Carvedilol is a beta blocker.

It’s used to treat high blood pressure (hypertension) and helps prevent:

• heart disease
• heart attacks
• strokes

It can also be given with other medicines to treat heart failure and to prevent chest pain caused by angina.

Carvedilol is only available on prescription. It comes as tablets.

• Carvedilol slows down your heart rate and makes it easier for your heart to pump blood around your body.
• You’ll usually take carvedilol once or twice a day.
• It usually starts to work after about 1 hour. But it will take days or weeks for it to reach its full effect.
• Common side effects of carvedilol include headaches and feeling tired or dizzy.
• Do not stop taking carvedilol suddenly. This can make your condition worse, especially if you have heart disease.

Carvedilol can be taken by most adults. It can sometimes be prescribed by a specialist for children aged 2 years and over.

Carvedilol is not suitable for some people. Tell your doctor before starting the medicine if you have:

• ever had an allergic reaction to carvedilol or any other medicines
• lung disease or asthma
• heart failure that is getting worse
• have low blood pressure (hypotension) or a slow heart rate
• a liver problem
• serious circulation problems in your arms and legs, such as Raynaud’s

When you start taking carvedilol, your doctor may advise you to take your first dose just before you go to bed. This is because it can make you feel dizzy.

After the first dose, if you do not feel dizzy, you can take your medicine in the morning. If you do feel dizzy, it’s best to keep taking your medicine at bedtime.

It’s best to take carvedilol at the same time each day.

If you take it twice a day, you’ll usually have 1 dose in the morning and 1 dose in the evening. Leave 10 to 12 hours between doses if you can.

Swallow the tablets whole with a drink of water. Do not chew or crush them.

Carvedilol does not usually upset your stomach, so you can take it with or without food. However, if you are taking carvedilol for heart failure, it’s best to take the tablets with food. This will help reduce the risk of you feeling dizzy or faint when you stand up.

If you find tablets difficult to swallow, some strengths have a score line to help you break the tablet in half. Check the information leaflet that comes with your medicine to see if you can do this.

Dosage

Carvedilol tablets come in 4 different strengths – 3.125mg, 6.25mg, 12.5mg and 25mg.

How much you take depends on why you need carvedilol.

The usual starting dose to treat:

• high blood pressure is 12.5mg once a day for 2 days – this is increased to 25mg, taken once a day. If your blood pressure does not go down enough your doctor may increase your dose to up to 50mg a day. This can be taken as a single dose or split into 2 doses.
• heart failure is 3.125mg, taken twice a day for 2 weeks. Your doctor will then slowly increase the dose every 2 weeks up to a maximum of 25mg to 50mg (depending on your weight).
• angina is 12.5mg, taken twice a day for 2 days – this is increased to 25mg, taken twice a day.

If your child is prescribed carvedilol, the doctor will use their weight to work out the right dose.

What if I forget to take it?

If you miss a dose of carvedilol, 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. 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.

What if I take too much?

The amount of carvedilol that can lead to an overdose varies from person to person.

Taking too much carvedilol can lower your blood pressure, slow your heart rate, and make it difficult to breathe.

Like all medicines, carvedilol can cause side effects in some people, but many people have no side effects or only minor ones.

Side effects usually improve as your body gets used to the medicine.

Common side effects

These common side effects may happen in more than 1 in 100 people. They’re usually mild and last a few days after starting the medicine or increasing your dose.

Talk to your doctor or pharmacist if these side effects bother you or do not go away:

• feeling dizzy
• headaches
• feeling tired
• feeling or being sick (nausea or vomiting)
• cold fingers or toes

Serious side effects

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

Tell a doctor straight away if you have:

• nose bleeds that last for more than 10 minutes, unexplained bruising, or you bruise more easily than usual – these can be signs of low numbers of platelets in your blood (thrombocytopenia)
• high temperature, sore throat, mouth sores, toothache, flu-like symptoms – these can be signs of a low number of white blood cells (leukopenia)
• shortness of breath with a cough that gets worse when you exercise (like walking up the stairs), swollen ankles or legs, chest pain, or an irregular heartbeat – these may be signs of other heart problems
• shortness of breath, wheezing and tightening of your 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, it's possible to have a serious allergic reaction (anaphylaxis) to carvedilol.

What to do about:

• feeling dizzy – as your body gets used to carvedilol this side effect should wear off. If carvedilol makes you feel dizzy, stop what you’re doing and sit or lie down until you feel better. Do not drive or operate machinery until you feel OK again. Try to avoid alcohol as it'll make you feel worse.
• headaches – make sure you rest and drink plenty of fluids. Ask your pharmacist to recommend a painkiller. Do not drink too much alcohol. Headaches usually go away after the first week of taking carvedilol. Talk to your doctor if the headaches last more than a week or are severe.
• feeling tired – do not drive, ride a bike, or use tools or machinery if you’re feeling tired. Do not drink any alcohol as this will make you feel more tired.
• feeling sick or being sick – stick to simple meals and do not eat rich or spicy food. It might help to take your carvedilol after a meal or snack. If you're being sick, try drinking small, frequent sips of water to avoid dehydration.
• cold fingers or toes – 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, as this can make your blood vessels narrower and restrict your blood flow. It’s best not to wear tight watches or bracelets as well. Try wearing mittens (they're warmer than gloves) and warm socks. Speak to your doctor if this side effect bothers you.

Carvedilol is not usually recommended if you’re pregnant.

If you're trying to get pregnant or you're already pregnant, talk to your doctor about taking carvedilol. It may be possible to change to other medicines that are more suitable when you’re pregnant, such as labetalol or nifedipine.

Carvedilol and breastfeeding

If your doctor or health visitor says that your baby is healthy, it's OK to take carvedilol while breastfeeding.

There is no information about whether carvedilol passes into breast milk, but it would only be expected to pass through in small amounts. It’s unlikely to cause any side effects in your baby.

If you notice that your baby isn't feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, then talk to your health visitor, midwife or doctor as soon as possible.

Find out more about high blood pressure and pregnancy.

There are some medicines that can affect the way carvedilol works.

Tell your doctor if you’re taking:

• other medicines for high blood pressure – when taken together with carvedilol, they can sometimes lower your blood pressure too much
• 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 gland like tamsulosin, or levodopa (for Parkinson’s disease)
• medicines for an irregular heartbeat such as amiodarone or flecainide
• medicines for asthma or chronic obstructive pulmonary disease (COPD)
• medicines for diabetes, particularly insulin – carvedilol 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 warning signs. You should check your blood sugar after exercise, and follow usual advice about checking it before driving, or operating machinery.
• medicines that treat nose or sinus congestion, or other cold remedies (including those you can buy in the pharmacy)
• medicines for allergies, such as ephedrine, noradrenaline or adrenaline
• non-steroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen, diclofenac and naproxen – these medicines may increase your blood pressure

Mixing carvedilol with herbal remedies and supplements

There's very little information about taking herbal remedies and supplements with carvedilol. However, some herbal products, such as cod liver oil, hawthorn and garlic tablets may cause low blood pressure (hypotension).