- Labetalol slows down your heart rate and makes it easier for your heart to pump blood around your body.
- It's usual to take labetalol twice a day. Some people take it 3 or 4 times a day.
- The main side effects of labetalol are feeling dizzy or weak, itchy skin, a rash or tingly scalp, and difficulty peeing. These usually happen at the start of treatment and are short-lived.
- If you're pregnant, labetalol is the first choice of medicine for treating high blood pressure.
- Do not stop taking labetalol suddenly, especially if you have heart disease. This can make your condition worse.
- Labetalol is also known by the brand name Trandate.
Labetalol can be taken by adults. It can sometimes be prescribed for babies and children by a specialist.
It's not suitable for everyone. To make sure it's safe for you, tell your doctor before starting labetalol if you:
- have had an allergic reaction to labetalol or any other medicine in the past
- have liver or kidney problems
- have low blood pressure or a slow heart rate
- have heart failure that's getting worse, heart disease, or you have recently had a heart attack
- have severe blood circulation problems in your arms and legs (such as Raynaud's), which may make your fingers and toes tingle or turn pale or blue
- have a lung disease or asthma
Adults and children aged 11 years and over usually take labetalol twice a day.
If you're on a high dose, you may need to take it 3 or 4 times a day.
Younger children usually take labetalol 3 or 4 times a day.
Try to space your doses out evenly throughout the day.
Take labetalol even if you feel well, as you'll still be getting the benefits of the medicine.
Do not stop taking labetalol suddenly, especially if you have heart disease. This can make your condition worse.
If you want to stop taking your medicine, speak to your doctor. They may recommended reducing your dose gradually over a few weeks.
How much will I take?
The usual dose of labetalol for adults is between 400mg and 800mg a day, split into 2 doses.
If your blood pressure is still too high, your doctor may increase your dose up to 2,400mg a day.
If your child is prescribed labetalol, the doctor will use your child's age and weight to work out the right dose.
Will my dose go up or down?
You'll usually start on a low dose of 100mg, taken twice a day.
You doctor may increase your dose every 1 to 2 weeks if the medicine is not controlling your high blood pressure or angina.
Once you find a dose that works for you, you'll usually stay with the same amount.
How to take it
Take labetalol with food. It'll be less likely to upset your stomach.
Swallow the tablets whole with a drink of water, juice or milk. Do not chew them.
What if I forget to take it?
If you miss a dose of labetalol, 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 as normal.
Never take 2 doses at the same time. Do not 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.
What if I take too much?
The amount of labetalol that can lead to an overdose varies from person to person.
Call your doctor or go to A&E straight away if you take too much labetalol
Taking more than your prescribed dose can slow down your heart rate and make it difficult to breathe.
It can also make you feel drowsy or confused.
If you need to go to A&E, do not drive yourself. Get someone else to drive you.
Take the labetalol packet or the leaflet inside the packet, plus any remaining medicine, with you.
Like all medicines, labetalol 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 go away by themselves.
Talk to your doctor or pharmacist if the side effects bother you or last more than a few days:
- feeling dizzy or weak
- itchy skin or a rash
- tingling scalp
- difficulty peeing
Serious side effects
It does not happen often, but some people have serious side effects when taking labetalol.
Tell a doctor straight away if you have:
- shortness of breath with a cough that gets worse when you exercise (like walking up stairs), swollen ankles or legs, chest pain and 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
- yellow skin or the whites of your eyes turn yellow - these can be signs of liver problems
Serious allergic reaction
In rare cases, labetalol may cause a serious allergic reaction (anaphylaxis).
Contact a doctor straight away if:
- 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
These are warning signs of a serious allergic reaction.
A serious allergic reaction is an emergency.
These are not all the side effects of labetalol.
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:
- feeling dizzy or weak - if labetalol 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 dizzy. Do not drink alcohol as it'll make you feel worse. Talk to your doctor if you feel dizzy all the time or this side effect lasts longer than a week.
