What is the recommended dosing regimen for Amiodarone (Amiodarone) for the treatment of ventricular (V) tachycardia?

From the Guidelines

For ventricular tachycardia, amiodarone is typically administered with a loading dose of 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours or until the arrhythmia is controlled. This dosing regimen is based on the most recent and highest quality study available, which prioritizes morbidity, mortality, and quality of life as the outcome 1. The medication works by blocking potassium channels, prolonging repolarization, and extending the refractory period, which helps suppress abnormal electrical activity in the ventricles.

Key Considerations

• The recommended starting dose is 500 mg per 24 hours, given in three stages: (1) rapid infusion of 150 mg over 10 minutes, (2) an early maintenance infusion of 1 mg/min for 6 hours, and (3) later maintenance infusion of 0.50 mg/min 1.
• For long-term maintenance therapy, oral amiodarone is given at 400-600 mg daily in divided doses for 2-4 weeks, then reduced to 200-400 mg daily.
• In emergency situations such as cardiac arrest with refractory ventricular fibrillation or pulseless ventricular tachycardia, a 300 mg IV bolus can be given, with a possible second dose of 150 mg if needed.
• Regular follow-up with ECGs, liver function tests, thyroid function tests, and pulmonary function assessments is essential during long-term therapy to monitor for adverse effects including thyroid dysfunction, pulmonary toxicity, liver abnormalities, and QT interval prolongation.

Dosing Regimen

• Loading dose: 150 mg IV over 10 minutes
• Early maintenance infusion: 1 mg/min for 6 hours
• Later maintenance infusion: 0.5 mg/min for 18 hours or until the arrhythmia is controlled
• Long-term maintenance therapy: oral amiodarone 400-600 mg daily in divided doses for 2-4 weeks, then reduced to 200-400 mg daily 1.

The dosing regimen should be titrated according to patient response, and careful monitoring for adverse effects is essential due to the medication's long half-life and potential for tissue accumulation 1.

From the FDA Drug Label

AMIODARONE HYDROCHLORIDE injection, for intravenous use ... DOSAGE AND ADMINISTRATION • The recommended starting dose is about 1000 mg over the first 24 hours of therapy, delivered by the following infusion regimen ( 2): • Initial Load: 150 mg in 100 mL (in D 5W) infused over 10 minutes • Followed by: 1 mg/min for 6 hours • Followed by: 0. 5 mg/min thereafter • For breakthrough episodes of VF or hemodynamically unstable VT, repeat the Initial Load ( 2)

The recommended dosing regimen for Amiodarone for the treatment of ventricular (V) tachycardia is:

• Initial Load: 150 mg in 100 mL (in D 5W) infused over 10 minutes
• Followed by: 1 mg/min for 6 hours
• Then: 0.5 mg/min thereafter
• For breakthrough episodes of VF or hemodynamically unstable VT, repeat the Initial Load 2

From the Research

Amiodarone Dosing for V Tach

• The recommended dosing regimen for Amiodarone for the treatment of ventricular tachycardia varies depending on the study and the specific patient population.
• A study from 1988 3 found that intravenous amiodarone was effective in suppressing sustained ventricular tachycardia in 7 out of 13 patients, but recommended modifying the dosing protocol to a lower initial bolus and a higher early maintenance infusion rate due to significant hemodynamic deterioration.
• Another study from 1983 4 used a loading dose of 800 mg/day for 6 weeks and a maintenance dose of 600 mg/day, and found that 69% of patients had no recurrence of symptomatic ventricular tachycardia or ventricular fibrillation over a follow-up of 6 to 52 months.
• A study from 1990 5 used a high-dose intravenous amiodarone regimen of 5 mg/kg over 30 minutes followed by 20 to 30 mg/kg/day as a constant infusion for 5 days, and found that 63% of patients responded to the treatment.
• A prospective, randomized study from 1993 6 compared conventional and high-dose loading regimens of amiodarone, and found that the therapeutic and electrophysiologic effects of the two regimens did not differ significantly after 3 or 10 days of therapy.
• A multicenter trial from 1996 7 found that intravenous amiodarone was effective in 40.3% of patients with recurrent hypotensive ventricular tachyarrhythmias refractory to standard therapies, and that there was no clear dose-response relation observed in the trial.

Dosing Regimens

• Intravenous amiodarone: 5 mg/kg over 30 minutes followed by 20 to 30 mg/kg/day as a constant infusion for 5 days 5
• Oral amiodarone: 800 mg/day for 6 weeks, followed by 600 mg/day for maintenance 4
• High-dose oral amiodarone: 50 mg/kg body weight per day on days 1 to 3,30 mg/kg per day on days 4 and 5, and 600 mg twice a day on days 6 to 10 6
• Intravenous amiodarone: 525,1,050, or 2,100 mg/24 h by continuous infusion over 24 h 7