What is the protocol for an Amiodarone (antiarrhythmic medication) drip?

Amiodarone Drip Protocol

For life-threatening ventricular arrhythmias, administer an initial loading dose of 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours (360 mg), then 0.5 mg/min for the remaining 18 hours (540 mg), with a maximum total dose of 2.2 g over 24 hours. 1, 2, 3

Initial Loading Protocol

First 24 Hours

• Loading bolus: 150 mg IV over 10 minutes 1, 2, 3
• Early maintenance: 1 mg/min for 6 hours (total 360 mg) 1, 3
• Late maintenance: 0.5 mg/min for 18 hours (total 540 mg) 1, 3
• Total first 24 hours: Approximately 1000 mg (do not exceed 2.2 g/24 hours) 1, 3

Cardiac Arrest Dosing (VF/Pulseless VT)

• Initial bolus: 300 mg IV/IO over 10 minutes if unresponsive to defibrillation and epinephrine 2
• Second bolus: 150 mg IV/IO if rhythm persists 2

Breakthrough Arrhythmias

• Supplemental dose: 150 mg in 100 mL D5W over 10 minutes for breakthrough VF or hemodynamically unstable VT 3
• Monitor closely for hypotension with supplemental dosing 3

Administration Requirements

Vascular Access and Concentration

• Central line mandatory for concentrations >2 mg/mL 2, 3
• For infusions >1 hour, do not exceed 2 mg/mL concentration unless using central line 2, 3
• Concentrations >3 mg/mL cause high incidence of peripheral vein phlebitis 3
• Use volumetric infusion pump (drop counters can underdose by up to 30%) 3

Solution Preparation

• Mix in D5W only 3
• Use glass or polyolefin bottles for infusions >2 hours 3
• Do not use evacuated glass containers (causes precipitation) 3
• Use in-line filter during administration 3
• Administer through dedicated central line when possible 3

Ongoing Maintenance After 24 Hours

• Continue 0.5 mg/min (720 mg/24 hours) 1, 3
• May increase rate to achieve arrhythmia suppression 3
• Can continue for 2-3 weeks regardless of age, renal function, or left ventricular function 3
• Limited experience beyond 3 weeks of IV therapy 3

Critical Monitoring Parameters

Cardiovascular Monitoring

• Continuous cardiac monitoring throughout IV administration 1
• Blood pressure: Hypotension occurs in 16% of IV patients 2, 3
• Heart rate: Bradycardia occurs in 4.9% of IV patients 2
• ECG: Monitor for AV block, heart block, and QT prolongation 1, 2

Dose-Related Adverse Effects

• Mean daily doses >2100 mg associated with increased hypotension risk 3
• Do not exceed initial infusion rate of 30 mg/min 3
• Faster infusions at higher concentrations than recommended have caused hepatocellular necrosis, acute renal failure, and death 3

Transition to Oral Therapy

Timing Based on IV Duration

• <1 week IV: Start 800-1600 mg oral daily 4
• 1-3 weeks IV: Start 600-800 mg oral daily 4
• Begin oral dosing while IV infusion continues at 0.5 mg/min 4

Oral Loading Strategy

• Continue loading until total of 10 g administered orally 1, 4
• Then reduce to maintenance dose of 200-400 mg daily for ventricular arrhythmias 1, 4
• For atrial fibrillation maintenance: 200 mg daily 1, 4

Drug Interactions Requiring Immediate Dose Adjustment

Critical Interactions During Transition

• Warfarin: Reduce dose by 30-50%, check INR within 3-5 days 4
• Digoxin: Reduce dose by 50% immediately (amiodarone doubles digoxin levels) 4
• Other rate-control agents: Reduce beta-blockers and calcium channel blockers as amiodarone's rate-control effect develops 4

Special Populations

Pediatric Dosing

• Rapid bolus: 5 mg/kg IV/IO (maximum 300 mg) 2
• May repeat up to total daily dose of 15 mg/kg 2
• Defibrillator must be immediately available 2

Contraindications

• Second- or third-degree AV block without pacemaker 2
• Sick sinus syndrome or severe sinus node dysfunction without pacemaker 2
• Heart transplant recipients 2

Common Pitfalls to Avoid

• Do not use drop counter infusion sets - they underdose by up to 30% 3
• Do not infuse concentrations >2 mg/mL peripherally for >1 hour 2, 3
• Do not forget to adjust warfarin and digoxin when transitioning to oral 4
• Do not use plastic containers in series - risk of air embolism 3
• Amiodarone has extremely long half-life (IV: 9-36 days; Oral: 26-107 days), so effects and toxicity can be delayed 1