Amiodarone

• Amiodarone

• Cordarone

Classification:

• Class III Antidysrhythmic

Mechanism of Action:

• Prolongs the cardiac action potential and refractory period
• Inhibits alpha and beta-adrenergic stimulation resulting in relaxation of vascular smooth muscle and decreases peripheral vascular resistance
• Class I – blocks Na channels, Class II – Inhibits sympathetic stimulation, Class III – blocks K channels, Class IV- blocks Ca channels (weakly)
• Increases the VF threshold
• Negative chronotropic effects
• Slows conduction through the AV node
• Increases PR & QT intervals 

Indications:

• Refractory VF/pulseless VT
• Polymorphic VT and wide complex tachycardia of unknown origin
• Control of hemodynamically stable VT
• Runs of VT post cardiac arrest

Contraindications:

• Hypersensitivity or known iodine hypersensitivity (iodine makes up a large part of the amiodarone molecule)
• Bradycardia
• 2^nd & 3^rd Degree heart block
• Sinus node dysfunction

Precautions:

• Bradycardia
• Monitor BP may produce vasodilation/ hypotension
• When given with digitalis preparations, may cause digitalis toxicity
• Pulmonary disease
• Hepatic or renal disease
• May prolong QT interval
• Hypokalemia/hypomagnesaemia

Adverse Effects:

• Hypotension
• Headache
• Dizziness
• Bradycardia
• AV conduction abnormalities
• Flushing and abnormal salivation

Dose:

Adult:

• VF/VT Cardiac Arrest: 300 mg IV/IO push then 150 mg IV/IO push after 4 minutes if required.
• VT with a pulse/runs of VT post cardiac arrest: 150 mg IV/IO diluted in 100 mL normal saline and administered over 10 minutes (15 mg/min); repeated q 10 minutes as required.

Pediatric:

• VF/VT Cardiac Arrest: 5 mg/kg IV/IO push (max single dose 300 mg); repeated q 4 minutes as required (maximum total dose (15 mg/kg).
• VT with a pulse/runs of VT post cardiac arrest (with MCCP approval): 5 mg/kg IV diluted in 100 mL normal saline and administered over 20 minutes (maximum single dose 300 mg); repeated q 10 minutes as required (maximum total dose of 15 mg/kg). 

• IV/IO

• Compendium of Pharmaceuticals and Specialties (CPS)
• Pharmacology for the Prehospital Professional 2^nd Edition