Betapace (Sotalol) - Oral


Betapace (sotalol) is an effective medication for abnormal heart rhythms; however, it has rare but serious life-threatening adverse effects. For example, Betapace can potentially cause an extremely rapid heart rate due to a prolonged QT interval or when your heart’s lower chambers take a long time to contract and relax. Your healthcare provider will determine if it is appropriate for you to take sotalol. To prevent these potentially severe adverse effects, speak to your healthcare provider when starting or restarting Betapace treatment about considering continuous electrocardiogram (ECG) monitoring at a clinic near you.

What Is Betapace?

Betapace (sotalol) is a prescription-only pill used to treat abnormal heart rhythms in the upper and lower chambers of the heart. It is an antiarrhythmic medication in a drug class known as beta-blockers.

Beta-blockers work by blocking beta receptors in the heart, which decreases your heart rate and makes it easier for the heart to pump blood to the rest of your body. In addition, sotalol can also block potassium channels located in the muscle of the heart. When a potassium channel is blocked, it extends the time it takes for another heartbeat to occur. This helps to regulate heart rhythm.

Sotalol is available as a tablet to be taken by mouth.

Drug Facts

Generic Name: Sotalol

Brand Name(s): Betapace, Betapace AF, Sorine, Sotylize

Drug Availability: Prescription

Therapeutic Classification: Antiarrhythmic agent

Available Generically: Yes

Controlled Substance: N/A

Administration Route: Oral

Active Ingredient: Sotalol hydrochloride

Dosage Form(s): Tablet

What Is Betapace Used For?

Betapace is used to regulate heart rhythm in people with abnormal heart rhythms in the upper or lower chambers of the heart.

An irregular heartbeat in the upper chamber is also known as atrial fibrillation. Betapace helps return the heart to its normal rhythm in people with atrial fibrillation symptoms. It is also used for life-threatening emergencies and as long-term treatment in ventricular fibrillation or an irregular heartbeat in the lower chambers.

How to Take Betapace

As with any medication, always take Betapace as instructed by your healthcare provider and follow their directions as stated.

Before you are prescribed Betapace, your healthcare provider should monitor your electrolyte levels and ECG. Typically, it is given as one 40-to-160 milligram tablet by mouth once every 12 hours. If the initial dose does not improve your condition, your healthcare provider may increase the dosage to a maximum of 160 milligrams twice daily.

The following are recommendations for how to take Betapace:

  • Take it with or without food, as long as you stick to one or the other.
  • When taking Betapace for the first time, take the first dose before bedtime because the medication can cause dizziness. If dizziness does not occur, the first dose can be taken in the morning.
  • Do not take antacids containing aluminum oxide or magnesium hydroxide (such as Tums or Rolaids) within two hours of taking Betapace. 

Your healthcare provider will monitor your electrolytes and ECG throughout your treatment.


Store the tablets at room temperature (between 68 F and 77 F) and away from moisture. Do not store it in the bathroom. Not storing the medication properly can affect how well it works.

As always, ensure your medication is stored in a safe place where children and pets cannot reach it to prevent accidental consumption. Contact your pharmacist or prescriber to request a refill if you need morel.

Off-Label Uses

While Betapace is commonly prescribed to treat abnormal heart rhythm, it has also been studied for the following uses:

  • Extra heartbeats in the lower chambers of the heart (premature ventricular contraction)
  • Prevention of atrial fibrillation after heart surgery
  • Rapid heart rate in a fetus

How Long Does Betapace Take to Work?

After taking the first dose, Betapace can take two to four hours to work. However, it may take up to two to three days to relieve symptoms and fully regulate your abnormal heart rhythm.

What Are the Side Effects of Betapace?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at or 1-800-FDA-1088.

