Because of its life-threatening side effects and the substantial management difficulties associated with its use, Amiodarone is indicated only for the treatment of the following documented, life threatening recurrent ventricular arrhythmias when these have not responded to documented adequate doses of other available antiarrhythmics or when alternative agents could not be tolerated. Recurrent ventricular fibrillation. Recurrent hemodynamically unstable ventricular tachycardia. As is the case for other antiarrhythmic agents, there is no evidence from controlled trials that the use of Amiodarone Tablets favorably affects survival. Amiodarone should be used only by physicians familiar with and with access to (directly or through referral) the use of all available modalities for treating recurrent life threatening ventricular arrhythmias, and who have access to appropriate monitoring facilities, including in-hospital and ambulatory continuous electrocardiographic monitoring and electrophysiologictechniques. Because of the life-threatening nature of the arrhythmias treated, potential interactions with prior therapy, and potential exacerbation of the arrhythmia, initiation of therapy with Amiodarone should be carried out in the hospital.
Potassium channel blockers
Amiodarone Hydrochloride is used to correct abnormal rhythms of the heart. Amiodarone is considered a "broad spectrum" antiarrhythmic medication. The most important electrical effects of the drug includes : a delay in the rate at which the heart’s electrical system "recharges" after the heart contracts (repolarisation); a prolongation in the electrical phase during which the heart’s muscle cells are electrically stimulated (action potential); a slowing of the speed of electrical conduction (how fast each individual impulse is conducted through the heart’s electrical system); a reduction in the rapidity of firing of the normal generator of electrical impulses in the heart (the heart’s pacemaker); and a slowing of conduction through various specialised electrical pathways (called accessory pathways). In addition to being an antiarrhythmic medication, Amiodarone also causes blood vessels to dilate. Because of this effect it also may be of benefit in patients with congestive heart failure. This effect can result in drop of blood pressure.
Oral dose is 200 mg 3 times daily for 1 week reduced to 200 mg twice daily or the minimum required to control arrhythmia.
Amiodarone may interact with b blockers such as Atenolol, Propranolol, Metoprolol, or certain calcium channel blockers, such as Verapamil or Diltiazem, resulting in an excessively slow heart rate. Amiodarone increases the blood levels of Digoxin when the two drugs are given together. Flecainide blood concentrations increase by more than 50% with Amiodarone. Procainamide and Quinidine concentrations increase by 30-50% during the first week of Amiodarone therapy. Amiodarone also can interact with tricyclic antidepressants (TCA). Amiodarone interacts with Warfarin and increases the risk of bleeding. Amiodarone inhibits the metabolism of Dextromethorphan.
Amiodarone is contraindicated in patients with cardiogenic shock; severe sinus-node dysfunction, causing marked sinus bradycardia; second- or third degree atrioventricular block; and when episodes of bradycardia have caused syncope (except when used in conjunction with a pacemaker). Amiodarone is contraindicated in patients with a known hypersensitivity to the drug or to any of its components, including iodine.
The most severe side effects are any symptoms of cough, fever, or painful breathing, reversible corneal microdeposits, impaired vision due to optic neuritis, peripheral neuropathy, bradycardia and conduction disturbances, phototoxicity and rarely persistent skin discoloration, hypothyroidism, hyperthyroidism, raised serum transaminases, jaundice, hepatitis and cirrhosis etc.
Should not be administered during pregnancy and lactation.
Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.
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