In a patient taking metoprolol succinate 25 mg twice daily who develops severe symptomatic bradycardia, should the beta‑blocker be stopped immediately or tapered?

Management of Severe Symptomatic Bradycardia on Metoprolol Succinate

In a patient taking metoprolol succinate 25 mg twice daily who develops severe symptomatic bradycardia, you should hold the medication immediately but avoid abrupt complete discontinuation—instead, reduce the dose by 50% once the patient stabilizes, then taper gradually over 1-2 weeks if discontinuation is necessary.

Immediate Management

Hold the Current Dose

• Stop metoprolol immediately when severe symptomatic bradycardia occurs (heart rate <50-60 bpm with symptoms such as dizziness, lightheadedness, syncope, or signs of hypoperfusion) 1.
• The European Society of Cardiology identifies symptomatic bradycardia as an absolute contraindication to continued beta-blocker therapy 2.
• Assess for hemodynamic instability including systolic blood pressure <100 mmHg with symptoms, altered mental status, chest discomfort, acute heart failure, or other signs of shock 1.

Rule Out Contributing Factors

• Check for drug interactions with other bradycardic agents including digoxin, calcium channel blockers (diltiazem, verapamil), amiodarone, or cytochrome P450 2D6 inhibitors like terbinafine 1, 3.
• Evaluate for other causes of bradycardia such as infection, hypothyroidism, increased intracranial pressure, or electrolyte abnormalities 1.

Acute Treatment if Needed

• If the patient remains severely symptomatic with bradycardia after holding metoprolol, administer atropine 0.5 mg IV every 3-5 minutes (maximum 3 mg total) as first-line therapy 1.
• Consider transcutaneous pacing if atropine is ineffective and the patient has persistent symptoms 2.

Critical Warning About Abrupt Discontinuation

Never abruptly stop metoprolol completely without a tapering plan, especially in patients with coronary artery disease or heart failure. The FDA label warns that abrupt discontinuation can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias 4. The ACC/AHA guidelines document that beta-blocker withdrawal is associated with a 2.7-fold increased risk of 1-year mortality compared to continuous use 1. One study reported a 50% mortality rate following abrupt metoprolol cessation 1.

Recommended Tapering Strategy

Once Patient Stabilizes

• Reduce the metoprolol dose by 50% (from 25 mg twice daily to 12.5 mg twice daily, or 12.5 mg once daily) rather than complete cessation 1.
• This maintains some beta-blockade benefit while reducing bradycardic risk, particularly important if the patient has underlying coronary disease or heart failure 1.
• The ACC/AHA perioperative guidelines specify holding beta-blockers when heart rate is consistently below 45 bpm, or delaying administration by 12 hours when heart rate is 45-49 bpm 1.

If Complete Discontinuation is Necessary

• The European Heart Journal recommends reducing the dose by approximately 25-50% every 1-2 weeks 1.
• Monitor for signs of worsening heart failure symptoms (increased fatigue, shortness of breath, edema, weight gain) during tapering 1.
• If symptoms worsen during tapering, temporarily return to the previous dose before attempting a more gradual taper 1.
• For patients with heart failure, more cautious tapering may be required with smaller incremental reductions 1.

Monitoring During and After Dose Adjustment

• Check heart rate, blood pressure, and symptoms within 1-2 weeks after reducing metoprolol 1.
• Watch specifically for worsening heart failure symptoms, new or worsening angina, or development of arrhythmias 1, 4.
• Heart rate should improve within days to 1-2 weeks with appropriate dose reduction 1.
• Maintain systolic blood pressure >100 mmHg during the adjustment period 1.

When to Resume Beta-Blockade

• Consider reintroducing beta-blockade only when heart rate consistently exceeds 55-60 bpm and systolic blood pressure exceeds 100 mmHg without symptoms 1.
• Restart metoprolol at the lowest possible dose (12.5 mg once daily) and titrate slowly over weeks 1.
• Some beta-blocker is better than no beta-blocker for patients with heart failure or coronary disease—the benefits are maintained even at lower doses 1.

Common Pitfalls to Avoid

• Do not assume the bradycardia is benign—always assess for symptoms and hemodynamic compromise before deciding on management 1.
• Do not completely stop metoprolol abruptly in patients with coronary artery disease or heart failure without a tapering plan 4.
• Do not restart at the previous dose that caused bradycardia—always use a lower dose or consider an alternative agent 1.
• Do not forget to check for drug interactions, particularly CYP2D6 inhibitors which can increase metoprolol levels by 50-80% 3, 5.

Alternative Considerations

• If beta-blockade is still needed for rate control but metoprolol is poorly tolerated, consider switching to a non-dihydropyridine calcium channel blocker (diltiazem 120-360 mg daily) after the patient stabilizes 1.
• For patients with heart failure requiring continued beta-blockade, specialist cardiology consultation is recommended if symptoms don't improve with dose adjustment 1.