Common Side Effects

The following side effects are commonly reported while taking Betapace:

  • Dizziness, weakness, or tiredness
  • Slow heart rate (bradycardia) or a new arrhythmia (proarrhythmia)
  • Upset stomach, diarrhea, or vomiting
  • Shortness of breath
  • Rash

Severe Side Effects

Call your healthcare provider immediately if you have serious side effects. Dial 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Rare but serious side effects and their symptoms can include the following:

  • Fainting (syncope)
  • Chest pain or pressure
  • Fast or slow heartbeat
  • Worsening abnormal heartbeat

Long-Term Side Effects

It is important to continue your treatment until your healthcare provider tells you it is OK to stop. If you suddenly stop taking Betapace after taking it for a while, you may experience a heart attack, chest pain, or an unusual heartbeat.

Your healthcare provider may need to gradually reduce your dosage and monitor for side effects.

Report Side Effects

Betapace may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Betapace Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For abnormal heart rhythms:
    • For oral dosage forms (solution or tablets):
      • Adults—At first, 80 milligrams (mg) once or 2 times a day. Your doctor may adjust your dose every 3 days as needed.
      • Children—Use and dose must be determined by your doctor.
    • For oral dosage forms (Betapace® and Betapace® AF tablets):
      • Adults—At first, 80 milligrams (mg) 2 times a day. Your doctor may adjust your dose every 3 days as needed.
      • Children 2 years of age and older—Dose is based on body weight and must be determined by your doctor. At first, the dose is usually 1.2 mg per kilogram (kg) of body weight 3 times a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 2.4 mg per kg of body weight 3 times a day.
      • Children younger than 2 years of age—Use and dose must be determined by your doctor.


Treatment or dosages of Betapace may need to be adjusted for any of the following:

  • Pregnancy: Sotalol can cause negative outcomes when used during pregnancy. However, so can the underlying health condition if left untreated. If you are pregnant or become pregnant while on this medication, talk to your healthcare provider about the best plan of action for ensuring the safety of you and the baby.
  • Children: Dosing is based on your child's height, weight, and age. The healthcare provider will let you know the correct dosage for your child.
  • Difficulty swallowing pills: If you or your child has difficulty swallowing pills, you can request a liquid solution form of sotalol.
  • Kidney problems: Since Betapace is mainly removed by the kidneys, advise your healthcare provider of any poor kidney function so they can provide the appropriate dosage for you.

Missed Dose

Skipping a dose on accident will not harm you. However, it is essential to take your doses as prescribed, so your treatment works effectively.

If you happen to miss a dose, skip the missed dose and resume back to when you regularly take Betapace. It is important to take only one tablet orally every 12 hours, so do not take two tablets simultaneously to make up for the missed dose. Taking more sotalol than instructed can lead to severe side effects.

Overdose: What Happens If I Take Too Much Betapace?

Typically, amounts that can lead to a significant overdose of sotalol range from 2 to 16 grams. However, even taking any amount greater than one tablet within 12 hours can put you at risk for severe side effects, such as:

  • Slow heart rate
  • Dizziness
  • Chest pain
  • Wheezing 
  • Shakiness 

An overdosage of this medication can lead to death. Therefore, it is crucial to only take as much as prescribed. If you take more, immediately seek medical help.

What Happens If I Overdose on Betapace?

If you think you or someone else may have overdosed on Betapace, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Betapace, call 911 immediately.


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It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood, urine, and ECG tests will be needed to check for unwanted effects.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

This medicine may make you dizzy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you. Stand up slowly if you feel dizzy or lightheaded.

Do not interrupt or stop taking this medicine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are taking before stopping it completely. Some conditions may become worse when the medicine is stopped suddenly, which can be dangerous.

Sotalol may cause heart failure in some patients. Check with your doctor right away if you are having chest pain or discomfort, dilated neck veins, extreme fatigue, irregular breathing, an irregular heartbeat, swelling of the face, fingers, feet, or lower legs, or weight gain.

This medicine may cause changes in your blood sugar levels. Also, this medicine may cover up signs of low blood sugar, such as a rapid pulse rate. Check with your doctor if you have these problems or if you notice a change in the results of your blood or urine sugar tests.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine. You may need to stop using this medicine several days before having surgery or medical tests.

This medicine may cause a serious type of allergic reaction called anaphylaxis, which can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Betapace?

