intolerance, favor short-acting beta-1-specific drugs like metoprolol or esmolol 1

Special Populations in ACS

For patients with chronic obstructive pulmonary disease or mild wheezing: 1

• Use a short-acting cardioselective agent at reduced dose (e.g., 12.5 mg metoprolol orally) rather than complete avoidance
• Mild wheezing or COPD history mandates caution but not absolute contraindication

For Hypertension and Stable Angina

Metoprolol is effective for hypertension and angina pectoris when used at oral dosages of 100-450 mg daily, typically administered twice daily. 2, 3

• Conventional formulations require twice daily dosing, though controlled-release formulations allow once-daily administration 2
• Metoprolol has been shown to be as effective as propranolol, methyldopa, and thiazide diuretics for hypertension 2

Critical Safety Considerations

Abrupt Discontinuation Warning

Never abruptly discontinue metoprolol in patients with coronary artery disease. 2

• Severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias have been reported following abrupt discontinuation 2
• When discontinuing chronically administered metoprolol, reduce dosage gradually over 1-2 weeks 2

Bronchospastic Disease

Patients with bronchospastic disease should generally not receive beta-blockers, but metoprolol's relative beta-1 selectivity allows cautious use in those who cannot tolerate other antihypertensive treatments. 2

• Use the lowest possible dose and consider three times daily dosing instead of twice daily to avoid higher plasma levels 2
• Bronchodilators, including beta-2 agonists, should be readily available 2

Diabetes and Hypoglycemia

Beta-blockers may mask tachycardia occurring with hypoglycemia, though other manifestations like dizziness and sweating remain detectable. 2

Formulation-Specific Guidance

The distinction between metoprolol formulations is critical: 1

Metoprolol Succinate (sustained-release):

• Proven mortality benefit in HFrEF
• Target dose: 200 mg once daily
• Preferred for heart failure

Metoprolol Tartrate (immediate-release):

• Appropriate for acute coronary syndromes, hypertension, angina
• Requires twice daily dosing
• NOT recommended for heart failure due to lack of mortality benefit