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Heart Rate and Rhythm Controlling Medicines

Drugs that control heart rate or rhythm are called antiarrhythmics. They can prevent or treat a fast or irregular heart rate (arrhythmia). These drugs block fast or irregular electrical signals. This can improve symptoms and reduce the risk of serious health problems.1,2

Antiarrhythmic drugs are usually taken long-term. Many of these drugs also reduce blood pressure. Talk to your doctor about the risks and benefits. They can suggest the right medicines to control heart rate or rhythm.1

When are medicines used to control heart rate or rhythm?

Your doctor will suggest treatment depending on your type of arrhythmia. They may recommend starting with lifestyle changes. Your best treatment option depends on things like the severity of your arrhythmia and other health conditions you have.1

Your doctor may recommend medicines if you have other health conditions or risk factors. They also may suggest medicines if your arrhythmia:1,3

  • Does not respond to lifestyle changes
  • Interferes with daily activities
  • May cause a life-threatening problem, such as cardiac arrest

How do antiarrhythmic drugs work?

Antiarrhythmic drugs act on the heart’s electrical systems. The contraction of heart muscles follows cycles of electrical impulses. These impulses are caused by the movement of ions (electrically charged atoms). The ions move at a structure in the heart called the sinus node. The sinus node contains cells known as “pacemaker cells.”4

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Normally, these pacemaker cells trigger 60 to 100 impulses every minute. This leads to a resting heart rate of 60 to 100 beats per minute. In people with arrhythmia, these cells may cause fast or irregular impulses. Blocking sinus node signals or ion movement through channels can:1,2,4

  • Stop an irregular or extra electrical impulse in your heart
  • Prevent fast electrical impulses from traveling along heart tissues

A common strategy is to first use medicines that control heart rate. This includes beta blockers, calcium channel blockers, and digoxin. If symptoms continue or you have risk factors, your doctor may suggest medicines to control heart rhythm. These include sodium and potassium channel blockers.3,5,6

Types of antiarrhythmic medicines

Medicines that control heart rate and rhythm are defined by how they work. The main classes are:4

Sodium channel blockers

These drugs prevent sodium ions from going in and out of cells. This can slow the heart’s electrical impulses and help correct the heart’s rhythm. Examples of sodium channel blockers include:1,3

  • Disopyramide (Rythmodan®)
  • Flecainide (Tambocor®)
  • Mexiletine (Mexitil®)
  • Propafenone (Rythmol®)
  • Quinidine

Beta blockers

Beta blockers reduce the activity of hormones like adrenaline. They do this by interfering with how adrenaline binds to “beta receptors.” This slows pacemaker cell impulses and heart rate. Examples of beta blockers include:1-3

  • Acebutolol (Sectral®)
  • Atenolol (Tenormin®)
  • Bisoprolol (Zebeta®)
  • Metoprolol (Lopressor®)
  • Nadolol (Corgard®)
  • Propranolol (Inderal®)
  • Esmolol (Brevibloc®)

Potassium channel blockers

These drugs prevent potassium ions from going in and out of cells. This can slow the heart’s electrical impulses and help correct the heart’s rhythm. Examples of potassium channel blockers include:1,3

  • Amiodarone (Cordarone®, Pacerone®)
  • Bretylium tosylate (Bretylium®)
  • Dofetilide (Tikosyn®)
  • Dronedarone (Multaq®)
  • Ibutilide (Corvert®)
  • Sotalol (Betapace®)

Calcium channel blockers

These drugs block calcium channels in heart muscles. This can reduce heart rate and contractions. Examples of calcium channel blockers include:1-3

  • Diltiazem (Cardizem®)
  • Verapamil (Isoptin®)

Other examples

Adenosine (Adenocard®) and digoxin (Digitek®) slow heart rate. They block electrical impulses at the atrioventricular node. This structure connects the electrical systems of the atria and ventricles.1,3

What are side effects of antiarrhythmics?

The risk of side effects depends on the specific drug. They all have distinct side effect risks that must be monitored. Antiarrhythmic drugs can lead to other types of arrhythmias. For example, sodium channel blockers can increase the risk of ventricular tachycardia.2,4

Common side effects of antiarrhythmics include:1,4

  • Constipation
  • Dizziness or nausea
  • Skin changes
  • Headache
  • Ringing in the ears (tinnitus)
  • Vision changes
  • Swelling (edema),excessive thirst, or trouble urinating

These are not all the possible side effects. Talk to your doctor about what to expect when taking antiarrhythmics. You should also call your doctor if you have any changes that concern you.

What other drugs are used for arrhythmias?

People with arrhythmia often have other heart, lung, or thyroid conditions. Treatment may involve medicine for these conditions. People with atrial fibrillation often also take blood thinner medicines. This can reduce the risk of blood clots and stroke. Blood thinners include:2,3,7,8

  • Anticoagulants (such as warfarin) prevent new clots from forming or existing clots from growing.
  • Antiplatelets (such as aspirin) stop platelets from sticking together to form a blood clot.

Blood thinners can increase your risk of bleeding. Talk to your doctor about the risks and benefits of blood thinners.3

Treatment results and side effects can vary from person to person. This treatment information is not meant to replace professional medical advice. Talk to your doctor about what to expect before starting and while taking any treatment.

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