Amiodarone

Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of irregular heartbeats.

Amiodarone

Amiodarone, Amiodarona, Cordarone, Amiodaronum, Amjodaronum

Aldarone, Biodaron, Cardasol, Duron, Eurythmic, Panaron, Ritebeat, Tachyra, Amiodar, Amiodon, Amipace, Cardichek, Cordarone, Cordarone-X.

{2-[4-(2-butyl-1-benzofuran-3-carbonyl)-2,6 diiodophenoxy]ethyl}diethylamine

• Absorption: Slowly and variably absorbed after oral administration
• Distribution: >96%
• Metabolism: Amiodarone is extensively metabolized in the liver via CYP2C8
• Excretion: It is eliminated primarily by hepatic metabolism and biliary excretion and there is negligible excretion of amiodarone or DEA in urine.

It is Class III antiarrhythmic agents, used in the treatment of a wide range of cardiac tachyarrhythmia’s, including both supraventricular and ventricular arrhythmias. After IV administration in man, amiodarone relaxes vascular smooth muscle, reduces peripheral vascular resistance (afterload), and slightly increases cardiac index. The antiarrhythmic effect of amiodarone may be due to at least two major actions. It prolongs the myocardial cell-action potential (phase 3) duration and refractory period and acts as a noncompetitive a- and b-adrenergic inhibitor.

• 800-1,600 mg/day in 1-2 divided doses for 1-3 weeks until initial therapeutic response is achieved, then reduce dose to 600-800 mg/day in 1-2 divided doses for 1 month for Ventricular arrhythmias through oral route of administration.
• Recommended starting dose: About 1 g over 1st 24 hr. Dose is given in a 3-phase sequence for Life-threatening ventricular arrhythmias via IV route.

Ventricular arrhythmia and ventricular tachycardia.

Pulmonary toxicity including pulmonary fibrosis and interstitial pneumonitis, hepatotoxicity, thyrotoxicity. Blue-grey discolouration of skin, photosensitivity, paraesthesia, peripheral neuropathy, ataxia, myopathy, nausea, tremor, vomiting, hypothyroidism, metallic taste, hyperthyroidism, alopoecia, sleep disturbances, corneal microdeposits, hot flushes, sweating.

• Possible increased risk of adverse effects when used with anaesthetic agents.
• Cimetidine may increase serum levels of amiodarone.
• Monitor plasma levels of amiodarone when used with HIV protease inhibitors. 
• Concurrent use may increase serum levels of ciclosporin.
• Rifampin may reduce the serum levels of amiodarone.
• May increase risk of myopathy or rhabdomyolysis when used with HMG-CoA reductase inhibitors.
• Grapefruit juice may increase serum levels of amiodarone.

• Teratogenic Effects 
• Pregnancy category D
• Neonatal Hypo- or Hyperthyroidism
• Amiodarone hydrochloride tablets are contraindicated in patients with cardiogenic shock, severe sinus-node dysfunction, causing marked sinus bradycardia, in patients with a known hypersensitivity to the drug or to any of its components, iodine, second- or third-degree atrioventricular block and when episodes of bradycardia have caused syncope.

• Oral: Store at 20-25°C.
• Intravenous: Store at 15-25°C.

Molecular weight

645.3116

Molecular formula

C25H29I2NO3

CAS number

1951-25-3

Precautions

Close monitoring is recommended as amiodarone may worsen arrhythmia especially when used concurrently with other anti-arrhythmic drugs or drugs that prolong QT interval. May cause hypotension and bradycardia. May increase risk of liver toxicity. Avoid excessive sunlight exposure due to increased risk of photosensitivity.