When to Hold Metoprolol
Hold metoprolol when heart rate is consistently below 45 bpm, systolic blood pressure drops below 100 mmHg, or when signs of decompensated heart failure, cardiogenic shock, or high-grade AV block are present.
Critical Parameters for Holding Metoprolol
Bradycardia Thresholds
- Heart rate <50 bpm with worsening symptoms: Halve the dose or stop if severe deterioration occurs 1
- Heart rate consistently <45 bpm: Withhold metoprolol until recovery, then restart at reduced dose (100 mg daily) 2
- Heart rate 45-49 bpm with systolic BP >100 mmHg: Delay administration for 12 hours 2
Hypotension Parameters
- Systolic blood pressure <100 mmHg: Hold the dose until hemodynamic recovery 2, 3
- Symptomatic hypotension (dizziness, lightheadedness, confusion): Discontinue and reassess other vasodilators first 1
- Asymptomatic low blood pressure: Generally does not require stopping therapy 1
Cardiac Contraindications
Absolute contraindications requiring immediate discontinuation 4, 5:
- AV block greater than first degree (in absence of pacemaker)
- Sinoatrial node dysfunction (without pacemaker)
- Decompensated systolic heart failure
- Cardiogenic shock
- Signs of low cardiac output state
Respiratory Considerations
Context-Specific Holding Parameters
Post-Myocardial Infarction
In the acute MI setting, do not initiate metoprolol if the patient has 3:
- Signs of heart failure
- Evidence of low output state
- Increased risk for cardiogenic shock (age >70 years, systolic BP <120 mmHg, sinus tachycardia >110 bpm or HR <60 bpm)
- PR interval >0.24 seconds
- Second- or third-degree heart block
Perioperative Setting
The POISE trial demonstrated increased mortality and stroke risk with perioperative metoprolol, particularly when clinically significant hypotension developed—this had the largest population-attributable risk for death and stroke 2. Hold if hemodynamic instability occurs.
Important Clinical Caveats
Avoid Abrupt Discontinuation
Beta-blockers should not be stopped suddenly unless absolutely necessary—there is risk of rebound myocardial ischemia, infarction, and arrhythmias 1. Ideally seek specialist advice before discontinuation.
Dose Reduction vs. Complete Holding
For marked fatigue or mild bradycardia: Consider halving the dose rather than complete cessation, then review in 1-2 weeks 1. Complete discontinuation is rarely necessary.
Drug Interactions
Exercise caution when metoprolol is combined with other SA/AV nodal-blocking agents (digoxin, amiodarone, diltiazem, verapamil)—these increase risk of excessive bradycardia requiring dose holds 1, 4.
Overdose Management
Signs of metoprolol overdose include bradycardia, hypotension, bronchospasm, myocardial infarction, and cardiac failure 7. Manage symptomatically with vasopressors (norepinephrine, dopamine), beta-2 agonists for bronchospasm, and consider dobutamine or glucagon for cardiac failure.
Monitoring After Holding
When metoprolol is held and then restarted: