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Boxed warning

Sotalol has a boxed warning for life-threatening proarrhythmia. You will need to start or restart sotalol treatment in a healthcare facility where you can undergo continuous electrocardiographic monitoring and cardiac resuscitation if needed.

What is sotalol?

Sotalol (Betapace) and sotalol AF (Betapace AF) are non-cardioselective beta-blocker medications that fall under the classification of antiarrhythmic drugs.¹

The drug is used to treat arrhythmia (irregular heartbeat). It works on the heart muscles to regulate and slow the heart rate.²

You can only access sotalol with a doctor’s prescription.

Warnings and precautions

Sotalol has a boxed warning for causing life-threatening arrhythmias.³

When you first start taking sotalol or start taking it again after a period of discontinuation, you will need to be placed in a healthcare facility for at least three days where you can be resuscitated if needed and continuously monitored via electrocardiography.

Sotalol and sotalol AF should not be used interchangeably. Each medication is indicated for a different condition and should not substitute each other due to significant differences in safety information, dose administration, and labeling.

Sotalol is contraindicated for people with:

  • Bronchial asthma

  • Sinus bradycardia

  • Baseline QT interval > 450 msec

  • Congenital or acquired long QT syndromes

  • Cardiogenic shock

  • Uncontrolled heart failure

  • Creatinine clearance < 40mL/min

  • Hypokalemia (< 4meq/L)

  • Hypersensitivity to sotalol

If you have any of these conditions, using sotalol could have fatal effects.

What does sotalol treat?

Sotalol is approved to treat life-threatening ventricular arrhythmias (like ventricular tachycardia).

Sotalol AF is approved for the maintenance of normal sinus rhythm in patients with symptomatic atrial fibrillation or flutter (AFIB/AFL).

The US Food and Drug Administration advises against using sotalol to treat people with less severe arrhythmias (even with symptoms) and people with asymptomatic premature ventricular contractions (PVCs).

The drug also shouldn’t be used by people with paroxysmal atrial fibrillation (intermittent episodes of atrial fibrillation that spontaneously stop within seven days or stop with other interventions).³

Dosage forms and strengths

Sotalol hydrochloride and sotalol hydrochloride AF are available as generic medications in the following dosage forms and strengths:

  • Sotalol hydrochloride (tablet for oral use): (80mg, 120mg, 160mg, and 240mg)

  • Sotalol hydrochloride AF (tablet for oral use): (80mg, 120mg, and 160mg)

  • Sotalol hydrochloride intravenous (IV) injection (15mg/mL)

The drug is also sold under several brand names, including:

  • Betapace/Betapace AF (tablet for oral use) (80mg, 120mg, and 160mg)⁴

  • Sorine (tablet for oral use) (80mg, 120mg, 160mg, and 240mg)⁵

  • Sotylize (solution for oral use) (5mg/mL in 250mL or 480mL bottles)⁶

How do you take sotalol?

You will need to stay in a hospital for three days when starting sotalol treatment or until your drug levels stabilize. This is because you will require close monitoring.

If you were already taking another medication for arrhythmia before starting sotalol, you will need to discontinue these medications. Follow your doctor’s advice on how to do so.

Sotalol/sotalol AF oral tablets are taken by mouth. Swallow the tablet whole with a glass of water. Do not chew or crush the tablets.

Sotalol injection is given intravenously. This will often be done by a healthcare practitioner.

Sotalol solution is taken by mouth and should be measured very carefully using the dosing syringe provided and not a tablespoon.

Do not take less or more than prescribed by your doctor.

You can take sotalol medication with or without food.

Do not stop taking sotalol without consulting your doctor.


The following are only general recommendations. Your doctor will be the one to recommend the most appropriate dosage and schedule depending on your condition and response to treatment. They will adjust your dose accordingly.

The usual adult dose for ventricular arrhythmias is 80mg twice daily. This may be increased gradually. You may eventually take 160–320mg per day in 2–3 divided doses, although higher doses may be needed in cases where life-threatening ventricular arrhythmias are resistant and life-threatening.

The usual adult dose to prolong the time before the recurrence of atrial fibrillation or flutter is 80mg twice daily. This may be gradually increased to 120mg twice daily.

Pediatric doses are based on the child’s age, height, and weight. Their doctor will change their dose while their bodies are still growing, and potentially if they gain or lose weight.³

Seeing results

After taking your first oral dose, sotalol begins to work in about four hours. However, it could take 2–3 days to have full effect.⁷

Who should not take sotalol

Sotalol is not suitable for you if:

  • You have had a previous allergic reaction to sotalol

  • You have heart conditions, including:

    • Slow heart rate (fewer than 50 beats per minute)

    • Heart failure

    • Long QT syndromes

    • Sick sinus syndrome

    • Second and third-degree AV block (unless you have a pacemaker fitted)

  • You have asthma or another lung condition

  • You have electrolyte disturbance, such as low potassium or magnesium levels. Imbalances need to be treated before you can start taking sotalol safely.

