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Methyldopa for high blood pressure

Aldomet

Take methyldopa at the same times each day. It is usual to be prescribed two or three doses to take a day.

Methyldopa can make you feel sleepy, particularly during the first two or three days. Do not drive and do not use tools or machines while affected.

Continue to take methyldopa tablets until you are advised otherwise by your doctor.

At a glance

  • Methyldopa is a medicine used to treat high blood pressure.

  • It is often used to treat high blood pressure during pregnancy.

  • Take methyldopa exactly as your doctor tells you, usually two or three times a day.

  • Do not drink alcohol, as it can increase side-effects like sleepiness or dizziness.

  • You will need regular blood tests to check your liver function.

  • See your doctor if you get an unexplained high temperature or yellow skin or eyes.

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About methyldopa

Type of medicine

A centrally acting antihypertensive medicine

Used for

High blood pressure (hypertension)

Also called

Aldomet®

Available as

Tablets

Most people with high blood pressure (hypertension) do not feel unwell, but it is important that your high blood pressure is treated even if you feel fine. This is because high blood pressure can be damaging to your blood vessels and can put a strain on your heart. By lowering your blood pressure, methyldopa reduces your cardiovascular risk.

Methyldopa is one of the medicines of choice for treating high blood pressure in pregnancy. When taken during pregnancy, treatment with methyldopa is reviewed soon after the birth of the baby, as other treatment options are then likely to be more suitable.

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

  • If you have any problems with the way your liver works, or any problems with the way your kidneys work.

  • If you have ever had a depressive illness.

  • If you have been told you have any of the following rare conditions: an adrenaline-producing growth called a phaeochromocytoma or a paraganglioma, or an inherited blood disorder called porphyria.

  • If you are taking or using 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.

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  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about methyldopa and will provide you with a full list of the side-effects which you may experience from taking it.

  • Take methyldopa exactly as your doctor tells you to. It is usual to start by taking 250 mg two or three times daily. Your doctor may increase your dose after a few days if it is necessary. Each time you see your doctor you will be told how many tablets to take for each dose, and this information will also be printed on the label of the pack of tablets to remind you about what the doctor said to you.

  • Try to take your doses at the same times of day each day, as this will help you to remember to take them regularly. You can take your doses either before or after food. Swallow the tablet with a drink of water.

  • If you forget to take a dose, take it as soon as you remember. Try to take the correct number of doses each day but do not take two doses at the same time to make up for a missed dose.

  • Try to keep your regular appointments with your doctor so your progress can be monitored. Your doctor will want you to have blood tests from time to time to make sure your liver is working properly.

  • There are three strengths of methyldopa tablet available - 125 mg, 250 mg and 500 mg. Each time you collect a fresh supply of tablets it is a good idea to check to make sure you receive the strength you are expecting. If you have any questions, please ask your pharmacist to advise you.

  • 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.

  • Drinking alcohol while you are on methyldopa is not recommended. It can increase the chance that you will experience side-effects, such as feeling sleepy or dizzy.

  • If you buy any medicines 'over the counter', please check with a pharmacist that they are suitable for you to take with methyldopa. Some medicines, such as some anti-inflammatory painkillers, can interfere with the way methyldopa works.

  • If you are due to have an operation or dental treatment, tell the person carrying out the treatment that you are taking methyldopa. This is because some anaesthetics can affect your blood pressure. Also, before having any medical tests, tell the person carrying out the test that you are taking methyldopa, as the results of some tests can be affected by it.

  • Continue to take methyldopa tablets until you are advised otherwise by your doctor.

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Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the common ones associated with methyldopa. 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.

Common methyldopa side-effects

What can I do if I experience this?

Feeling sleepy, weak, or tired

This can happen during the first few days of treatment and if your dose is increased. Increase your evening dose first. Do not drive and do not use tools or machines while affected. Do not drink alcohol

Headache

Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know

Important: if you develop a high temperature which you can't explain, or if you notice any yellowing of your skin or of the whites of your eyes (jaundice), speak with your doctor as soon as possible. Occasionally, some people taking methyldopa have had blood or liver problems and your doctor will want you to have a blood test to check for these.

If you experience any other symptoms which you think may be due to the tablets, 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.

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

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Unsure about mixing medicines?

Check for possible interactions between medicines, supplements and foods before taking them together.

Frequently asked questions

Why is it important to take methyldopa if I feel well?

Even if you don't feel unwell, high blood pressure can damage your blood vessels and strain your heart. Methyldopa helps lower your blood pressure, which reduces your risk of cardiovascular problems.

Can I take other medicines alongside methyldopa, including over-the-counter ones?

You should tell your doctor about all medicines you are taking, including those available without a prescription, and herbal remedies. When buying over-the-counter medicines, always check with a pharmacist to ensure they are suitable to take with methyldopa, as some, like certain anti-inflammatory painkillers, can affect how methyldopa works.

What should I do if I forget a dose of methyldopa?

If you forget a dose, take it as soon as you remember. However, do not take two doses at the same time to make up for a missed dose. The goal is to take the correct number of doses each day.

Do I need to make any changes to my diet or lifestyle while taking methyldopa?

Your doctor might advise you on dietary and lifestyle changes, such as eating a healthy diet, not smoking, and exercising regularly. It's important to follow any advice they give you. Also, drinking alcohol is not recommended as it can increase side-effects like feeling sleepy or dizzy.

How long will I need to take methyldopa?

You should continue to take methyldopa tablets until your doctor advises you otherwise. Do not stop taking it without your doctor's instruction.

What should I be aware of before having an operation, dental treatment, or medical tests?

Always inform the person carrying out the treatment or test that you are taking methyldopa. This is because some anaesthetics can affect your blood pressure, and methyldopa can affect the results of some medical tests.

What should I do if I experience a high temperature or yellowing of my skin/eyes?

If you develop an unexplained high temperature, or if you notice any yellowing of your skin or the whites of your eyes (jaundice), you should speak with your doctor as soon as possible. These could be signs of blood or liver problems, and your doctor will want to perform a blood test to check.

Further reading and references

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About the authorView full bio

Author image

Michael Stewart, MRPharmS

Medicine Leaflet Review Manager – Contractor, Pharmacist

BPharm (Hons), MRPharmS

Michael is a community pharmacist practicing in the Midlands and South Yorkshire with more than 20 years’ experience advising on medicines and medical conditions. He has a strong background in healthcare training, having produced and delivered training courses for pharmacy teams and staff of residential care settings, including nurses. He has also contributed to pharmacy advisory boards for the management of low acuity conditions in the community.

About the reviewer

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Sid Dajani

Sultan Dajani qualified at the London School of Pharmacy in 1994 and became the youngest elected member of the Royal Pharmaceutical Society council since its founding in 1842.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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