Metoprolol - a beta-blocker

Metoprolol belongs to the group of medicines known as beta-blockers. It is a medicine which is used to treat several different medical conditions. It works on the heart and blood vessels.

Metoprolol slows down the activity of your heart by stopping messages sent by some nerves to your heart. It does this by blocking tiny areas (called beta-adrenergic receptors) where the messages are received by your heart. As a result, your heart beats more slowly and with less force. This allows the pressure of blood within your blood vessels to be reduced if you have high blood pressure (hypertension), and helps to prevent abnormally fast heart rhythms (arrhythmias). Because your heart is using less energy, this helps to reduce chest pain if you have angina. Metoprolol can also help to protect the heart following a heart attack.

Metoprolol is also prescribed to help ease some of the symptoms of an overactive thyroid gland, such as a fast heartbeat and trembling. It relieves these symptoms quickly, which allows time for other antithyroid treatments to take effect. Metoprolol is also prescribed to help prevent migraines. It can be helpful for people who find other treatments for migraine unsuitable.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking metoprolol it is important that your doctor or pharmacist knows:

• If you are pregnant, trying for a baby or breast-feeding.
• If you have asthma or any other breathing disorder.
• If you have any problems with the way your liver works.
• If you have low blood pressure or poor circulation.
• If you have high blood sugar levels (diabetes mellitus).
• If you have a skin problem called psoriasis.
• If you have a condition causing muscle weakness, called myasthenia gravis.
• If you have been told you have a slow heartbeat or heart block (a slow and irregular heartbeat).
• If you have been told you have chest pain called Prinzmetal's angina (caused by spasms of your heart's blood vessels).
• If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine, or if you have ever had any other serious allergic reaction.

• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.
• Treatment with metoprolol can often be long-term. Continue to take the tablets unless your doctor tells you to stop. Stopping treatment suddenly can cause problems in some people, so your doctor may want you to reduce your dose gradually if this becomes necessary.
• If you are due to have an operation or dental treatment, it is important to tell the person carrying out the treatment that you are taking a beta-blocker. This is because some anaesthetics may increase the risk of unwanted effects.
• If you drink alcohol, ask your doctor for advice about taking metoprolol and alcohol. Alcohol will add to the blood pressure-lowering effect of metoprolol and so may not be recommended for you.
• If you buy any medicines, check with a pharmacist that they are suitable for you to take. Some medicines (including some cough, cold and flu remedies) may not be.
• Your doctor may give you dietary and lifestyle advice about eating a healthy diet, not smoking, and taking regular exercise. If so, it is important that you follow the advice you are given.
• If you have diabetes, metoprolol can block the symptoms of low blood sugar. Your doctor will advise you about this.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with metoprolol. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

• Keep all medicines out of the reach and sight of children.
• Store in a cool, dry place, away from direct heat and light.