  • You have kidney failure (sotalol should not be taken by people with creatine clearance of less than 40mL/min)

  • You are taking other antiarrhythmic drugs, particularly class Ia antiarrhythmic drugs, such as disopyramide, quinidine, and procainamide, and other class III drugs (e.g., amiodarone)

Sotalol can be administered with extreme caution if:

  • You have low blood pressure

  • You have diabetes, particularly if you have a history of spontaneous low blood sugar episodes

  • You have hyperthyroidism (overactive thyroid)

  • You are taking any medications that interact with sotalol (see “Drug interactions” section below)

Potential side effects of sotalol

Like most drugs, sotalol causes side effects that range from mild to serious.

Common side effects of sotalol include:⁸

  • Fatigue

  • Asthenia (general weakness with physical and mental fatigue)

  • Dizziness

  • Chest pain

  • Fast heart rhythm

  • Palpitations

  • Low blood pressure

  • Headaches

  • Feeling lightheaded

  • Sleep problems

  • Slow heart rate

  • Worsening arrhythmia

  • Shortness of breath

  • Nausea

  • Vomiting

  • Diarrhea

  • Indigestion

  • Respiratory problems

  • Muscle pain

What to do if you experience side effects

Contact your doctor if you notice the following side effects don’t go away on their own or worsen:

  • Dizziness

  • Fatigue

  • Muscle aches

  • Headache

  • Lightheadedness

  • Constipation

  • Diarrhea

  • Upset stomach

Contact 911 immediately if you experience any of the following effects:

  • Chest pain

  • Shortness of breath

  • Difficulty breathing

  • Sudden or severe dizziness

  • Slow heart rate

  • Severe headache

  • Feeling your heart is beating too fast or too slow

  • Feeling your heart is pounding in your chest or skipping a beat

  • Wheezing

  • Swollen feet or lower legs

This is not an exhaustive list. You are advised to get in touch with your doctor if you experience any other side effects.


An overdose of sotalol is dangerous and can even be fatal.

Some signs of sotalol overdose include a slow or sometimes fast heart rate, heart failure (may cause shortness of breath, weakness, persistent cough or wheezing, swelling, fatigue, or fainting), low blood sugar, low blood pressure, and breathing problems.³

If you suspect you or someone you know has overdosed on sotalol, seek immediate emergency medical help.

Allergy information

Sotalol can cause an allergic reaction in some people. Some mild to severe symptoms that you might experience are:

  • Trouble breathing

  • Hives

  • Swelling of your lips, tongue, throat, or face

If you notice any of these symptoms of an allergic reaction, seek immediate medical attention or call 911.

Long-term use of sotalol

When taken as directed by your doctor, sotalol can be used safely over a long time. Sotalol works well when taken over an extended period.⁷

Stopping sotalol

It is dangerous to stop taking sotalol suddenly. Abruptly stopping this drug can worsen your condition or have fatal effects.

If you experience prolonged side effects while taking sotalol and want to stop the medication, talk to your doctor about changing to a different drug. Your doctor will tell you how to stop taking sotalol safely.

Pregnancy category

Sotalol is a pregnancy category B drug. This means no risk has been shown in animal studies, but there are no adequate studies in humans to confirm it is safe to use in pregnant women.⁹

Sotalol and pregnancy

Studies of sotalol use in pregnant animals have not shown a risk to the fetus (or have done so only at levels greater than human doses or at toxic levels).

There are not enough studies on sotalol in pregnant women to indicate the drug can harm a fetus. However, it has been reported that sotalol can cross the placenta, and it has been found in the amniotic fluid.

Before starting sotalol, inform your doctor if you are pregnant or plan to conceive. Sotalol should only be used during pregnancy if your doctor has decided that its benefits outweigh the potential risks.

Sotalol and breastfeeding

Sotalol can pass into breast milk. Your doctor may advise that either you can’t take sotalol while breastfeeding or you should stop breastfeeding and continue taking the drug. The decision should be taken based on the importance of this medication to your health.

Missed doses

If you miss a dose, take it as soon as you remember. If your missed dose is close to the time of your next dose, skip it entirely and take your next dose as usual.

Do not double your sotalol dose to catch up. This could lead to overdose and serious adverse effects.

If you miss more than one dose, contact your doctor.

