What is the recommended Amiodarone (antiarrhythmic agent) bolus dose for a patient with arrhythmia?

Amiodarone Bolus Dose Recommendations

For life-threatening ventricular arrhythmias or stable wide-complex tachycardias, administer 150 mg IV over 10 minutes, which may be repeated if necessary. 1, 2, 3

Cardiac Arrest Protocol (VF/Pulseless VT)

For cardiac arrest with ventricular fibrillation or pulseless ventricular tachycardia unresponsive to defibrillation and epinephrine, give 300 mg IV/IO bolus over 10 minutes, followed by a second dose of 150 mg if the rhythm persists. 2

Standard Acute Treatment Protocol

Initial Loading Dose

• Administer 150 mg IV diluted in 100 mL D5W over 10 minutes for hemodynamically stable patients with life-threatening ventricular arrhythmias or atrial fibrillation with rapid ventricular response 1, 2, 3
• This bolus may be repeated in 10-30 minutes if arrhythmia persists or recurs 1
• Do not exceed an initial infusion rate of 30 mg/min 3

Maintenance Infusion Following Bolus

• After the initial bolus, continue with 1 mg/min for 6 hours (360 mg total), then 0.5 mg/min for the remaining 18 hours (540 mg total) 1, 2, 3
• Total dose over the first 24 hours should not exceed 2.2 g 1, 3
• Mean daily doses above 2100 mg are associated with increased risk of hypotension 3

Breakthrough Arrhythmia Management

• For breakthrough episodes of VF or hemodynamically unstable VT during maintenance infusion, give supplemental 150 mg boluses (mixed in 100 mL D5W) infused over 10 minutes 3

Administration Requirements

Vascular Access Considerations

• Use a central venous catheter for amiodarone concentrations >2 mg/mL 2, 3
• For infusions >1 hour, do not exceed 2 mg/mL concentration unless using a central line to prevent severe peripheral vein phlebitis 2, 3
• Administer through a volumetric infusion pump (not drop counters, which can underdose by up to 30%) 3
• Use an in-line filter during administration 3

Solution Preparation

• Dilute in D5W only; use glass or polyolefin bottles for infusions exceeding 2 hours 3
• Do not use evacuated glass containers for admixing due to incompatibility risk 3

Critical Monitoring During Bolus Administration

Cardiovascular Monitoring

• Monitor continuously for hypotension (occurs in 16% of IV patients) 2, 3
• Watch for bradycardia (occurs in 4.9% of IV patients) and AV block 1, 2
• Assess QT interval for excessive prolongation 2
• Monitor blood pressure closely, particularly during the 10-minute bolus infusion 1

Immediate Availability Requirements

• Have a defibrillator immediately available during administration 2
• Ensure resuscitation equipment is at bedside 2

Absolute Contraindications to Bolus Administration

• Second- or third-degree AV block without a functioning pacemaker 2
• Sick sinus syndrome or severe sinus node dysfunction without pacemaker 2
• Acute inflammatory lung disease 2

High-Risk Populations Requiring Extreme Caution

• Hepatic dysfunction (use with extreme caution) 2
• Heart transplant recipients (contraindicated) 2
• Patients on QT-prolonging drugs (avoid concomitant use without expert consultation) 2

Critical Drug Interactions During Acute Administration

• Reduce digoxin dose by 50% immediately, as amiodarone doubles digoxin levels 2
• Reduce warfarin dose by 33-50% and monitor INR at least weekly (interaction peaks at 7 weeks) 2
• Avoid combining with other QT-prolonging agents 2

Alternative Dosing for Specific Scenarios

Atrial Fibrillation with Rapid Ventricular Response

• A higher initial bolus of 450 mg over 30 minutes has been studied, with an additional 300 mg if ventricular rate exceeds 100 bpm after 30 minutes, though this is not standard guideline-recommended dosing 4
• Standard 150 mg bolus followed by infusion remains the guideline-recommended approach for atrial fibrillation 1

Pediatric Dosing

• 5 mg/kg rapid bolus (maximum 300 mg) IV/IO, with possible repeat up to total daily dose of 15 mg/kg 2
• Defibrillator must be immediately available 2

Common Pitfalls to Avoid

• Never use drop counter infusion sets - they can underdose by up to 30% due to altered surface properties of amiodarone solutions 3
• Never infuse concentrations >2 mg/mL through peripheral veins for >1 hour - this causes severe phlebitis 2, 3
• Never administer rapid boluses faster than 10 minutes - this significantly increases hypotension risk 1, 3
• Do not assume immediate antiarrhythmic effect - while IV onset is rapid (<30 minutes), full effect may take longer 1