The Effects of Amiodarone:
Amiodarone can prolong AV conduction, the AV refractory period, and QRS and QT intervals—ultimately slowing the heart rate. Amiodarone is a well known multi channel blocker, because it blocks sodium, potassium, and calcium channels and is an alpha and beta blocker.
Amiodarone Indications for Use:
Amiodarone is an antiarrhythmic drug. It is specifically used for its broad range of electrophysiologic effects.
Amiodarone is primarily chosen for ACLS as the first-line antiarrhythmic agent for cardiac arrest. This is because it is effective in improving the rate of return of spontaneous circulation (ROSC) and improved ROSC to hospital admission in adults with refractory v-fib or pulseless v-tach.
Amiodarone may be considered when v-fib and v-tach is unresponsive to CPR, defibrillation, and epinephrine.
Amiodarone Precautions & Contraindications:
With amiodarone, there are multiple complex drug interactions, so caution must be used when administering this drug.
Rapid infusion may lead to hypotension. But since there is no blood pressure during cardiac arrest, the American Heart Association still recommends rapid IV push for antiarrhythmic treatment.
Significant hypotension has been noted in clinical trials when multiple doses of Amiodarone are used. Multiple doses could be a cumulative dose of greater than 2.2 g over 24 hours.
Amiodarone should not be administered with other drugs that prolong QT interval, such as procainamide.
Terminal elimination of amiodarone is extremely long. As a result, amiodarone can be complicated to work around when treating a patient who has experienced return of spontaneous circulation, as one may not be able to use certain other medications until amiodarone has been effectively eliminated from the patient’s body.
Adult Dosage for Amiodarone:
When using amiodarone to treat ventricular fibrillation or pulseless ventricular tachycardia, the first dose should be 300 mg IV/IO push. The second dose is delivered at 150mg IV/IO push.
Rapid Infusion:
- For life threatening arrhythmias, the maximum cumulative dose is 2.2g IV over 24 hours
- For patients with a pulse but who are suffering life threatening arrhythmias, amiodarone should be given by rapid infusion delivered 150 mg IV over the first 10 minutes, equally 15 mg per minute
- Rapid infusion may be repeated every 10 minutes as needed up to a total of 2.2 g in 24 hours
Slow Infusion:
- To give amiodarone by slow infusion, 360 mg IV should be delivered over 6 hours, or 1 mg per minute
- The maintenance infusion is 540 mg IV over 18 hours, which is .5 mg per minute
These infusions must not exceed 2.2 g in a 24 hour period. When delivered in this amount, its effects can last upwards of 40 days.