Drug interactions

Sotalol interacts with some drugs and can cause harmful effects. These include the following:⁹ ⁷

  • Other antiarrhythmic drugs, including quinidine, disopyramide (Norpace), and amiodarone (Pacerone and Cordarone)

    • Some antibiotics (like erythromycin and clarithromycin ) and antidepressants (like citalopram and amitriptyline) also have antiarrhythmic effects and are contraindicated for people taking sotalol

  • Digoxin (Cardoxin, Lanoxicaps, Lanoxin, and Digitek)

  • Calcium-channel blockers, like verapamil (Calan, Verelan, and Covera HS) and diltiazem (Cardizem, Tiazac, and others)

  • Catecholamine-depleting drugs, such as reserpine, deserpidine, and guanethidine (these drugs may no longer be available where you live)

  • Insulin and oral antidiabetic drugs like metformin

  • Clonidine (Catapres and Kapvay)

  • Antacids that contain aluminum or magnesium, like Maalox and Mylanta (do not take sotalol within two hours of taking these drugs)

This is not an exhaustive list of all the potential drug interactions. You must inform your doctor of any other medications you are taking prior to using sotalol.

Can I drink alcohol while taking sotalol?

Drinking alcohol while taking sotalol can cause you to feel lightheaded and dizzy. Don’t drink alcohol at the start of treatment or shortly after your dose is increased. Instead, wait to see how the medication affects you.

If you find sotalol makes you feel dizzy, it’s best to avoid alcohol as it could worsen this effect.⁷

What to discuss with your doctor before starting sotalol

Before starting sotalol, tell your doctor about your current and past medical history, including the following:

Drug allergies: Let your doctor know about any drug allergies you have, including any previous allergic reaction to sotalol.

Medications: Provide your doctor with a complete list of prescription/non-prescription medicines you take, including herbal remedies and vitamins. Be sure to mention medications you take for colds, asthma, stomach acid, allergies, diabetes, migraines, heart disease, high blood pressure, and pain.

Medical conditions: Inform your doctor of your full medical history, including any current or previous health conditions, a family history of heart disease, and particularly if you have or ever had kidney disease, vascular disease, allergies, asthma (or any other lung condition), diabetes, or hyperthyroidism.²

Pregnancy/breastfeeding: Let your doctor know if you are pregnant, planning a pregnancy, or breastfeeding.

Drug approval history

1992: The FDA first approved sotalol to be sold under the brand name Betapace.

2000: The FDA approved sotalol AF for atrial fibrillation and atrial flutter to be sold as Betapace AF.¹⁰

2009: Sotalol hydrochloride as an IV injection was approved by the FDA for use in people who cannot take the medication orally.¹¹

2014: The FDA approved Sotylize oral solution.¹²

Tips and advice for taking sotalol

The following tips can help you take sotalol safely and effectively:

  • Always take sotalol as prescribed by your doctor.

  • Set your alarm as a reminder to take your medication on time.

  • Do not stop taking sotalol abruptly or without consulting your doctor

  • Inform your doctor about your complete medical history so that they can change your medication if necessary.

  • Never share your prescription with anyone else.

  • Avoid alcohol when taking this drug as it can make you feel drowsy.

Frequently asked questions

What does sotalol do for the heart?

Sotalol affects the heart muscles to regulate and slow your heart rate. This is why it’s used to treat arrhythmia (irregular heartbeat) and atrial fibrillation or flutter.

What are the side effects of sotalol?

The most common side effects of sotalol include fatigue, difficulty breathing, slow heart rate, and dizziness.

Does sotalol affect sleep?

Sotalol can cause difficulty sleeping. Speak to your doctor if this troubles you or doesn’t ease after you have been taking the medication for some time.

Curious about clinical trials?

Access the latest treatments and medications. unavailable elsewhere - entirely free of charge. We make it easy to take part.


Here at HealthMatch, we’ve done our best to ensure that the information provided in this article is helpful, up to date, and, most importantly, accurate.

However, we can’t replace the one-to-one advice of a qualified medical practitioner or outline all of the possible risks associated with this particular drug and your circumstances.

It is therefore important for you to note that the information contained in this article does not constitute professional medical or healthcare advice, diagnosis or recommendation of treatment and is not intended to, nor should be used to, replace professional medical advice. This article may not always be up to date and is not exhaustive of all of the risks and considerations relevant to this particular drug. In no circumstances should this article be relied upon without independent consideration and confirmation by a qualified medical practitioner.

Your doctor will be able to explain all possible uses, dosages, precautions, interactions with other drugs, and other potential adverse effects, and you should always talk to them about any kind of medication you are taking, thinking about taking or wanting to stop taking.

Curious about clinical trials?

Access the latest treatments and medications. unavailable elsewhere - entirely free of charge. We make it easy to take part.