Minoxidil for high blood pressure

About minoxidil

Although many people with high blood pressure (hypertension) do not feel unwell, it is still important that high blood pressure is treated. If left untreated, high blood pressure is a risk factor that can increase your chance of developing heart disease, a stroke and other serious conditions. Minoxidil will be prescribed for you if other medicines have not been sufficient to control your high blood pressure. It will be prescribed for you by a specialist doctor.

Minoxidil works by relaxing the muscles in the walls of your blood vessels. This means that your blood vessels widen, which reduces your blood pressure and allows blood and oxygen to circulate more freely around your body. You will also be prescribed other medicines to take alongside minoxidil. These are to help regulate the amount of water and salt in your body and also to help control your heart rate because these can be increased by taking minoxidil.

Minoxidil is also used in scalp applications for the treatment of hair loss. For more information about this please see our other leaflets on minoxidil scalp preparations for men and for women.

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 minoxidil it is important that your doctor knows:

• If you have any problems with the way your kidneys work.

• If you have angina chest pain, or if you have recently had a heart attack.

• If you have a rare inherited blood disorder called porphyria.

• If you have been told you have a tumour known as phaeochromocytoma.

• 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.

• If you are pregnant or breastfeeding. Minoxidil is generally unsuitable for women; however, if it has been prescribed for you and you are pregnant or breastfeeding, you must make sure your doctor knows about this.

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

• Take minoxidil exactly as your doctor tells you to. Your doctor will tell you how many tablets to take each day, and your dose will also be printed on the label of the pack to remind you about what the doctor said to you. It is usual to take minoxidil tablets either once or twice every day.

• Try to take your doses at similar times of day each day, as this will help you to remember to take them regularly. There are three strengths of tablet available: 2.5 mg, 5 mg, and 10 mg. It is usual to take a low-strength tablet to begin with and for this to increase as you go on. Increasing your dose gradually allows your doctor to make sure that you have the dose that best helps your condition but also keeps unwanted side-effects to a minimum.

• Swallow the tablet whole with a drink of water. You can take minoxidil either before or after a meal.

• If you forget to take a dose at your usual time, take it as soon as you remember unless your next dose is due. If your next dose is due then take the dose which is due but leave out the forgotten one. Do not take two doses together to make up for a missed dose.

• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. You will need to have regular blood pressure measurements and also some heart and blood tests from time to time.

• Your doctor will discuss with you the possibility of unwanted side-effects of treatment, such as your fine body hair becoming darker and thicker. This may be noticed about a month or so after starting treatment with minoxidil. Because of this effect, minoxidil is generally unsuitable for women but if it has been prescribed for you and you could get pregnant, you should ask your doctor about what methods of contraception are suitable for you. This is because you should avoid becoming pregnant while you are on minoxidil.

• Your doctor will advise you on what lifestyle changes you can make to help your condition. These may include losing weight if you are overweight, taking regular physical activity, eating a healthy diet, cutting back if you drink a lot of alcohol, stopping smoking, and reducing the amount of salt in your meals and caffeine in your drinks. It is important that you follow any advice you are given.

• If you are due to have an operation or dental treatment, tell the person carrying out the treatment that you are taking minoxidil. This is because some anaesthetics can affect your blood pressure.

• If you buy any medicines, check with a pharmacist that they are suitable for you to take. This is because some medicines (particularly some anti-inflammatory painkillers) can interfere with minoxidil.

• Treatment with minoxidil is usually long-term unless you experience an adverse effect. You should continue to take the tablets regularly unless you are advised otherwise by your doctor.

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