Metoprolol IV Push Dosing for SVT
For supraventricular tachycardia (SVT), metoprolol should be administered intravenously at 5 mg over 1-2 minutes, which can be repeated at 5-minute intervals up to a maximum total dose of 15 mg. 1
Dosing Protocol
- Initial dose: 5 mg IV push over 1-2 minutes
- Wait 5-10 minutes to assess response
- If inadequate response and no adverse effects: Administer additional 5 mg IV push
- May repeat up to a total maximum dose of 15 mg (three 5 mg doses)
- Monitor vital signs continuously during administration
Clinical Considerations
Patient Monitoring
- Continuous ECG monitoring is mandatory during administration
- Monitor blood pressure before each dose
- Have resuscitation equipment immediately available
Contraindications
- Severe bradycardia
- Heart block greater than first degree
- Cardiogenic shock
- Decompensated heart failure
- Hypotension (systolic BP <100 mmHg)
Potential Adverse Effects
- Hypotension (most common side effect)
- Bradycardia
- Bronchospasm (particularly in patients with reactive airway disease)
- Worsening heart failure in patients with ventricular dysfunction
Alternative Agents for SVT
If metoprolol is contraindicated or ineffective, consider:
- Adenosine: 6 mg rapid IV bolus, followed by 12 mg if needed (first-line for most SVTs)
- Diltiazem: 0.25 mg/kg IV over 2 minutes, followed by infusion at 5-15 mg/hour
- Verapamil: 5-10 mg IV over 2 minutes
Important Cautions
- Never use in pre-excited atrial fibrillation or flutter (may accelerate ventricular response)
- Avoid combining with other AV nodal blocking agents with longer half-lives
- Use with extreme caution in patients with asthma or COPD
- Hypotension may occur but is usually transient and manageable 2
Efficacy
Metoprolol has been shown to effectively reduce ventricular rate in 69-81% of patients with SVT, with rate reductions of 26-60 beats/minute in responders 2. The drug works by slowing conduction through the AV node and increasing AV nodal refractoriness 3.
For ongoing management after acute conversion, oral metoprolol may be considered at doses of 50-100 mg twice daily for prophylaxis against recurrent episodes 3, 4.