List of products in the National Drug Code with proprietary name . This medication is used to treat certain types of serious (possibly fatal) irregular heartbeat (such as persistent ventricular fibrillation/tachycardia). It is used to restore normal heart rhythm and maintain a regular, steady heartbeat. Amiodarone is known as an anti-arrhythmic drug. It works by blocking certain electrical signals in the heart that can cause an irregular heartbeat.