Medicine Information

  • Atrial fibrillation
  • Arrhythmia
  • Sotalol: forum
  • AF Association: charity
  • British Heart Foundation: charity

Sotalol belongs to a group of medicines called beta blockers.

It is used to treat atrial fibrillation and other conditions that cause an irregular heartbeat.

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

  • Sotalol slows down your heart rate and makes it easier for your heart to pump blood around your body.
  • Your very first dose of sotalol may make you feel dizzy, so take it at bedtime. After that, if you don’t feel dizzy, you can take it in the morning.
  • It’s usual to take sotalol either once a day, in the morning – or twice a day, in the morning and evening.
  • The main side effects of sotalol are feeling dizzy or sick, feeling tired, having diarrhoea or a headache – these are usually mild and short-lived. You’re more likely to have side effects if you’re on a very high dose of sotalol.
  • Sotalol is also known by the brand names Sotacor and Beta-Cardone.

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 isn’t suitable for everyone.

To make sure it is safe for you, tell your doctor before starting sotalol if you have:

  • had an allergic reaction to sotalol or any other medicine in the past
  • low blood pressure or a slow heart rate
  • heart failure which is getting worse, heart disease, or you’ve recently had a heart attack
  • any problems with your kidneys
  • an overactive thyroid (hyperthyroidism) – sotalol may make it more difficult to recognise the warning signs of having too much thyroid hormone in your body (thyrotoxicosis)
  • severe blood circulation problems in your limbs (such as Raynaud’s phenomenon), which may make your fingers and toes tingle or turn pale or blue
  • metabolic acidosis – when there is too much acid in your blood
  • a lung disease or severe asthma
  • severe diarrhoea

It’s usual to 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 don’t feel dizzy, you can take sotalol in the morning.

If you have 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.


The usual dose of sotalol is between 80mg and 320mg a day. If you experience 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.


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. Some brands have a score line to help you break the tablet to make it easier to swallow.

Check the information leaflet for your brand to see if you can do this.


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

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.


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.


If you go to a hospital accident and emergency (A&E) department, 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.

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.


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:

  • headaches
  • feeling tired, dizzy or weak
  • cold hands or feet
  • feeling or being sick (nausea or vomiting)
  • diarrhoea


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

Tell a doctor straight away if you have:

  • shortness of breath with a cough which gets worse when you exercise (like walking up stairs), swollen ankles or legs, chest pain, an irregular heartbeat – these are signs of heart problems
  • shortness of breath, wheezing and tightening of the chest – these can be signs of lung problems
  • palpitations, and tingling, numbness or cramping in your arms and legs – these are signs of low potassium or magnesium levels
  • feeling very thirsty and sweating a lot for no obvious reason – these can be signs of low or high blood sugar levels (hypoglycaemia or hyperglycaemia)

Serious allergic reaction

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


  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you’re wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

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

You can report any suspected side effect to the UK safety scheme.

What to do about:

  • headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Headaches usually go away after the first week of taking sotalol. Talk to your doctor if the headaches last longer than a week or are severe.
  • feeling tired, dizzy or weak – if sotalol makes you feel dizzy or weak, stop what you’re doing and sit or lie down until you feel better. Do not drive or use tools or machinery if you’re feeling tired. Do not drink alcohol as it will make you feel worse.
  • cold hands or feet – put your hands or feet under warm running water, massage them and wiggle your fingers and toes. Do not smoke or have drinks with caffeine in – these can make your blood vessels narrower and restrict your blood flow. Smoking also makes your skin colder. Try wearing mittens (they’re warmer than gloves) and warm socks. Do not wear tight watches or bracelets.
  • feeling or being sick (vomiting) – stick to simple meals and don’t eat rich or spicy food. It might help to take your sotalol after you’ve eaten. If you’re being sick, try small frequent sips of water.
  • diarrhoea – drink plenty of water or other fluids. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

Sotalol isn’t usually recommended in pregnancy or while breastfeeding.

If you’re trying to get pregnant or you’re already pregnant, talk to your doctor about the benefits and possible harms of taking sotalol.


Sotalol passes into breast milk and has been linked with side effects in breastfed babies.

Talk to your doctor, as there are other medicines that might be better while you’re breastfeeding.


  • trying to get pregnant
  • pregnant
  • breastfeeding

There are some medicines that may interfere with the way sotalol works.

