Last reviewed 2026-04-20 · How we verify

Cordarone (AMIODARONE)

Amiodarone, a class III antiarrhythmic, blocks sodium, potassium, and calcium channels, prolongs cardiac action potentials, and has vasodilatory effects.

Cordarone (Amiodarone) is a small molecule antiarrhythmic medication originally developed by Wyeth Pharms Inc and currently owned by the same company. It targets 3-beta-hydroxysteroid-Delta(8),Delta(7)-isomerase and is FDA-approved for the treatment of life-threatening ventricular tachycardia, prevention of ventricular fibrillation, and ventricular fibrillation. Cordarone is off-patent and has multiple generic manufacturers. Key safety considerations include its long half-life of 820 hours and bioavailability of 50%. It is essential to monitor patients for potential side effects, such as thyroid dysfunction and pulmonary fibrosis.

At a glance

Mechanism of action

Amiodarone works by affecting the electrical activity of the heart. It blocks various ion channels, which helps to stabilize heart rhythms by slowing down the conduction of electrical signals and making the heart less likely to beat irregularly. Additionally, it dilates blood vessels, reducing the workload on the heart and lowering oxygen demand.

Approved indications

• Life-Threatening Ventricular Tachycardia
• Prevention of Ventricular Fibrillation
• Ventricular fibrillation

Boxed warnings

• WARNING: PULMONARY, HEPATIC and CARDIAC TOXICITY Pacerone is intended for use only in patients with the indicated life-threatening arrhythmias because its use is accompanied by substantial toxicity [see Indications and Usage (1) ] . Pacerone can cause pulmonary toxicity (hypersensitivity pneumonitis or interstitial/alveolar pneumonitis) that has resulted in clinically manifest disease at rates as high as 17% in some series of patients. Pulmonary toxicity has been fatal about 10% of the time . Obtain a baseline chest X-ray and pulmonary-function tests, including diffusion capacity, when Pacerone therapy is initiated. Repeat history, physical exam, and chest X-ray every 3 to 6 months [see Warnings and Precautions 5.2) ] . Pacerone can cause hepatoxicity, which can be fatal. Obtain baseline and periodic liver transaminases and discontinue or reduce dose if the increase exceeds three times normal, or doubles in a patient with an elevated baseline. Discontinue Pacerone if the patient experiences signs or symptoms of clinical liver injury [see Warnings and Precautions (5.3) ] . Pacerone can exacerbate arrhythmias. Initiate amiodarone hydrochloride in a clinical setting where continuous electrocardiograms and cardiac resuscitation are available [see Warnings and Precautions (5.4) ] . WARNING: PULMONARY, HEPATIC, and CARDIAC TOXICITY See full prescribing information for complete boxed warning. Reserve Pacerone for patients with the indicated life-threatening arrhythmias because its use is accompanied by substantial toxicity, some also life-threatening. Utilize alternative agents first. ( 1 ) Pacerone' s life-threatening toxicities include pulmonary ( 5.2 ), hepatic ( 5.3 ), and proarrhythmic ( 5.4 ). Initiate under hospital or specialist supervision. ( 5 )

Common side effects

• Pulmonary infiltrates or fibrosis
• Paroxysmal ventricular tachycardia
• Congestive heart failure
• Elevation of liver enzymes
• Visual disturbances
• Solar dermatitis
• Blue skin discoloration
• Hyperthyroidism
• Hypothyroidism
• Nausea and vomiting
• Dermatologic: Solar dermatitis/photosensitivity
• Bradycardia

Drug interactions

• High Risk QT Prolonging Agents
• P-glycoprotein Substrates
• abarelix
• anisindione
• apomorphine
• arsenic trioxide
• astemizole
• atazanavir
• atorvastatin
• azithromycin
• chloroquine
• chlorpromazine

Key clinical trials

• Non-Invasive Programmed Stimulation (NIPS) to Guide the Subsequent VT Therapeutic Strategies (NA)
• Comparative Efficacy of 100-, 200-, & 400-mg Amiodarone in Patients With Paroxysmal AF Depending on Plasma Concentration (PHASE4)
• The PIVATAL Study -Study of Ventricular Arrhythmia (VTA) Ablation in Left Ventricular Assist Device (LVAD) Patients (PHASE4)
• Pragmatic Amiodarone Trial to Reduce Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery (PHASE4)
• Catheter Ablation Versus Anti-arrhythmic Drugs for Ventricular Tachycardia (NA)
• Pharmacokinetics of Amiodarone in Children (NA)
• Role of Combination Therapy of Glucose Insulin Potassium Infusion (GIK), Intravenous Hydrocortisone and Oral Sevelamer in Treatment of Acute Aluminum Phosphide Poisoned Cases Admitted to Intensive Care Unit (ICU) at Sohag University Hospitals. (NA)
• Efficacy of Early Rhythm Control Therapy in Patients With Subclinical Atrial Fibrillation (NA)

Primary sources

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