You should not take sotalol if you are diagnosed with any of the conditions listed below without extensive discussion with your healthcare provider:

  • Severe, life-threatening allergy to any of the Betapace ingredients
  • Long QT syndrome
  • Poor kidney function
  • Asthma 
  • Slow heart rate
  • Heart attack in the past two weeks
  • History of heart failure
  • Diabetes
  • Low potassium levels

What Other Medications Interact With Betapace?

When taking Betapace, be aware of medications or supplements that may worsen side effects or lower the effectiveness of your treatment.

Betapace should not be taken with other antiarrhythmic medications or blood-pressure-lowering drugs. Since sotalol also lowers the heart rate and blood pressure, combining these medications can exacerbate those effects.

Common heart-related medications include:

Additionally, avoid taking antacids containing aluminum oxide or magnesium hydroxide within two hours of taking Betapace. This is because they can affect the rate at which sotalol reaches its target in the body, preventing it from being as effective.

Common antacids that contain aluminum oxide or magnesium hydroxide include:

  • Mylanta
  • Mygel
  • Gelusil
  • Rulox

What Medications Are Similar?

Medications similar to Betapace are available to help treat abnormal heart rhythms of the upper and lower heart chambers. These include:

  • Amiodarone
  • Tikosyn (dofetilide)
  • Flecainide


Both amiodarone and sotalol are equally effective in maintaining normal heart rhythm. However, the main difference between amiodarone and sotalol is the recurrence of abnormal heart rhythm after treatment and adverse effects. Amiodarone does a better job of preventing atrial fibrillation from happening again. However, it had more adverse effects than sotalol.


Both dofteilide and sotalol are sensitive to worsening heart effects, such as long QT syndrome. Although dofetilide is equally effective in treating abnormal heart rhythms, long QT syndrome was more common in people treated with dofetilide compared with sotalol.


There are no direct studies comparing sotalol with flecainide. Both can help an irregular heartbeat return to normal. However, flecainide cannot be used in people with ischemic heart disease (narrowed heart arteries), as it can worsen their heart rhythm. You can only use it if you have no history of heart disease.

This is a list of medications also used to treat irregular heart rhythms. It is not a list of medications recommended to take with Betapace. Contact your pharmacist or healthcare provider if you have questions. 

Frequently Asked Questions

  • Do I have to go to a clinic to monitor my ECG and electrolyte levels?

    Yes, Betapace can cause worsening heart problems in certain people. Monitoring your ECG and electrolytes can help make sure that sotalol is right for you. Ask your healthcare provider about this potential risk.

  • When should I go to the clinic to monitor my ECG and electrolytes levels?

    Before taking Betapace, your healthcare provider should order you a visit to a clinic for close monitoring. Most likely, they will monitor you for at least three days to make sure the appropriate dose given is safe and effective.

  • What if I have trouble swallowing pills? Is there another way to take sotalol?

    Yes, sotalol can also be prescribed as a liquid solution taken by mouth. If you or your child have difficulty swallowing pills, ask the prescribing healthcare provider whether the solution would be a better option for you.

  • How much does Betpace cost?

    The brand medication, Betapace, can be expensive. How much you spend out of pocket will depend on your health insurance status. The generic medication, sotalol, is available at a lower cost. If costs are a concern for you, ask your healthcare provider about the generic version.

How Can I Stay Healthy While Taking Betapace?

To stay healthy while on Betapace, you must take this medication exactly as instructed. Continue taking your doses even if you feel better unless your healthcare provider tells you to stop.

If you have been taking it for a while, stopping sotalol abruptly can lead to worsened heart problems or potentially a heart attack. Therefore, you should always consult your healthcare provider before stopping the medication. They may need to lower your dosage gradually.

Lifestyle changes can help you feel better faster. Consider engaging in light exercise and lowering your sodium intake. Ask your healthcare provider what other lifestyle choices you can make to improve your condition. It might be challenging to change your habits, but you can start small and gradually work your way up.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

The author would like to recognize and thank Alexya Rosas and Cody Ryan Thomas for contributing to this article.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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