Carvedilol is a type of medicine called a beta-blocker.
What is it used for?
- Chronic, stable heart failure, in addition to standard medicines used to treat heart failure.
- Angina pectoris (as a regular treatment to prevent attacks).
- High blood pressure (hypertension).
How does it work?
- Carvedilol is a type of medicine called a beta-blocker.
- Beta-blockers work by blocking beta receptors that are found in various parts of the body, including the heart. Blocking the beta receptors prevents the action of two hormones that are produced naturally by the body, called noradrenaline and adrenaline. These hormones are often referred to as the 'fight or flight' chemicals, because they are responsible for the body's reaction to stressful situations.
- Carvedilol blocks beta receptors that are found in the heart. This reduces the action of adrenaline and noradrenaline on the heart, causing it to beat more slowly and with less force.
How do I take it?
- Carvedilol tablets should be swallowed with a drink of water. If you are taking this medicine for chronic heart failure then you should take the tablets with food.
- The dose prescribed and how often the medicine needs to be taken depends on the condition being treated. The tablets are usually taken once or twice daily. It is important to follow the instructions given by your doctor and printed on the dispensing label.
- Try to always take your doses at the same times. This will help you remember to take them.
- If you forget to take a dose, take it as soon as you remember, unless it is almost time to take your next dose. In this case, skip the missed dose and take your next dose when it is due. Do not take a double dose to make up for a missed dose.
- It is important that you don't suddenly stop taking this medicine unless your doctor tells you to.
Use with caution in
- Elderly people.
- Decreased kidney function.
- People with a history of heart failure or a weak heart (see warning above).
- Slowed conduction of electrical messages between the chambers of the heart (1st degree heart block).
- A severe form of chest pain not caused by exertion (Prinzmetal's or variant angina).
- Conditions involving poor blood circulation in the arteries of the extremities, eg hands and feet (peripheral arterial disorders such as Raynaud's syndrome or intermittent claudication).
- Diabetes (this medicine may mask the symptoms of low blood sugar, such as increased heart rate and tremor, and the dose of your diabetes medicine may need adjusting).
- People with a history of sudden drops in blood sugar levels (hypoglycaemia).
- Overactive thyroid gland (this medicine may mask the symptoms of a thyroid storm or thyrotoxicosis).
- Abnormal muscle weakness (myasthenia gravis).
- People with a history of allergies (beta-blockers may increase sensitivity to allergens and result in more serious allergic reactions; they may also reduce the response to adrenaline used to treat anaphylactic shock).
Not to be used in
- People with a serious defect in the heart's electrical message pathways resulting in decreased function of the heart (2nd or 3rd degree heart block).
- Uncontrolled heart failure.
- People with a very slow heart rate (bradycardia - less than 50 beats per minute).
- A problem common in the elderly, related to poor control of the working of the heart (sick sinus syndrome).
- Failure of the heart to maintain adequate circulation of blood around the body (cardiogenic shock).
- Decreased liver function.
- Very low blood pressure (hypotension).
- Fluid retention that requires treatment with intravenous heart medicines, such as digoxin.
- Chronic obstructive pulmonary disease (COPD).
- History of asthma, wheezing or any other breathing difficulties.
- People with an increase in the acidity of the blood (metabolic acidosis).
- Untreated tumour of the adrenal gland (phaeochromocytoma). If you are being treated for phaeochromocytoma you will be given another medicine called an alpha-blocker in combination with this one.
- Children and adolescents under 18 years old.
This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- The manufacturer states that this medicine should not be used during pregnancy unless considered essential by your doctor. Beta-blockers reduce blood flow to the placenta, which could increase the chance of premature delivery or death of the foetus. They may also slow the baby's heartbeat, cause its blood sugar to drop, or restrict its growth in the womb. If you think you could be pregnant while taking this medicine, or want to try for a baby, it is important to seek medical advice from your doctor. It is important that you don't stop taking this medicine suddenly.
- This medicine may pass into breast milk in small amounts. As this could potentially cause the baby's heart rate to slow down or its blood sugar to fall, it is recommended that this medicine is not used by breastfeeding mothers. Seek medical advice from your doctor.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
Very common (affect more than 1 in 10 people)
- Feeling tired.
