What is the recommended initial dose of Amiodarone (Antiarrhythmic medication) for Advanced Cardiovascular Life Support (ACLS)?

Amiodarone Dosing for ACLS

For shock-refractory ventricular fibrillation or pulseless ventricular tachycardia during cardiac arrest, administer an initial dose of 300 mg IV/IO as a bolus, followed by a second dose of 150 mg IV/IO if VF/pVT persists. 1

Initial Dosing Algorithm

First dose: 300 mg IV/IO bolus 1

• Administer after CPR, defibrillation attempts, and vasopressor (epinephrine) have been given 1
• Give rapidly as a bolus during active resuscitation 1

Second dose: 150 mg IV/IO bolus 1

• Administer if VF/pVT recurs or persists after the first dose 1
• This is the maximum dosing recommended during cardiac arrest 1

Clinical Context and Timing

The 2018 American Heart Association guidelines represent an important shift from previous recommendations 1:

• Amiodarone and lidocaine are now considered equivalent options for shock-refractory VF/pVT, whereas older guidelines favored amiodarone as first-line 1
• This change reflects the reality that no antiarrhythmic drug has demonstrated improved long-term survival or favorable neurological outcomes in cardiac arrest 1
• The recommendation is based primarily on short-term benefits (ROSC, survival to hospital admission) rather than mortality reduction 1

Route of Administration

Intravenous or intraosseous routes are both acceptable 1:

• IV/IO access should be established early in the resuscitation 1
• Although there is limited experience with IO administration of amiodarone, it has been used anecdotally without known adverse effects 1

Integration into ACLS Algorithm

Amiodarone administration fits into the cardiac arrest sequence as follows 1:

• After the third shock for persistent VF/pVT, consider the first 300 mg dose 1
• Continue high-quality CPR with minimal interruptions (push hard at least 2 inches, rate 100-120/min, allow complete chest recoil) 1
• Administer epinephrine 1 mg IV/IO every 3-5 minutes throughout the resuscitation 1
• After the fifth shock for persistent VF/pVT, consider the second 150 mg dose 1

Important Caveats and Pitfalls

Hypotension risk: Amiodarone can cause bradycardia and hypotension, particularly when given IV 1:

• In one out-of-hospital study, a higher incidence of bradycardia and hypotension was reported with amiodarone 1
• Animal studies suggest administering a vasoconstrictor (epinephrine) before amiodarone may prevent hypotension 1
• The adverse hemodynamic effects are attributed to vasoactive solvents (polysorbate 80 and benzyl alcohol) in the IV formulation 1

Do not use for post-ROSC prophylaxis: There is no evidence supporting routine continuation of amiodarone after return of spontaneous circulation 1

Alternative if amiodarone unavailable: Lidocaine may be used with initial dose of 1-1.5 mg/kg IV, followed by 0.5-0.75 mg/kg at 5-10 minute intervals up to maximum 3 mg/kg 1

Evidence Quality Considerations

The dosing recommendations come from high-quality randomized controlled trials 1:

• Studies demonstrated that 300 mg amiodarone improved hospital admission rates compared to placebo in out-of-hospital VF/pulseless VT 1
• A dose of 5 mg/kg (approximately 300 mg for average adult) showed superiority over 1.5 mg/kg lidocaine for hospital admission 1
• However, these benefits did not translate to improved survival to hospital discharge or neurological outcomes 1