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Updated July 2026 · 9 min read

This article was created with AI assistance.

Amiodarone: The ICU Nurse's Guide

⚕️ Medical Disclaimer: This content is for educational purposes only and is intended for licensed healthcare professionals. It does not constitute medical advice and should not replace clinical judgment, facility protocols, or physician orders. Always verify medications, doses, and procedures with your institution's guidelines.

Part of the ICU Pharmacology Hub — browse every related guide in one place.

Amiodarone is the antiarrhythmic you will hang for everything from a pulseless VT arrest to a patient in rapid atrial fibrillation. It is powerful and broad-spectrum, but it is unforgiving if pushed too fast and famously toxic over the long haul. Here is the practical picture.

The short version: Amiodarone is a broad-spectrum antiarrhythmic (technically Class III but with Class I, II, and IV effects). In cardiac arrest from VF/pulseless VT, the ACLS dose is 300 mg IV push, then 150 mg. For a patient with a pulse (stable VT, atrial fibrillation), it is a 150 mg load over 10 minutes, then an infusion (1 mg/min for 6 hours, then 0.5 mg/min). Push it too fast in a patient with a pulse and you cause hypotension and bradycardia; run it long and it carries serious pulmonary, thyroid, and hepatic toxicity.

How amiodarone works

Amiodarone blocks potassium channels (prolonging repolarization and the QT interval), but it also blocks sodium and calcium channels and has beta-blocking properties. This multi-channel action makes it effective against both ventricular and supraventricular arrhythmias, which is why it is one of the most-used antiarrhythmics in the ICU. The same QT prolongation, however, is why you monitor the ECG and electrolytes closely.

Dosing: arrest vs pulse

ScenarioDose
VF / pulseless VT (ACLS)300 mg IV push; second dose 150 mg
Stable VT / AF (loading)150 mg IV over 10 min
Maintenance infusion1 mg/min × 6 hr, then 0.5 mg/min × 18 hr
BreakthroughSupplemental 150 mg over 10 min per order
Bedside rule of thumb: The difference between a rapid push and a slow infusion is the difference between the pulseless patient and the one with a pulse. In arrest, you push it fast. In a perfusing patient, pushing amiodarone quickly drops the blood pressure — always give the loading dose over the ordered time.

Acute effects to watch

Hypotension. The most common acute adverse effect, related to infusion rate and the diluent. Slow the infusion and support the pressure per orders.

Bradycardia and AV block. Its beta- and calcium-blocking effects can slow the rate excessively, especially combined with other AV nodal agents.

Phlebitis. Concentrated amiodarone irritates veins. Infusions beyond a short duration or above a certain concentration should run through a central line, and an in-line filter is often required. Watch peripheral sites closely.

QT prolongation. Monitor the QT and correct potassium and magnesium; the torsades risk is real when combined with other QT-prolonging drugs.

Long-term toxicity — the reason amiodarone is respected

Amiodarone is one of the most toxic drugs in chronic use. It accumulates in tissues and has an extraordinarily long half-life (weeks to months). Long-term concerns include pulmonary toxicity (potentially fatal pulmonary fibrosis/pneumonitis — watch for new cough or dyspnea), thyroid dysfunction (both hypo- and hyperthyroidism, because the molecule is iodine-rich), hepatotoxicity (monitor LFTs), corneal deposits, blue-gray skin discoloration, and optic neuropathy. Patients on chronic amiodarone need baseline and periodic pulmonary, thyroid, liver, and eye monitoring. For the ICU nurse, the takeaway is to flag new respiratory symptoms and abnormal thyroid or liver labs in any patient on the drug.

Drug interactions

Amiodarone raises levels of several drugs. Two to know cold: it potentiates warfarin (bleeding risk — the INR climbs) and raises digoxin levels (toxicity). It also interacts with many other agents metabolized by the liver. Any patient starting amiodarone who is also on warfarin or digoxin needs dose review and closer monitoring.

Why CRNA students should know it

On the CRNA path, amiodarone is a code-cart and perioperative arrhythmia drug you must know for ACLS and for managing intraoperative ventricular and atrial arrhythmias. Understanding its multi-channel mechanism, the arrest-versus-pulse dosing split, and its hemodynamic and toxicity profile at the ICU bedside is exactly what you will apply in anesthesia emergencies.

Bottom line

Amiodarone is the broad-spectrum antiarrhythmic: 300 then 150 in arrest, load-then-drip with a pulse, hypotension if pushed fast, central line for prolonged infusion, and a long list of chronic toxicities that make monitoring essential. Respect the infusion rate, watch the QT and electrolytes, and flag warfarin and digoxin interactions. Learn it now and it carries into anesthesia practice.

Related pharmacology: pair with the vasopressor guide for the hypotension that can accompany it, and the diltiazem drip guide for rate control in atrial fibrillation.

This article is general educational information for licensed clinicians and students, not medical advice or a substitute for your institution's protocols, pharmacy guidance, or a provider's orders. Always follow facility policy and verify every dose independently.

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