About sotalol

Sotalol belongs to a group of medicines called beta blockers.

It's used to treat atrial fibrillation and other conditions that cause an irregular heartbeat (arrhythmia).

This medicine is only available on prescription. It comes as tablets.

Key facts

Who can and cannot take sotalol

Sotalol can be taken by adults and children over the age of 12 years. It can also be taken by children under the age of 12 on the advice of their specialist.

It is not suitable for everyone.

To make sure it's safe for you, tell your doctor before starting to take sotalol if you have:

How and when to take sotalol

Take sotalol exactly as your doctor has told you, and follow the instructions on the label. If you're not sure, check with your doctor or pharmacist.

You'll usually take sotalol once or twice a day.

Your doctor may advise you to take your first dose before bedtime, because it can make you feel dizzy. After the first dose, if you do not feel dizzy, you can take sotalol in the morning.

If you take sotalol twice a day, try to take it in the morning and in the evening.


Take sotalol even if you feel well, as you will still be getting the benefits of the medicine.


Sotalol tablets come in different strengths: 40mg, 80mg and 160mg.

The usual dose of sotalol is between 80mg and 320mg a day. If you get irregular heartbeats several times a day, your doctor may prescribe a higher daily dose of up to 640mg.

If you are older or have kidney problems, your doctor may give you a lower dose.

How to take it

You can take sotalol with or without food, but it's best to do the same each day.

Swallow the tablets whole with a drink of water.

If you forget to take it

If you miss a dose of sotalol, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose at the usual time.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

If you take too much

Taking too much sotalol can slow down your heart rate and make it difficult to breathe. It can also cause dizziness and trembling.

The amount of sotalol that can lead to an overdose varies from person to person.

Contact 111 for advice now if:

  • you take more than your prescribed dose of sotalol

Go to or call 111

If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.

Take the sotalol packet, or the leaflet inside the packet, plus any remaining medicine with you.

Go to A&E now if:

You take more than your prescribed dose of sotalol and:

  • your heart rate (pulse) has slowed down
  • you are having difficulty breathing

Find your nearest A&E.

Side effects

Like all medicines, sotalol can cause side effects in some people, but many people have no side effects or only minor ones. Side effects often improve as your body gets used to the medicine.

Common side effects

These common side effects happen in more than 1 in 100 people. They're usually mild and short-lived.

Talk to your doctor or pharmacist if the side effects bother you or last more than a few days:

Serious side effects

It happens rarely, but some people have serious side effects when taking sotalol.

Call 111 or call your doctor now if:

Call 999 or go to A&E if:

  • you have shortness of breath with a cough which gets worse when you exercise (like walking upstairs), swollen ankles or legs, chest pain, or an irregular heartbeat – these are signs of heart problems
  • you have shortness of breath, wheezing and tightening of your chest – these can be signs of lung problems

Serious allergic reaction

In rare cases, sotalol may cause a serious allergic reaction (anaphylaxis).

These are not all the side effects of sotalol. For a full list, see the leaflet inside your medicine packet.

How to cope with side effects of sotalol

What to do about:

Pregnancy and breastfeeding

Sotalol and pregnancy

Sotalol can be used in pregnancy, particularly if you have problems with your heart.

However, always check with your doctor that they are happy for you to keep taking it. They may wish to review your medicine and may recommend other medicines instead.

If you do take sotalol in pregnancy then you may need extra scans to check that your baby is growing at a normal rate.

Sotalol and breastfeeding

If your doctor or health visitor says that your baby is healthy, it's OK to take sotalol while you're breastfeeding.

Sotalol can pass into breast milk in quite high amounts, but studies looking at sotalol have not shown any side effects in breastfed babies. Other beta blockers have been linked with side effects in breastfed babies.

It's important to keep taking sotalol to keep you well. Breastfeeding will also benefit both you and your baby.

If you notice that your baby is not feeding as well as usual, or seems unusually sleepy, seems much paler than usual, or if you have any other concerns about your baby, talk to your health visitor, midwife or doctor as soon as possible. They may recommend a different medicine for you to take.

For more information about how sotalol can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.

Cautions with other medicines

There are some medicines that may affect the way sotalol works.

Tell your doctor if you're taking:

Mixing sotalol with herbal remedies or supplements

There's very little information about taking herbal remedies and supplements with sotalol.

Common questions about sotalol

How does sotalol work? How long does sotalol take to work? How long will I take it for? Is it safe to take for a long time? What will happen if I stop taking it? Do I need to have regular blood tests if I'm taking sotalol? How does it compare with other heart medicines? Will I need to stop sotalol before surgery? Can I drink alcohol with it? Is there any food or drink I need to avoid? Will it affect my contraception? Will it affect my fertility? Will it affect my sex life? Do I need to avoid playing sports? Can I drive or ride a bike? Can lifestyle changes help my heart?