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.

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:

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

Serious side effects

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).

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 and breastfeeding

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.

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

Mixing sotalol with herbal remedies or supplements

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

How does sotalol work?