Propranolol Dosing for SVT Control
For acute SVT control in adults, intravenous propranolol should be administered at 1 mg IV over 1 minute, repeated every 2 minutes as needed up to a total dose of 0.1 mg/kg (typically 5-7 mg maximum), while for ongoing oral management, propranolol 240 mg/day in divided doses is effective. 1
Acute Intravenous Administration
For hemodynamically stable SVT when adenosine is ineffective or contraindicated:
- Administer propranolol 1 mg IV slowly over 1 minute 1
- Repeat every 2 minutes as needed based on heart rate and blood pressure response 1
- Maximum total dose: 0.1 mg/kg (approximately 5-7 mg for average adult) 1
- This is particularly reasonable in pregnant patients with SVT when adenosine fails 1
Critical Monitoring During IV Administration
- Continuous ECG monitoring is essential throughout administration 2
- Check blood pressure and heart rate before each dose 2
- Watch for symptomatic bradycardia (HR <60 bpm with dizziness) 2
- Monitor for hypotension (systolic BP <100 mmHg with symptoms) 2
- Assess for bronchospasm, especially in patients with any reactive airway history 2
Absolute Contraindications for IV Propranolol
- Active asthma or reactive airways disease 2
- Heart failure signs or low output state 2
- Second- or third-degree heart block without pacemaker 2
- Systolic BP <100 mmHg with symptoms 2
- Pre-excited atrial fibrillation/flutter (WPW syndrome) 2
Ongoing Oral Management
For chronic SVT prevention in patients not undergoing catheter ablation:
- Standard dose: Propranolol 240 mg/day in divided doses (typically 80 mg three times daily or 120 mg twice daily) 1
- Start with lower doses (40-80 mg twice daily) and titrate upward based on response 1
- This dose was studied and found equally effective as verapamil 480 mg/day and digoxin 0.375 mg/day 1
Alternative Oral Approaches
"Pill-in-the-pocket" strategy for infrequent episodes:
- Combination of diltiazem plus propranolol can be used for self-administration to terminate AVNRT 1
- Important caveat: Episodes of syncope have been observed with this approach, so safety remains unclear 1
- Patients should seek medical attention if oral therapy fails to terminate the arrhythmia 1
Special Populations
Pregnant patients:
- Propranolol is reasonable for ongoing management of highly symptomatic SVT 1
- Can be used alone or in combination with other agents (digoxin, flecainide, metoprolol, propafenone, sotalol, verapamil) 1
- IV propranolol is reasonable for acute treatment when adenosine is ineffective 1
Pediatric patients:
- Oral dosing ranges from 0.5 to 4.0 mg/kg/day with few side effects 3
- High-dose therapy (7-14 mg/kg/day, average 9 mg/kg/day) has been used successfully for refractory cases 4
- No adverse reactions were encountered at these higher doses in children 4
Continuous Infusion for Refractory Cases
For hospitalized patients with refractory SVT when oral therapy is contraindicated:
- Loading dose: approximately 52 micrograms/kg IV 5
- Initial maintenance infusion: 16 micrograms/kg/hr (range 6-56 micrograms/kg/hr) 5
- Subsequent doses adjusted based on clinical response (range 3.9-74.9 micrograms/kg/hr) 5
- This approach decreased heart rate from 146 to 98 beats/min and was well-tolerated 5
- Average infusion duration was 97 hours 5
Clinical Context and Positioning
Propranolol is positioned as a first-line agent for ongoing SVT management alongside other beta blockers, diltiazem, and verapamil in patients without ventricular pre-excitation 1. However, catheter ablation should be strongly considered as it provides definitive treatment, and most patients now undergo ablation at younger ages rather than committing to long-term pharmacological therapy 1.
For patients who are not candidates for or prefer not to undergo catheter ablation, propranolol remains an effective option, though it is generally reserved after consideration of other beta blockers like metoprolol, which may have more favorable dosing profiles 1, 2.