Beta blockers are medicines that are mainly used to treat heart problems and high blood pressure.
They work by slowing down the heart. They do this by blocking the action of hormones such as adrenaline.
Some beta blockers are also used for other conditions, including tremors, thyroid problems, anxiety and glaucoma.
Beta blockers are prescription-only and usually come as tablets.
Types of beta blockers
There are several types of beta blocker. The type prescribed for you will depend on your health condition.
Common beta blockers include:
- bisoprolol (also called Bisocor, Bisop, or Cardicor)
- nebivolol (also called Nebilet, Nebimel or Nebol)
- atenolol (also called Atecor or Atenomel)
- carvedilol (also called Eucardic)
- metoprolol (also called Metocor)
- propranolol (also called Beta Prograne)
- sotalol (also called Sotoger)
Uses of beta blockers
Beta blockers are used to treat:
- high blood pressure - when other medicines have been tried, or in addition to other medicines
- atrial fibrillation (irregular heartbeat)
- heart attack
- angina
- heart failure
Less commonly, beta blockers are used to prevent migraine or treat:
- tremors
- anxiety
- symptoms of too much thyroid hormone in your body (thyrotoxicosis)
- glaucoma - as eye drops
Some beta blockers are combined with other medicines. You can take a beta blocker with other medicines to treat your symptoms.
When you start taking beta blockers
When you start on beta blockers, your doctor may ask you to take the first dose before bedtime. This is because it can make you feel dizzy.
If you were not dizzy after your first dose, you'll usually take your medicine in the morning. This is if you take a beta blocker once a day.
Beta blockers start to work after about 3 hours. But it can take up to 2 to 6 weeks to work fully.
Keep taking beta blockers even if you feel well. You’ll still be getting the benefits of the medicine.
Check if you can take beta blockers
Beta blockers are not suitable for everyone.
To make sure it's safe tell your doctor if you:
- have had an allergic reaction to beta blockers or any other medicine
- have any other medical condition - including low blood pressure, circulation problems, metabolic acidosis, lung disease, or asthma
- get allergic reactions to things such as bee stings
- are pregnant, trying for a baby or breastfeeding
How and when to take it
Always follow the instructions on the medicines label on how and when to take it.
If you take a beta blocker once a day, it’s common to take it in the morning.
Beta blockers do not usually upset your stomach, so you can take it with or without food. It's best to take it the same way each day.
Swallow tablets whole with a drink of water. If you find them difficult to swallow, ask your pharmacist if you can cut them in half.
Stopping taking beta blockers
It’s important not to stop taking beta blockers without asking your GP. Stopping suddenly may make your health condition worse.
If they work well for you, beta blockers are generally safe to take for a long time. You may need to take them for the rest of your life.
Food and alcohol
You can eat normally while taking beta blockers.
Drinking alcohol can increase the blood pressure-lowering effect of beta blockers. If this makes you feel dizzy, it's best to stop drinking alcohol.
During the first few days of taking a beta blocker or after an increase in your dose, it's best to stop drinking alcohol.
If you forget to take a dose
If you forget to take a dose of your beta blocker, take it as soon as you remember. But if it's nearly time for your next dose, skip the missed dose and take your next dose as normal.
Do not take a double dose to make up for a forgotten dose.
If you often forget doses, it may help to set a reminder alarm.
If you take too much
It can be dangerous to take too much of a beta blocker.
Emergency action required: Call 112 or 999 or go to an emergency department (ED) if you have:
- breathing difficulties
- a very slow heart rate
- dizziness or trembling
Dizziness and breathing difficulties can be signs of a very slow heart rate.
Side effects of beta blockers
Most people taking beta blockers have no side effects or very mild side effects. These usually ease over time.
Talk to your GP or pharmacist if side effects bother you or do not go away.
Common side effects are things you can do to help cope with common side effects:
Feeling tired, weak or dizzy
If you feel dizzy or weak, stop what you're doing. Sit or lie down until you feel better. Do not drive, cycle or use tools or machinery. 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, such as coffee, tea and cola. 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
Stick to simple meals if you feel sick (nausea) or you have been getting sick (vomiting).
Do not eat rich or spicy food. It might help to take your beta blocker after you have eaten.
Try drinking small, frequent sips of water. Contact a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee.
Do not take medicines to treat vomiting without speaking to a pharmacist or GP. If you take the combined contraceptive pill or progestogen-only pill and you're getting sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Diarrhoea
Drink lots of fluids to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
If you take contraceptive pills and have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Do not take any medicines to treat diarrhoea without speaking to a pharmacist or GP.
Constipation
Get more fibre into your diet, such as fresh fruit, vegetables and cereals. Drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk or run. If this does not help, talk to your pharmacist or GP.
Headaches
Rest and drink plenty of fluids. It's best not to drink too much alcohol. Ask a pharmacist to recommend a painkiller. Headaches usually go away after the first week of taking a beta blocker. Talk to your GP if the headaches are severe or last longer than a week.
Contact a GP or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or lasts more than a few days.
Serious side effects
Beta blockers can cause serious side effects.
Emergency action required: Go to your nearest ED or phone your GP immediately if you have:
- shortness of breath
- a cough that gets worse with exercise
- swollen ankles or legs
- chest pain or irregular heartbeat
- shortness of breath, wheezing or a tight chest
- yellow skin or eyes
- a high temperature, trembling or confusion
Serious allergic reaction
A serious allergic reaction (anaphylaxis) to beta blockers is rare.
Emergency action required: Call 112 or 999 or go to an ED if:
- you get a skin rash
- you're wheezing
- you get tightness in your chest or throat
- you have trouble breathing or talking
- your mouth, face, lips, tongue or throat start swelling
Read the patient information leaflet that comes with your medicine for a full list of side effects.
Non-urgent advice: Find your patient information leaflet
Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.
Report side effects
You can report any suspected side effects to the Health Products Regulatory Authority (HPRA): report an issue - hpra.ie
Taking beta blockers with other medicines
Some medicines may interfere with beta blockers.
Tell a GP or pharmacist if you're taking other medicines.
This includes medicines for:
- high blood pressure or heart problems
- asthma or chronic obstructive pulmonary disease (COPD)
- allergies
- diabetes - beta blockers may make it more difficult to recognise the warning signs of low blood sugar
- colds or sinus congestion
- blood pressure
Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can also stop beta blockers from working as well as they should. They may also increase your blood pressure.
Herbal remedies and supplements
There's little information about taking herbal remedies and supplements with beta blockers. But tell your GP if you take any supplements. This is important.
Fact check
This content was fact checked by a pharmacist, a GP, and the National Medication Safety Programme (Safermeds).
