Antiarrhythmic medications for fast heart rates

Antiarrhythmic medicines work in various ways to return the heart to its normal rhythm. These medicines stabilize heart rhythm by decreasing abnormal firing of the heart's electrical system that causes the heart to beat too fast or by slowing the electrical conduction through abnormal pathways. Some antiarrhythmics also slow the heart rate by reducing the number of impulses that can pass through the atrioventricular (AV) node (amiodarone, sotalol).

Antiarrhythmic medicines are used to change an abnormal heart rhythm to a regular rhythm and to prevent an abnormal heart rhythm.

Antiarrhythmic medicines can effectively control or prevent abnormal heart rhythms. There are many different types of antiarrhythmic medicines. You may need to try different medicines to see which one works best for you.

Some antiarrhythmic medicines may increase the risk of developing a more rapid, abnormal heart rate problem (ventricular tachycardia or ventricular fibrillation), especially for those people with a poorly functioning left ventricle. Close monitoring while taking these medicines is important.

Side effects of antiarrhythmics include:

• Chest pain.
• Slow heartbeat.
• Palpitations.
• Fatigue.
• Headache.
• Dizziness.
• Nausea and vomiting.
• Unusual taste in the mouth.
• Stomach pain.
• Constipation or diarrhea.
• Difficulty breathing.
• Rash.
• Vision problems.
• Urinary retention in men.
• Blue tinge to the skin (with amiodarone).

The FDA recently issued warnings about the medicine amiodarone (Cordarone). People taking this medicine should be aware that it may cause serious side effects that can lead to death, including lung damage, liver damage, and more severe heartbeat problems. Amiodarone is typically used for people who have severe symptoms when other medicines have failed. The FDA recommends that you talk to your doctor if you have any side effects or any concerns about taking amiodarone.¹

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

You should learn to take your pulse if you are taking an antiarrhythmic medicine. Notify your doctor if your heart rhythm becomes too slow (less than 50 beats per minute) or irregular while you are taking an antiarrhythmic medicine.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

1. U.S. Food and Drug Administration (2005). 2005 safety alert: Cordarone (amiodarone HCl). FDA Med Watch. Available online: http://www.fda.gov/medwatch/SAFETY/2005/cordarone_DHCP.htm.