Amiodarone Dosing for SVT
For supraventricular tachycardia (SVT), administer amiodarone as a 150 mg IV bolus over 10 minutes, followed by a continuous infusion of 1 mg/min for 6 hours, then 0.5 mg/min for the remaining 18 hours. 1
Intravenous Administration Protocol
Initial Loading Dose
- Give 150 mg IV over 10 minutes as the initial bolus 1
- This can be repeated if the arrhythmia persists or recurs 1
- Supplemental boluses of 150 mg may be administered over 10-30 minutes for breakthrough arrhythmias, but limit to 6-8 supplemental boluses in any 24-hour period 1
Maintenance Infusion
- After the initial bolus, start 1 mg/min infusion for 6 hours (total 360 mg) 1
- Then reduce to 0.5 mg/min for the remaining 18 hours (total 540 mg) 1
- The total dose over 24 hours should not exceed approximately 2.2 grams 2
Important Clinical Considerations
Monitoring Requirements
- Continuous ECG monitoring is mandatory during administration 1
- A defibrillator must be immediately available 1
- Watch closely for hypotension, which is the most common adverse effect (occurs in 26% of patients) 3
- Monitor for bradycardia, QT prolongation, and heart block 1
Managing Hypotension
- If hypotension develops, slow the infusion rate 1
- Consider adding vasopressor drugs, positive inotropic agents, or volume expansion as needed 1
Contraindications to Avoid
- Do not use in patients with second- or third-degree AV block unless a functioning pacemaker is present 4
- Contraindicated in cardiogenic shock and marked sinus bradycardia 4
- Avoid in patients with known hypersensitivity to amiodarone or iodine 4
Transitioning to Oral Therapy
If long-term therapy is needed after IV administration:
- For IV therapy <1 week: start 800-1,600 mg oral daily 2
- For IV therapy 1-3 weeks: start 600-800 mg oral daily 2
- For IV therapy >3 weeks: start 400 mg oral daily 2
- Continue loading until 10 grams total cumulative dose is reached, then reduce to maintenance dose of 200-400 mg daily 2
Critical Pitfalls to Avoid
Drug Interactions
- Reduce warfarin dose by 50% if co-administered, as amiodarone significantly increases INR 1
- Reduce digoxin dose by 30-50% due to P-glycoprotein inhibition 1
- Amiodarone inhibits multiple CYP enzymes (2C9, 2D6, 3A4) and increases exposure to many other drugs 1, 4
Dilution and Administration
- Concentration should not exceed 2 mg/mL and must be diluted with D5W 1
- Use central venous access when possible to minimize phlebitis risk 1