- Low blood pressure.
- Decreased ability of the heart to pump blood efficiently.
Common (affect between 1 in 10 and 1 in 100 people)
- Chest infections.
- Urinary tract infections.
- Slower than normal heart beat (bradycardia).
- Fluid retention.
- Weight gain.
- Raised cholesterol levels.
- Changes in blood sugar, particularly in people with diabetes.
- Dry or irritated eyes.
- Visual disturbances.
- Drop in blood pressure when moving from a lying or sitting position to sitting or standing, which may cause dizziness, light-headedness or fainting.
- Cold hands and feet.
- Pain in the hands and feet.
- Cramping pain in the leg (calf) muscles on exertion (intermittent claudication).
- Narrowing of the blood vessels in the hands leading to periods of white, painful hands (Raynaud's disease).
- Disturbances of the gut such as nausea, diarrhoea, vomiting, abdominal pain or indigestion.
- Problems with kidney function.
Uncommon (affect between 1 in 100 and 1 in 1000 people)
- Sexual problems such as impotence.
- Skin reactions such as rash, itching, hives, increased sweating, dermatitis or dry skin.
- Hair loss.
- Problems with the electrical pathways that control the pumping action of the heart (heart block).
- Sensation of pins and needles in hands and feet.
- Sleep disturbances.
Rare (affect between 1 in 1000 and 1 in 10,000 people)
- Nasal congestion.
- Flu-like symptoms.
- Dry mouth.
- Reduced platelet count in the blood (thrombocytopenia).
Very rare (affect less than 1 in 10,000 people)
- Urinary incontinence in women (this will get better if treatment with this medicine is stopped).
- Decrease in the number of white blood cells (leukopenia).
- Changes in liver enzyme levels.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.
Carvedilol is likely to have an additive effect with other medicines that decrease blood pressure, particularly medicines that are used to treat high blood pressure (antihypertensives). This may cause dizziness, which can usually be relieved by lying down until the symptoms pass. If you feel dizzy while taking this medicine in combination with other medicines that can lower blood pressure you should let your doctor know, as your doses may need adjusting.
Other medicines that decrease blood pressure include the following:
- ACE inhibitors, eg enalapril
- alpha-blockers such as prazosin
- angiotensin II receptor antagonists such as losartan
- antipsychotics such as chlorpromazine
- benzodiazepines, eg temazepam, diazepam
- other beta-blockers such as propranolol
- calcium channel blockers such as verapamil, nifedipine. (If carvedilol is taken with calcium channel blockers such as verapamil, nifedipine or diltiazem, there may also be an increased risk of slow heart rate and heart failure. Verapamil must not be given as an injection into a vein (intravenously) to people being treated with carvedilol.)
- clonidine (If carvedilol is taken in combination with clonidine there is also a risk of a rebound increase in blood pressure if the clonidine is suddenly stopped. If you are taking both these medicines it is important to keep taking both of them unless otherwise directed by your doctor. When stopping treatment, the carvedilol should be stopped several days before slowly stopping the clonidine.)
- diuretics, eg furosemide, bendroflumethiazide
- dopamine agonists, eg bromocriptine, apomorphine
- MAOI antidepressants, eg phenelzine
- nitrates, eg glyceryl trinitrate
This medicine may reduce the blood sugar lowering effect of some medicines used to treat diabetes. People with diabetes should carefully monitor their blood sugar while taking this medicine, as carvedilol can also mask some of the signs of low blood sugar, such as increased heart rate and tremor.
There may be an increased risk of slow heart rate and heart block if carvedilol is used in combination with the following medicines:
- medicines for irregular heartbeats (anti-arrhythmics), eg amiodarone, flecainide, quinidine
Carvedilol may increase the blood levels of the following medicines. If you are taking either of these with carvedilol your doctor may want to check your blood levels more often:
- The antibiotic rifampicin may decrease the blood level of carvedilol.
The following medicines may reduce the blood pressure lowering effect of this medicine:
- corticosteroids, such as dexamethasone or prednisolone
- oestrogens, such as those in the contraceptive pill
- regular use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, diclofenac or indomethacin (occasional painkilling doses are unlikely to have a significant effect).