【藥品性質提示】 根據 2019 AGS Beers Criteria，本藥品為【潛在不適當用藥 (PIM)】，不建議用於老年人第一線治療。

治療心律不整
1. Life-threatening recurrent ventricular fibrillation and tachycardia that has been unresponsive to adequate dose of other antiarrhythmic agents.
2. Refractory supraventricular arrhythmias.

Antiarrhythmic drug with predominant class III effects of lengthening cardiac action potential and blocking myocardial potassium channels leading to slowed conduction and prolonged refractoriness.

Absorption:
1. Time to peak concentration: 3 to 7 hr
2. Bioavailability: approximately 50% (35% to 65%)
Distribution:
1. Vd: about 60 L/kg
2. Protein binding: approximately 96%
Metabolism:
Hepatic: P450 CYP3A4 and CYP2C8
Excretion:
1. Bile: primary excretion site
2. Renal: negligible amount (less than 1%)
3. Dialyzable: no
Elimination Half Life:
26 to 107 day

1. Bradycardia, impairment of A-V conduction, heart failure
2. Patient with iodine sensitivity, disorders of the thyroid gland
3. Do not expose to sunlight
4. Can't be used with MAO inhibitors, beta-blockers or calcium antagonists

D/C in controversy

Avoided, amiodarone present significant concentration in breast milk. An accumulation of this drug in the lung and liver has been reported. Also each 200mg of amiodarone contains 75mg of iodine.

Common:
Benign yellowish-brown corneal microdepositis, photosensitivity, severe bradycardia, conduction disturbances, hypotension, hypo- or hyperthyroidism, peripheral neuropathy, tremor, ataxia, paresthesia, anorexia, nausea, vomiting, constipation, nightmares, and fatigue.
Common adverse effects requiring discontinuance:
pulmonary infiltrates or fibrosis, paroxysmal ventricular tachycardia, congestive heart failure, and elevations of serum hepatic enzyme concentrations.

Initial dose: 800-1600 mg PO daily for 1-3 weeks.
After adequate control: 600-800 mg daily for one month then 400 mg daily.