Metoprolol: uses, doses, side effects and cautions

The NHS lists high blood pressure, conditions that cause an irregular heartbeat, prevention of heart disease, heart attacks and strokes, prevention of angina chest pain, migraine prevention and reducing symptoms of thyrotoxicosis. It belongs to the beta blocker class and slows the heart rate so the heart pumps more easily. Tablets are prescription only.

These are the typical adult figures given. Your own dose depends on your condition and response, so follow your prescriber.

Swallow tablets whole with water, with or without food. Space multiple daily doses evenly. If the first dose makes you dizzy, taking it at bedtime is suggested; if well tolerated, you can then switch to the morning.

For heart conditions and high blood pressure you may need it for the rest of your life, while migraine prevention may last several months to years. If you miss a dose, take it when you remember unless the next is near, in which case skip it. Never double up. Call NHS 111 if you take more than prescribed; symptoms of too much include slow heart rate, breathing difficulty, dizziness and trembling.

Stopping metoprolol suddenly can make your condition worse, so talk to your doctor first. The medicine leaves the body in one to two days.

Say if you have ever had an allergic reaction to metoprolol, low blood pressure or a slow heart rate, lung disease or severe asthma, metabolic acidosis, an overactive thyroid (metoprolol may hide its warning signs), severe circulation problems such as Raynaud syndrome, or liver conditions. Tell your doctor before any surgery needing general anaesthetic, as blood pressure can fall too far with some anaesthetics.

Headaches, tiredness, dizziness, nausea, stomach pain, vomiting and diarrhoea are the main ones, typically mild and short lived. Rest and drink fluids for headaches, avoid driving or machinery when tired or dizzy, and avoid smoking and caffeine if your fingers and toes feel cold. Keep meals simple for nausea.

Call NHS 111 or a doctor for heart problems, thyroid symptoms or unusual bruising. Call 999 for chest pain that does not settle, severe breathlessness or wheezing, or signs of a serious allergic reaction.

Named medicines: other blood pressure medicines, antidepressants, nitrates, baclofen, tamsulosin, co-careldopa and levodopa, NSAIDs such as ibuprofen, diabetes medicines, and ephedrine, noradrenaline and adrenaline. Some herbal remedies, especially ones that lower blood pressure, may be a problem. The NHS advises against alcohol as it may worsen symptoms such as dizziness.

You may take metoprolol in pregnancy, but it can sometimes affect the baby's growth and extra growth scans are usual, generally from 32 weeks. It is among the preferred options for high blood pressure while breastfeeding a healthy baby, as it passes into breast milk in very small amounts and has not been known to cause side effects. No evidence shows it reduces fertility. Report suspected side effects via the Yellow Card scheme.