Amiodarone tablets are used in the management of various serious cardiac arrhythmias, including ventricular fibrillation, ventricular tachycardia, atrial fibrillation, and atrial flutter.

Amiodarone injection is indicated for the initiation of therapy and prevention of recurrent ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT) in patients who do not respond adequately to other treatments.

Amiodarone Hydrochloride is used to control abnormal heart rhythms and is regarded as a broad-spectrum antiarrhythmic agent. Its primary electrophysiological actions include prolongation of the cardiac repolarization phase, which delays the recovery of the heart’s electrical system after each contraction. It also extends the duration of the action potential in cardiac muscle cells. Additionally, it slows electrical conduction through the heart, reduces the firing rate of the natural pacemaker, and inhibits conduction through accessory pathways. Apart from its antiarrhythmic properties, Amiodarone causes vasodilation, which may be beneficial in patients with congestive heart failure. However, this effect may also lead to a reduction in blood pressure.

Tablet: 200 mg 3 times daily for 1 week reduced to 200 mg twice daily or the minimum required to control arrhythmia. Amiodarone is usually given in several daily doses to minimize stomach upset which is seen more frequently with higher doses. For this same reason, it is also recommended that Amiodarone should be taken with meals.

Injection: The recommended starting dose is about 1000 mg over the first 24 hours of therapy, delivered by the following infusion regimen:

• Initial Load: 150 mg per 100 mL (in D5W or Normal Saline) infused over 10 minutes
• Followed by: 1 mg/min for 6 hours
• Followed by: 0.5 mg/min thereafter

In the event of breakthrough episodes of VF or hemodynamically unstable VT: Repeat the Initial Load described above as needed (infused over 10 minutes). Increase the rate of maintenance infusion to achieve effective arrhythmia suppression.

Amiodarone may interact with beta-blockers such as atenolol, propranolol, and metoprolol, as well as calcium channel blockers like verapamil and diltiazem, potentially leading to excessive slowing of heart rate. It increases serum levels of digoxin when used concurrently. Plasma concentrations of flecainide may rise by more than 50%, while procainamide and quinidine levels may increase by 30–50% during the initial phase of therapy. Amiodarone may also interact with tricyclic antidepressants (TCAs). When used with warfarin, it enhances the risk of bleeding. Additionally, it inhibits the metabolism of dextromethorphan.

Amiodarone is contraindicated in patients with cardiogenic shock, severe sinus node dysfunction causing marked bradycardia, second- or third-degree atrioventricular block, or a history of syncope due to bradycardia (unless a pacemaker is present). It is also contraindicated in patients with known hypersensitivity to amiodarone, iodine, or any of its components.

Serious adverse effects primarily involve the lungs and may be life-threatening. Patients should report symptoms such as cough, fever, or painful breathing. Rarely, severe liver toxicity may occur. Other effects include corneal deposits (sometimes causing night glare), visual disturbances due to optic neuritis, peripheral neuropathy, and muscle weakness (usually reversible). Cardiac effects such as bradycardia and conduction abnormalities may occur. Skin reactions include photosensitivity and, rarely, persistent discoloration. Thyroid dysfunction (both hypo- and hyperthyroidism), elevated liver enzymes, jaundice, hepatitis, and cirrhosis have been reported. Additional side effects may include nausea, vomiting, metallic taste, tremor, sweating, dizziness, headache, insomnia, fatigue, hair loss, increased intracranial pressure, ataxia, rashes, vasculitis, renal complications, thrombocytopenia, and various types of anemia. Dose reduction or discontinuation may be required in some cases.

Amiodarone is generally not recommended during pregnancy due to reports of thyroid dysfunction in infants exposed during gestation. If its use is essential, the potential risk to the fetus should be explained. The safety of Amiodarone during breastfeeding has not been established.

Potassium channel blockers

Store below 30°C, protected from light and moisture. Keep out of reach of children.