Beta blockers are medicines 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.
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, Bisopine, Cardicor or Emcor)
- nebivolol (also called Nebilet, Nebimel, Nebol or Nelet)
- atenolol (also called Atecor, Atenomel, Tenormin or Trantalol)
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
- heart failure
Get emergency help
You might need emergency help if you take too much, have serious side effects or an allergic reaction.
If you take too much
You can overdose if you take too much of a beta blocker. This can be dangerous.
Emergency action required: Call 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.
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 999 or go to an emergency department (ED) if:
- you get a skin rash
- 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
When you start taking beta blockers
When you start on beta blockers, your doctor may ask you to take the first dose before bedtime because it can make you feel dizzy.
If you do not feel dizzy after the first dose, it’s best to take your medicine in the morning.
Beta blockers start to work after about 3 hours to reduce high blood pressure. But it can take up to 2 to 6 weeks to take full effect.
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 in the past
- 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 for your beta blocker dose.
It’s common to take beta blockers 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.
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
Take your missed dose as soon as you remember. But if it's nearly time for the next dose, skip the missed dose and take your next 1 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.
Side effects of beta blockers
Talk to your GP or pharmacist if side effects bother you or don't go away.
Side effects can include:
- feeling tired, weak or dizzy
- cold hands or feet
- feeling or being sick
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 the Health Products Regulatory Authority (HPRA): report an issue - hrpa.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)
- 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.
There's little information about taking herbal remedies and supplements with beta blockers. Tell your GP if you take any.
This content was fact checked by a pharmacist, a GP, the National Medication Safety Programme (Safermeds) and the Health Products Regulatory Authority (HPRA).