Doxazosin

NHS information about the medicine doxazosin, including what it's used for, who can take it, how to take it and side effects.

What doxazosin is for

Doxazosin is used to:

• lower high blood pressure (hypertension), which can reduce the risk of heart attack and stroke
• treat the symptoms of an enlarged prostate, such as problems with peeing

Doxazosin is a type of medicine called an alpha blocker.

It works by widening your blood vessels, making it easier for blood to move around your body. It also relaxes the muscles around the prostate and bladder, which can make it easier to pee.

How to take doxazosin

Doxazosin comes as a tablet that you swallow.

You'll usually need to take it once a day, at the same time every day, with a drink of water.

Your doctor will tell you how much to take and for how long. Doxazosin treatment is often long term, and you'll probably need to take it for several years

Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.

If you miss a dose of doxazosin

If you miss a dose of doxazosin, take it as soon as you remember, unless it's nearly time for your next dose.

If it's nearly time for your next dose, skip the dose you missed and take your next dose at the usual time.

Do not take 2 doses to make up for a missed dose.

If you take too much doxazosin

Taking an extra dose of doxazosin can be be dangerous.

Side effects of doxazosin

Like all medicines, doxazosin can cause side effects, although not everyone gets them.

Common side effects

Common side effects of doxazosin include:

• headaches, dizziness and feeling like everything around you is spinning (vertigo)
• swelling, usually in your ankles, feet and legs (oedema)
• cold-like symptoms, such as sneezing, or flu-like symptoms, such as a high temperature and an aching body
• tummy pain
• feeling sick (nausea) and being sick (vomiting)

If you feel dizzy or get vertigo after taking doxazosin, do not drive, ride a bike or use machinery until you no longer have these symptoms.

These are not all the side effects of doxazosin.

For a full list, see the leaflet inside your medicines packet, or search for your medicine leaflet on the electronic medicines compendium website.

You can report any side effects you get on the Yellow Card Scheme website

Who can and cannot take doxazosin

Most adults can take doxazosin. It may also be given by a specialist to children to treat high blood pressure or bladder problems.

Doxazosin is not suitable for everyone. For example, it may not be suitable if:

• you've had an allergic reaction or serious side effects from doxazosin
• you have an enlarged prostate and low blood pressure
• you have an enlarged prostate and bladder or kidney problems
• you've been told you have orthostatic hypotension (you get dizzy and light-headed when you stand up)

Before taking doxazosin, tell your doctor or a pharmacist if you have any medical conditions.

Breastfeeding and doxazosin

Tell your doctor if you're breastfeeding.

Doxazosin passes into breast milk in very small amounts. A doctor may recommend you breastfeed if the benefits outweigh the risks.

If you're taking doxazosin while breastfeeding, speak to a healthcare professional or call NHS 111 if you have any concerns about your baby.

Pregnancy and doxazosin

Tell your doctor if you're pregnant. Doxazosin is not usually used during pregnancy as not enough is known about its safety.

But a doctor may recommend it if the benefits outweigh the risks.

Taking doxazosin with other medicines, food and drink

There are some medicines, remedies and supplements that may not mix well with doxazosin.

These include:

• medicines to treat erectile dysfunction, like sildenafil (Viagra)
• clarithromycin – an antibiotic often used to treat chest infections and skin infections
• some other blood pressure medicines
• medicines to treat fungal infections
• medicines to treat HIV

Before taking doxazosin, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.

Food and alcohol with doxazosin

You can eat as normal while taking doxazosin, but it's best not to drink alcohol while taking doxazosin as this can raise the risks of side effects.

To find out more about your medicine, you can:

• check the leaflet that comes with it
• search for your medicine leaflet on the electronic medicines compendium website
• speak to a pharmacist or doctor for advice – if you recently started taking it, you can get help with newly prescribed medicines from a pharmacist as part of the New Medicine Service