Classes
DEA Class; Rx
Common Brand Names; Pacerone, Cordarone, Nexterone
- Antidysrhythmics, III
Description
Class III antiarrhythmic agent
Used for ventricular and supraventricular tachyarrhythmias
Risk of proarrhythmias less than other antiarrhythmics
Indications
Indicated for the treatment of life-threatening recurrent ventricular fibrillation or hemodynamically unstable (symptomatic) sustained ventricular tachycardia, including post-myocardial infarction (MI) patients.
Contraindications
Hypersensitivity
Severe sinus node dysfunction, 2°/3° AV block or bradycardia causing syncope (except with functioning artificial pacemaker), cardiogenic shock
Avoid during breastfeeding
Adverse Effects
- Increased liver AST or ALT levels (3-20%; as high as 40-50% in some studies)
- Hypotension (16%)
- Dizziness (3-40%)
- Headache (3-40%)
- Malaise (3-40%)
- Abnormal gait/ataxia (3-40%)
- Fatigue (3-40%)
- Impaired memory (3-40%)
- Involuntary movement (3-40%)
- Sleep disturbances (3-40%)
- Photosensitivity (10-75%)
- Hypothyroidism (1-22%)
- Constipation (10-33%)
- Anorexia (10-33%)
- CHF (3%)
- Bradycardia or sinus arrest (3-5%)
- AV block (5%)
- SA node dysfunction (1-3%)
- Hyperthyroidism (3-10%)
- Hepatitis and cirrhosis (<3%)
- Visual disturbances (2-9%)
- Optic neuritis (1%)
- Corneal microdeposits
- Demyelinating polyneuropathy
Warnings
To be administered only by physicians experienced in treatment of life-threatening arrhythmias, who are thoroughly familiar with risks and benefits of amiodarone therapy, and have access to facilities adequate for monitoring effectiveness and side effects of treatment; because of long half-life of amiodarone and its metabolite desethylamiodarone, the potential for adverse reactions or interactions, as well as observed adverse effects, can persist following amiodarone withdrawal
Adjust dosage based on adverse reaction and therapeutic response
Avoid excessive exposure to sunlight; may cause photosensitivity
Infusion site phlebitis has occurred in patients receiving intravenous amiodarone; intravenous amiodarone concentrations greater than 3 mg/mL associated with a high incidence of peripheral vein phlebitis
Attempts to substitute other antiarrhythmic agents when amiodarone must be stopped is difficult due to the complex pharmacokinetics of the drug, including prolonged duration of action and half-life and difficulties predicting them, which in turn increases risk for drug interactions
Hypothyroidism has been reported in 2 to 10% of patients receiving amiodarone and may be primary or subsequent to resolution of preceding amiodarone-induced hyperthyroidism; manage hypothyroidism by reducing the dose of or discontinuing amiodarone and considering the need for thyroid hormone supplement
Risks of acute MI, AV block, cardiomegaly; especially with IV administration
Pregnancy and Lactation
Amiodarone can cause fetal harm when administered to a pregnant woman; fetal exposure may increase potential for adverse experiences including cardiac, thyroid, neurodevelopmental, neurological and growth effects in neonate; inform patient of potential hazard to fetus if amiodarone administered during pregnancy or if patient becomes pregnant while in therapy
Amiodarone and one of its major metabolites, DEA, are excreted in human milk, suggesting that breast-feeding could expose the nursing infant to a significant dose of the drug; risk of exposing infant to amiodarone and DEA must be weighed against potential benefit of arrhythmia suppression in the mother; advise mother to discontinue nursing
Maximum Dosage
No specific maximum dosage guidelines are available. Amiodarone dosage is individualized according to clinical goals, phase of dosage titration, and close monitoring of efficacy and safety parameters.
How supplied
Amiodarone hydrochloride
injectable solution
- 50mg/mL
- 150mg/100mL (Nexterone)
- 360mg/200mL (Nexterone)
tablet
- 100mg
- 200mg
- 400mg