- itchy skin or a rash - put a cold compress on the itchy area (you can make your own by wrapping a bag of frozen food in a towel). Have a shower or bath with cool or lukewarm water. You could also take an antihistamine, which you can buy from a pharmacy. Check with the pharmacist to see what type is suitable for you. Speak to your doctor if the itchiness or rash gets worse or it lasts for more than a week.
- 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 labetalol. Talk to your doctor if the headaches last longer than a week or are severe.
- tingling scalp - this should wear off in the first week or two as your body adjusts to the medicine. Talk to your doctor if this bothers you or does not go away. They may try you on a lower dose and then increase it gradually to a full dose.
- difficulty peeing - if this happens to you, speak to your doctor as soon as possible.
It's important to treat your high blood pressure during pregnancy. This will help you and your baby to stay healthy.
Talk to your doctor about the best treatment for your high blood pressure.
If your doctor recommends labetalol during your pregnancy, they'll prescribe the lowest dose that works for you.
Labetalol is not thought to harm an unborn baby. But there's a small chance that when your baby's born the medicine can affect their blood sugar levels.
For this reason your baby may be monitored for the first 24 hours to make sure everything is OK.
For more information about how labetalol can affect you and your baby during pregnancy, read this leaflet on the best use of medicines in pregnancy (BUMPS) website.
Labetalol and breastfeeding
If your doctor or health visitor says that your baby is healthy, it's OK to take labetalol while breastfeeding.
Labetalol passes into breast milk in very small amounts. It's unlikely to cause any side effects in your baby.
It's important to treat your high blood pressure to keep you well. Breastfeeding will also benefit both you and your baby.
If your baby's not feeding as well as usual, seems unusually sleepy, or you have any other concerns about them, talk to your doctor or health visitor.
Tell your doctor if you're:
- trying to get pregnant
There are some medicines that may interfere with the way labetalol works.
Tell your doctor if you're taking:
- other medicines for high blood pressure - when taken together with labetalol, this can sometimes lower your blood pressure too much; which may make you feel dizzy or faint. If this keeps happening to you, tell your doctor. They may change your dose.
- other medicines that can lower your blood pressure - these include some antidepressants, nitrates (for chest pain), baclofen (a muscle relaxant), medicines for an enlarged prostate, like tamsulosin, or medicines for Parkinson's disease, such as co-careldopa and levodopa
- medicines for your heart, such as amiodarone, flecainide or digoxin
- non-steroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen - they can stop labetalol working properly
- medicines for diabetes, particularly insulin - labetalol may make it more difficult to recognise the warning signs of low blood sugar. Speak to your doctor if you have low blood sugar levels without getting any of the usual warning signs. You should check your blood sugar after exercise, and follow the usual advice about checking it before driving or operating machinery.
- steroids like prednisolone
- cough medicines that contain pseudoephedrine or xylometazoline
- medicines for allergies, such as ephedrine, noradrenaline or adrenaline
- medicines for asthma or chronic obstructive pulmonary disease (COPD)
Mixing labetalol with herbal remedies or supplements
There might be a problem taking some herbal remedies and supplements together with labetalol, especially ones that cause side effects like low blood pressure.
Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.
How does labetalol work?
Labetalol is a type of medicine called a beta blocker.
Like other beta blockers, labetalol 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.
It also works like an alpha blocker to widen some of your blood vessels. This helps lower your blood pressure.
How long does labetalol take to work?
Labetalol starts to work after a few days to reduce high blood pressure.
If you're taking labetalol for high blood pressure, you may not feel any different. This does not mean the medicine's not working, and it's important to keep taking it.
If you're taking it for angina, it'll probably take a few days for the medicine to work.
You may still have chest pain during this time, and the pain may even get worse to start with.
Keep your spray or tablets for treating angina attacks with you at all times and use it if you need to.
How long will I take it for?
If you're taking labetalol for high blood pressure or angina, treatment is usually long term. You may take it for the rest of your life.
If you're taking it for high blood pressure during pregnancy, your midwife or doctor will check your blood pressure regularly.
They may increase or decrease your dose to keep your blood pressure under control.
