Medications for Arrhythmia

woman researching her prescription on tablet

When taken exactly as prescribed, medications can do wonders. They can help prevent heart attack and stroke. They can also prevent complications and slow the progression of coronary heart disease.

Some of the commonly prescribed medications used to treat arrhythmias are summarized in this section. It's important to discuss all the drugs you take with your health care team. It's important to understand how they work and the possible side effects. Never stop taking a medication and never change your dose or frequency without first talking to your health care professional.

Antiarrhythmic drugs

Symptomatic tachycardias and premature beats may be treated with a variety of medications. These may be given intravenously in an emergency or orally for long-term treatment. These drugs either lessen the abnormal signals from the sinus node or inhibit the movement of signals in the heart tissue that may conduct too fast or allow signals to re-enter.

In patients with atrial fibrillation, a *blood thinner (anticoagulant or antiplatelet) is usually added to reduce the risk of blood clots and stroke. Learn more about AFib medications.

When tachycardias or premature beats occur often, the effectiveness of antiarrhythmic drug therapy may be gauged by electrocardiographic (ECG) monitoring in a hospital, by using a 24-hour Holter monitor or by serial evaluation with electrophysiologic testing.

The use of antiarrhythmic drug therapy must be balanced against two disadvantages. One is that the drugs must be taken daily and indefinitely. The other is the risk of side effects. While side effects are a risk of all medication, those associated with antiarrhythmic drugs can be very hard to manage. One such side effect is proarrhythmia, the more-frequent occurrence of preexisting arrhythmias or the appearance of new arrhythmias.

Calcium channel blockers

Calcium channel blockers, also known as "calcium antagonists," work by interrupting the movement of calcium into heart and blood vessel tissue. Besides being used to treat high blood pressure, they're also used to treat angina (chest pain) and/or some abnormal heart rhythms.

Beta blockers

Beta blockers decrease the heart rate and cardiac output, which lowers blood pressure by blocking the effects of adrenalin. They're also used with therapy for cardiac arrhythmias and in treating angina pectoris.


Anticoagulants (blood thinners) work by making it harder for the blood to clot or coagulate. They aren't designed to dissolve existing blood clots. They prevent new clots from forming or existing clots from getting larger. Because a common type of stroke is caused by a blood clot obstructing blood flow to the brain, anticoagulants are often prescribed for people with certain conditions to prevent a first stroke or to prevent recurrence of a stroke. Anticoagulants are also given to people at risk for forming blood clots, such as those with artificial heart valves or who have atrial fibrillation.

Taking medications

  • Take all medications exactly as prescribed.
  • Never stop taking any prescription medication without first consulting your health care professional.
  • Tell your health care professional about any side effect you have.
  • Tell your health care team about all your other drugs and supplements, including over-the-counter medications, herbs and vitamins.
  • Many rhythm disorders, especially tachycardias, respond to medications. These medicines can't cure the arrhythmia, but they can improve symptoms. They do this by preventing the episodes from starting, decreasing the heart rate during the episode or shortening how long it lasts.
  • Sometimes it's hard to find the best medication for a child. Several drugs may need to be tried before the right one is found. Some children must take medication every day; others need medications only when they have a tachycardia-type episode. It's very important to take the medication as prescribed.
  • All medications have side effects, including drugs to treat arrhythmias. Most of the side effects aren't serious and disappear when the dose is adjusted or the medication is stopped. But some side effects are very serious. That's why some children are admitted to the hospital to begin the medication. If your child is prescribed medication, it's very important that your child takes it exactly as prescribed.
  • It's often necessary to monitor how much of a drug is in your child's blood. The goal is to make sure there's enough of the drug to be effective, but not so much that harmful side effects occur. These blood tests require taking a small amount of blood from a vein or the finger. It's a good idea to talk to your child about this before the doctor visit.

* Some medications are commonly called blood thinners because they can help reduce a blood clot from forming. There are two main types of blood thinners that patients commonly take: anticoagulants such as warfarin, dabigatran (Eliquis) and rivaroxaban (Xarelto), and antiplatelet drugs such as aspirin or clopidogrel. Each type of medication has a specific function to prevent a blood clot from forming or causing a blocked blood vessel, heart attack or stroke.