What is the recommended method of administration for injection amiodarone (antiarrhythmic medication)?

Method of Administration for Intravenous Amiodarone

Administer IV amiodarone through a central venous catheter whenever possible using a volumetric infusion pump with an in-line filter, diluted in D5W at concentrations not exceeding 2 mg/mL for peripheral access or infusions longer than 1 hour. 1

Route and Access Requirements

• Use a central venous catheter dedicated to amiodarone administration whenever possible to minimize the risk of severe peripheral vein phlebitis, which occurs frequently with concentrations >2 mg/mL 1
• For concentrations >2 mg/mL, a central line is mandatory 2
• Peripheral venous access may be used only if concentrations are ≤2 mg/mL and infusion duration is ≤1 hour 1

Infusion Equipment and Preparation

• Amiodarone must be delivered by a volumetric infusion pump - never use drop counter infusion sets, as altered surface properties can reduce drop size and cause up to 30% underdosing 1
• Use an in-line filter during all administrations 1
• Administer infusions exceeding 2 hours in glass or polyolefin bottles containing D5W only 1
• Do not use evacuated glass containers for admixing, as buffer incompatibility may cause precipitation 1

Standard Dosing Protocol for Life-Threatening Ventricular Arrhythmias

Initial Loading (First 24 Hours)

• Loading dose: 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min for the remaining 18 hours (total ~1000 mg over 24 hours) 2, 1
• Do not exceed an initial infusion rate of 30 mg/min 1
• Mean daily doses above 2100 mg are associated with increased risk of hypotension 1

Maintenance Infusion (After 24 Hours)

• Continue at 0.5 mg/min (720 mg per 24 hours) using concentrations of 1-6 mg/mL 1
• Maintenance infusion up to 0.5 mg/min can be continued for 2-3 weeks regardless of age, renal function, or left ventricular function 1

Breakthrough Arrhythmias

• For breakthrough VF or hemodynamically unstable VT: administer 150 mg supplemental bolus mixed in 100 mL D5W infused over 10 minutes 1

Cardiac Arrest Protocol (VF/Pulseless VT)

• For cardiac arrest unresponsive to defibrillation and epinephrine: 300 mg IV/IO bolus over 10 minutes, with a second 150 mg bolus if rhythm persists 2
• In pediatric patients: 5 mg/kg rapid bolus (maximum 300 mg) IV/IO, may repeat up to total daily dose of 15 mg/kg 3

Critical Monitoring Requirements

• Continuous ECG monitoring is mandatory during all amiodarone administration to detect bradycardia (occurs in 4.9% of IV patients), AV block, heart block, QT prolongation, and hypotension (occurs in 16% of IV patients) 2, 4
• A defibrillator must be immediately available 3
• Monitor blood pressure continuously during loading doses 2
• Watch for phlebitis at infusion site, particularly with peripheral access 2

Absolute Contraindications

• Do not administer without a pacemaker in patients with: second- or third-degree AV block, sick sinus syndrome, or severe sinus node dysfunction 3, 4
• Contraindicated in patients who have had a heart transplant 3

Important Administration Caveats

• Amiodarone adsorbs to PVC tubing, but all clinical dosing recommendations account for this effect 1
• The drug leaches plasticizers (DEHP) from IV tubing, particularly at higher concentrations and lower flow rates 1
• Amiodarone does not require light protection during administration 1
• Inspect solution before administration - it should be clear 1
• Never use plastic containers in series connections, as this can cause air embolism 1

Common Pitfalls to Avoid

• Loading infusions at concentrations and rates much higher than recommended have resulted in hepatocellular necrosis, acute renal failure, and death 1
• Concentrations >3 mg/mL in D5W are associated with high incidence of peripheral vein phlebitis 1
• If bradycardia or heart block develops, discontinue the infusion or reduce the rate immediately 4
• Reduce digoxin dose by 50% when starting amiodarone, as digoxin levels predictably double 4
• Reduce warfarin dose by 30-50% and check INR within 3-5 days, as amiodarone significantly increases anticoagulation effects 4