Tell your doctor if you’re taking:

  • medicines that can cause abnormal heart rhythms – these include some antibiotics, like clarithromycin and erythromycin, and some antidepressants, like citalopram and amitripyline
  • other medicines used to treat an irregular heartbeat, such as amiodarone
  • medicines for high blood pressure, such as diltiazem and verapamil
  • medicines that can lower your potassium levels – these include medicines that make you pee, like furosemide, and some steroids, like prednisolone
  • medicines for asthma or chronic obstructive pulmonary disease (COPD)
  • medicines for allergies, such as ephedrine, noradrenaline or adrenaline


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


For safety, tell your doctor or pharmacist if you’re taking any other medicines, including herbal medicines, vitamins or supplements.

Sotalol is a type of medicine called a beta blocker.

Like other beta blockers, sotalol works by changing the way your body responds to some nerve impulses, especially in the heart. It slows down your heart rate and makes it easier for your heart to pump blood around your body.

Sotalol starts to work after about 4 hours, but it can take 2 to 3 days to fully take effect.

There’s no firm evidence to suggest that taking sotalol will reduce fertility in either men or women. If you’re trying for a baby, or you’re having problems getting pregnant while on sotalol, speak to your doctor.

Some people on sotalol say their sex drive goes down or they can’t get an erection. However, this isn’t a common side effect and there isn’t enough evidence to say for sure that sotalol is causing it.

If you’re having problems with your sex life, talk to your doctor.

You don’t need to stop playing sports if you take sotalol. But don’t push yourself too much.

Regular exercise is good for you because it lowers blood pressure by keeping your heart and blood vessels in good condition. Be aware, though, that in some sports sotalol is not allowed if you’re competing at a high level.

Sotalol can make some people feel dizzy – especially when you first start taking it or after taking a bigger dose. If this happens to you, do not drive a car, ride a bike, or use tools or machinery.

  • Quit smoking – smoking increases your heart rate and blood pressure. Quitting smoking brings down your blood pressure and relieves heart failure symptoms. Try to avoid secondhand smoke.
  • Cut down on alcohol – drinking too much alcohol raises blood pressure over time. It makes heart failure worse too. Try to keep to the recommended guidelines of no more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units. A pint of lager or beer is usually 2 to 3 units of alcohol.
  • Exercise – regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition. It doesn’t need to be too energetic – walking every day will help.
  • Eat well – aim to eat a diet that includes plenty of fruit and veg, wholegrains, fat-free or low-fat dairy products and lean proteins. It’s a good idea to cut down on salt too. Eating too much salt is the biggest cause of high blood pressure – the more salt you eat, the higher your blood pressure will be. Aim for no more than 6g of salt a day.
  • Deal with stress – when you’re anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up. This can make heart failure worse too. Find ways to reduce stress in your life. To give your heart a rest, try napping or putting your feet up when possible. Spend time with friends and family to be social and help avoid stress.

Usually, treatment with sotalol is long term, even for the rest of your life.

Sotalol is generally safe to take for a long time. In fact, it works best when you take it for a long time.

Talk to your doctor if you want to stop taking sotalol.

Stopping sotalol suddenly can make your condition worse.

If you’re bothered by side effects, your doctor may be able to prescribe a different medicine for your heart problems.

If you stop taking sotalol, it will take about 4 days for it to be completely out of your body.

Sotalol is not considered as a typical beta blocker. This is because it is not generally used to treat high blood pressure and is mainly used for irregular heartbeats. Sotalol is classed as a potassium blocker.

There are 4 main types of medicines for treating irregular heartbeats:

  • sodium channel blockers – for example flecainide
  • beta blockers – for example propranolol and atenolol
  • potassium blockers – for example sotalol and amiodarone
  • calcium channel blockers – for example verapamil

They all work a little bit differently to help regulate your heartbeat – and the side effects can also be different. Sometimes you may have to try other medicines for an irregular heartbeat if you get side effects.

Tell your doctor that you’re taking sotalol if you’re going to be put to sleep (using general anaesthetic), or you’re having any kind of major operation.

Your doctor may advise you to stop taking sotalol before surgery. This is because sotalol can lower your blood pressure too much when it’s combined with some anaesthetics.

Drinking alcohol can increase the risk of side effects with sotalol. It can make you feel dizzy or lightheaded.

During the first few days of taking sotalol or after an increase in your dose, it’s best to stop drinking alcohol until you see how the medicine affects you.

If you find sotalol makes you feel dizzy it’s best to stop drinking alcohol.

You can eat and drink normally while taking sotalol.

Eating a healthy, balanced diet can help if you have a heart condition.

Sotalol won’t stop your contraception working.

However, some types of hormonal methods of contraception, like the combined pill and contraceptive patch, aren’t usually recommended for women with heart problems. Talk to your doctor if you’re taking a combined hormonal contraceptive.