Should Metoprolol XL (Metoprolol succinate) be continued on the day of surgery?

Metoprolol XL Should Be Continued on the Day of Surgery for Patients Already Taking It

If a patient is already on Metoprolol XL (metoprolol succinate) for a Class I indication (such as heart failure, coronary artery disease, hypertension, or arrhythmias), the medication must be continued through the perioperative period, including the day of surgery. 1

Key Recommendations by Patient Status

For Patients Already on Beta-Blockers (Class I - Must Continue)

• Continue metoprolol XL without interruption in patients who are chronically taking beta-blockers for established indications 1
• Abrupt discontinuation is classified as Class III: Harm - meaning it is potentially harmful and should not be done 1
• The dose should be titrated perioperatively based on heart rate and blood pressure, targeting a heart rate of 60-80 bpm while avoiding hypotension 1
• Continue the medication through hospital discharge unless clear contraindications arise 1

For Beta-Blocker Naïve Patients (Class III: Harm - Do Not Start)

• Do not initiate metoprolol on the day of surgery - this is associated with increased mortality, stroke risk, and hypotension 1, 2
• The POISE trial demonstrated that starting high-dose extended-release metoprolol on the day of surgery in beta-blocker naïve patients resulted in more deaths (3.1% vs 2.3%) and more strokes (1.0% vs 0.5%) despite reducing myocardial infarction 2
• If beta-blockers are indicated for a new diagnosis, they should be initiated at least 7 days before surgery with dose titration, not on the day of surgery 1

Critical Clinical Pitfalls to Avoid

The Withdrawal Syndrome

• Sudden discontinuation of chronic beta-blockers can precipitate rebound hypertension, tachycardia, and acute coronary syndromes 1
• This withdrawal effect may have actually contributed to the apparent "benefit" seen in early beta-blocker studies - the harm was from stopping them in control groups, not benefit from continuing them 1

Perioperative Hemodynamic Management

• Monitor closely for bradycardia (heart rate <50 bpm) and hypotension which are more common with metoprolol 2
• In the POISE trial, patients receiving metoprolol had significantly more intraoperative bradycardia requiring treatment (53/246 vs 19/250) and hypotension requiring treatment (114/246 vs 84/250) 3
• Use clinical judgment to temporarily hold or reduce doses if significant bradycardia or hypotension develops, but plan to resume as soon as hemodynamically stable 1

Specific Dosing Considerations

On the Day of Surgery

• Give the usual morning dose for patients on chronic therapy 1
• May need to use intravenous formulations if patient is NPO, though metoprolol XL can typically be given with a sip of water 4
• Target heart rate control of 60-80 bpm without inducing hypotension (systolic BP <100 mmHg) 1

Drug Interactions to Consider

• General anesthetics may enhance the cardiodepressant effects of beta-blockers 4
• Calcium channel blockers given concurrently can produce additive negative chronotropic and inotropic effects 4
• CYP2D6 inhibitors (fluoxetine, paroxetine, quinidine) can increase metoprolol levels and reduce cardioselectivity 4

Evidence Quality and Reconciliation

The evidence strongly supports continuation but not initiation of perioperative beta-blockers. The 2009 ACC/AHA guidelines explicitly state: "the POISE results do not address continuation of beta blockers in patients undergoing surgery" 1. The harm demonstrated in POISE was specifically in beta-blocker naïve patients started on high-dose metoprolol without titration 2.

The most recent 2024 ACC/AHA guideline reaffirms this distinction, maintaining Class I recommendation for continuation in patients with established indications while strengthening the Class III: Harm recommendation against day-of-surgery initiation 1.

The bottom line: Continue metoprolol XL in patients already taking it, but never start it on the day of surgery in beta-blocker naïve patients.