Antiarrhythmic Medicines for Fast Heart Rates

Some antiarrhythmic medicines raise your risk of having a dangerous arrhythmia such as ventricular tachycardia or ventricular fibrillation. Your doctor will check you closely while you take these medicines. The risk of side effects might be greater if you have severe heart disease.

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

• Usually the benefits of the medicine are more important than any minor side effects.
• Side effects may go away after you take the medicine for a while.
• If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

Heart symptoms such as:

• New or worse dizziness or lightheadedness.
• Severe heart palpitations.
• Severe weakness.

Severe allergy symptoms such as:

• Trouble breathing.
• Swelling of your face, lips, tongue, or throat, which may occur with hives.

Antiarrhythmic medicines can cause less serious side effects that may go away after taking the medicine for a while. Call your doctor if these side effects continue or if they bother you a lot.

• Stomach problems, such as diarrhea, pain, or nausea.
• Loss of appetite.
• Feeling weak or tired.

Amiodarone

Call your doctor if you have any side effects from amiodarone. Side effects may include:

• Cough or trouble breathing.
• Dizziness, lightheadedness, or fainting.
• Trembling or shaking.
• Weakness in the arms or legs.
• Blurry vision or other vision changes.

Disopyramide

Call your doctor right away if you have:

• Dizziness, lightheadedness, or fainting.
• Change in heartbeat, such as a fast or irregular beat.
• Shortness of breath.
• Unusual tiredness.

Other side effects of disopyramide may include:

• Low blood sugar.
• Blurry vision.
• Dry eyes or mouth.

Dofetilide

Call your doctor right away if you have:

• Dizziness, lightheadedness, or fainting.
• Fast or irregular heartbeat.

Dronedarone

Call your doctor right away if you have symptoms of heart failure, such as:

• Shortness of breath when you rest or do activities that did not cause problems before.
• Swelling of feet or legs.
• Sudden weight gain, such as 3 lb or more in 2 to 3 days.

Flecainide

Call your doctor right away if you have:

• Chest pain.
• Shortness of breath.
• Irregular heartbeat.
• Swelling in feet or legs.
• Trembling or shaking.

Procainamide

Call your doctor right away if you have:

• Fever and chills.
• Joint pain or swelling.

Propafenone

Call your doctor right away if you have:

• Chest pain.
• Shortness of breath.
• Changes in your heartbeat such as fast, slow, or irregular.
• Dizziness, lightheadedness, or fainting.
• Swelling in feet or legs.

Other side effects of propafenone may include a change in taste, such as metallic taste in your mouth.

Quinidine

Call your doctor right away if you have:

• Stomach pain.
• Yellow eyes or skin.
• Vision changes.
• Dizziness, lightheadedness, or fainting.
• Confusion.

Sotalol

Call your doctor right away if you have:

• Dizziness, lightheadedness, or fainting.
• Fast heartbeats.

Other side effects of sotalol may include a slow heart rate.

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

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