If you need to keep taking labetalol after your baby is born, they'll keep checking your blood pressure and let you know when it's OK to stop taking your medicine.
Is it safe to take for a long time?
Labetalol is generally safe to take for a long time.
In fact, it works best when you take it for a long time.
If I take labetalol in pregnancy, will my child have behavioural problems?
You may have read about attention deficit hyperactivity disorder (ADHD) in children whose mothers took labetalol while they were pregnant.
But there's not enough evidence to say whether this is caused by taking labetalol or by taking any other type of medicine for high blood pressure.
Many more children need to be studied before we can say whether blood pressure medicines have any effect on their behaviour.
You can read more about labetalol in pregnancy on the best use of medicines in pregnancy (BUMPS) website.
What will happen if I stop taking it?
Talk to your doctor if you want to stop taking labetalol.
If you're bothered by side effects, your doctor may be able to prescribe a different medicine.
Stopping labetalol can make your blood pressure go up. This may increase your risk of heart attack and stroke.
To prevent this, your doctor will reduce your dose gradually over 1 to 2 weeks before you can stop taking it.
If you stop taking labetalol, it'll take a few days for it to be completely out of your body.
How does it compare with other heart medicines?
Labetalol works as well as other beta blockers for reducing blood pressure, but it starts working more quickly.
If you're pregnant, labetalol is the first choice for treating high blood pressure.
Labetalol works on the heart and on blood vessels. Other beta blockers, such as bisoprolol, work mainly on the heart.
There are several other medicines to lower blood pressure and treat chest pain.
They work in a different way from beta blockers, and include:
- ACE inhibitors like ramipril and lisinopril
- angiotensin receptor blockers (ARBs) like candesartan
- calcium channel blockers like amlodipine
- diuretics (medicines that make you pee more) like furosemide
Beta blockers are not usually the first-choice treatment for high blood pressure, except if you're pregnant.
The medicine your doctor prescribes depends on your age and ethnicity:
- if you're under 55, you'll usually be offered an ACE inhibitor or an angiotensin receptor blocker
- if you're 55 or older, or you're any age and of black African or Caribbean origin, you'll usually be offered a calcium channel blocker
Sometimes you may have to try other blood pressure medicines if you get side effects.
Many people need to take a combination of different blood pressure-lowering tablets.
Will I need to stop labetalol before surgery?
Tell your doctor that you're taking labetalol 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 labetalol for 24 hours before surgery.
This is because labetalol can lower your blood pressure too much when it's combined with some anaesthetics.
Can I drink alcohol with it?
Drinking alcohol can increase the risk of side effects with labetalol. It can make you feel dizzy or lightheaded.
During the first few days of taking labetalol 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 labetalol makes you feel dizzy, it's best to stop drinking alcohol.
Is there any food or drink I need to avoid?
You can eat and drink normally while taking labetalol.
Will it affect my contraception?
Labetalol will not stop your contraception working.
Talk to your doctor if you're taking a combined hormonal contraceptive.
Will it affect my fertility?
There's no firm evidence to suggest that taking labetalol will reduce fertility in either men or women.
If you're trying for a baby or having problems getting pregnant while on labetalol, speak to your doctor.
Will it affect my sex life?
Some people on labetalol say their sex drive goes down and some men say they canot get an erection.
There's not enough evidence to say for sure that labetalol is causing this.
If you're having problems with your sex life, talk to your doctor.
Do I need to avoid playing sports?
You do not need to stop playing sports if you take labetalol. But do not 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 labetalol is not allowed if you're competing at a high level.
Can I drive or ride a bike?
Labetalol 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 until you feel OK again.
Can lifestyle changes help?
You can boost the health of your heart by making some key lifestyle changes.
These will also help if you have high blood pressure:
- quit smoking, or find out how to stop smoking in pregnancy
- cut down on alcohol, or find out about drinking alcohol while pregnant
- exercise regularly, or find out about exercise in pregnancy
- eat well and cut down on salt, or find out how to have a healthy diet in pregnancy
- deal with stress - when you're anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up