How should I manage a patient who is currently taking both atenolol and metoprolol?

Discontinue One Beta-Blocker Immediately

A patient should never be on both atenolol and metoprolol simultaneously—this represents inappropriate polypharmacy with redundant beta-blockade that significantly increases risks of bradycardia, heart block, hypotension, and other adverse effects without additional therapeutic benefit. 1

Immediate Action Required

Stop one of these medications immediately. Both atenolol and metoprolol are cardioselective beta-1 blockers with overlapping mechanisms of action 2, 3. Using them together provides no additive benefit but compounds the risk of:

• Severe bradycardia (heart rate <50 bpm with symptoms) 1
• Heart block requiring pacemaker 1
• Symptomatic hypotension with dizziness and syncope 1
• Acute decompensated heart failure in susceptible patients 1
• Cardiogenic shock 4

Which Beta-Blocker to Continue

If the patient has heart failure with reduced ejection fraction (HFrEF), discontinue atenolol and continue metoprolol succinate (extended-release formulation), as metoprolol succinate (along with bisoprolol and carvedilol) has proven mortality benefit in HFrEF 1, 2, 3. Atenolol is not evidence-based for HFrEF.

For hypertension alone without heart failure or ischemic heart disease, consider discontinuing metoprolol and continuing atenolol, as recent large-scale real-world evidence suggests atenolol may be associated with lower all-cause mortality (7.0% vs 13.1%) and cardiovascular mortality (1.4% vs 3.7%) compared to metoprolol tartrate 5. Additionally, atenolol demonstrates better adherence rates and blood pressure control in population studies 5, and is associated with fewer CNS side effects (sleep disturbance, vivid dreams, sexual dysfunction) due to its lower lipophilicity 6.

For acute myocardial infarction, metoprolol is preferred over atenolol based on experimental evidence showing metoprolol's unique anti-inflammatory effects that reduce infarct size—an effect not observed with atenolol or propranolol 7.

Discontinuation Protocol

Do not stop beta-blockers abruptly unless absolutely necessary, as this risks rebound hypertension, myocardial ischemia, infarction, and arrhythmias 1, 8.

Safe Discontinuation Steps:

1. Identify which beta-blocker to discontinue based on the patient's primary indication (see above)
2. Taper the discontinued agent over 1-2 weeks while maintaining the other at current dose
3. Monitor closely for:
   • Heart rate and blood pressure at each visit
   • Symptoms of ischemia (chest pain, dyspnea)
   • Signs of heart failure exacerbation (weight gain, edema, orthopnea)
4. Check ECG to exclude heart block before and after discontinuation 1

Monitoring After Consolidation

Once on a single beta-blocker:

• Target heart rate: 60-70 bpm at rest for most indications 1
• Acceptable blood pressure: Asymptomatic low blood pressure does not require intervention 1
• Symptomatic bradycardia (<50 bpm with symptoms): Reduce dose or discontinue 1
• Check renal function and electrolytes at 1-2 weeks after dose changes 1

Common Pitfall

The most critical error is continuing both medications or stopping both abruptly. This situation likely represents a prescribing error (duplicate therapy from different providers) or medication reconciliation failure. Review the patient's complete medication list and clarify the intended regimen with all prescribers involved.