Carvedilol: uses, doses, side effects and cautions

Carvedilol treats high blood pressure and helps prevent heart disease, heart attacks and strokes. With other medicines it is used for heart failure and to prevent angina chest pain. As a beta blocker it slows the heart rate and makes it easier for the heart to pump blood around the body.

The NHS says it usually starts to work after about an hour but takes days or weeks to work fully, so early blood pressure readings may not show its eventual effect.

Carvedilol is started low and stepped up. The NHS gives these typical schedules for adults.

Swallow tablets whole with water; do not chew or crush them, though some can be broken in half if the label allows. In heart failure, take it with food to prevent dizziness; otherwise food does not matter. Keep to the same times each day, and if you take it twice daily leave 10 to 12 hours between doses. Initial doses are taken before bed because of the dizziness risk.

Treatment is usually long term and may be needed for life. If you miss a dose, take it when you remember unless the next is near, and never double up. Call NHS 111 if you take more than prescribed. Do not stop suddenly.

Tell the prescriber if you have ever had an allergic reaction to carvedilol or another medicine, have lung disease or asthma, heart failure that is getting worse, low blood pressure or slow heart rate, a liver problem, or serious circulation problems in arms and legs such as Raynaud phenomenon.

Sleepiness, tiredness and dizziness are common: stop what you are doing and sit or lie down until you feel better, and do not drive, cycle or use machinery. Cold fingers or toes can be eased with warm running water and massage. For nausea or vomiting, keep meals simple, and taking carvedilol after a meal may help. Drink fluids if you have diarrhoea.

Call NHS 111 or a doctor for nosebleeds lasting over 10 minutes, unexplained bruising, shortness of breath with a cough or swollen ankles. Call 999 for chest pain lasting several minutes with sweating or nausea, shortness of breath with wheezing and chest tightness, or signs of a serious allergic reaction. Avoid alcohol if you feel dizzy because it will make you feel worse.

Named medicines include other blood pressure medicines, nitrates, baclofen, tamsulosin, levodopa, digoxin, amiodarone and flecainide, asthma and COPD medicines, insulin and diabetes medicines, nasal decongestants and cold remedies, ephedrine, noradrenaline and adrenaline, NSAIDs such as ibuprofen, diclofenac and naproxen, and ciclosporin. The NHS says there is not enough information to say herbal remedies are safe with carvedilol.

Carvedilol is not typically advised in pregnancy; the NHS says similar medicines with more safety information, such as labetalol or nifedipine, are available. It is generally safe while breastfeeding a healthy baby because levels in milk are likely to be low. There is no evidence it reduces fertility. Report suspected side effects via the Yellow Card scheme.