• Take your first dose of doxazosin at bedtime. If you feel dizzy, faint, tired or are sweating, lie down until the feeling passes.
  • As your body is getting used to doxazosin you may feel dizzy or light-headed when standing or sitting up quickly - getting up more slowly will help.

About doxazosin

Type of medicine Alpha-blocker
Used for Hypertension (high blood pressure)
Enlargement of the prostate gland in men
Also called Cardozin XL®
Cardura® XL
Colixil® XL
Doxadura® XL
Doxzogen® XL
Larbex® XL
Slocinx® XL
Available as Tablets
Modified release tablets (these release doxazosin slowly throughout the day to give an even effect)

Doxazosin works in high blood pressure by relaxing the blood vessels. This allows blood and oxygen to circulate more easily around the body, lowering blood pressure and reducing the strain on the heart.

Enlargement of the prostate gland can reduce the flow of urine from the bladder and it can lead to other urinary problems. Doxazosin helps to treat these symptoms by relaxing muscles around the bladder and prostate so that urine can be passed more easily.

Before taking doxazosin

Before taking doxazosin make sure your doctor or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have liver problems.
  • If you have heart problems including heart failure.
  • If you have ever had hypotension (low blood pressure) or dizziness when standing up from a sitting or lying position.
  • If you have ever fainted after passing urine.
  • If you have overflow incontinence (you do not feel the urge to urinate), or anuria (your body is not producing any urine), with or without kidney problems.
  • If you have ever had an allergic reaction to this or any other medicine.
  • If you are taking any other medicines, including those available to buy without a prescription, herbal or complementary medicines.

How to take doxazosin

  • Before starting this treatment, read the manufacturer's printed information leaflet from inside the pack.
  • Take this medicine exactly as directed by your doctor.
  • Doxazosin tablets should be taken once daily.
  • If you are taking doxazosin for the first time, take your very first dose at bedtime. Doxazosin can make you faint or feel faint when taken for the first time.
  • If you have been given the modified release tablet, it should be swallowed whole and not chewed.
  • Take these tablets with a small glass of water. They can be taken before or after food.
  • Try to take this medicine at the same time each day to avoid missing any doses.
  • If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, skip the missed dose. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • Doxazosin can cause dizziness particularly when you first start taking it. Make sure your reactions are normal before driving, using machines or doing any other jobs which could be dangerous if you were not fully alert.
  • Before having any kind of surgery, including dental or emergency treatment, tell your doctor, dentist or surgeon you are taking doxazosin.This is particularly important if you are having eye surgery whilst taking doxazosin.
  • If you buy any medicines, check with a pharmacist that they are safe to take with your other medicines.

Can doxazosin cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common side-effects What can I do if I experience this
Dizziness, light-headedness or fainting, especially when getting up from a lying or sitting position Getting up slowly may help. If you begin to feel dizzy, lie down so that you do not faint, then sit for a few moments before standing to prevent the dizziness returning
Headache Ask your pharmacist to recommend a suitable pain-killer. If the headache continues, speak with your doctor
Tiredness, weakness, sleep disturbances If you feel sleepy, don't drive or use machines
Swelling of the feet or lower legs Try sitting with your legs raised on a buffet or stool. If this persists, speak with your doctor
Shortness of breath, cough, runny nose If these side-effects persist, speak with your doctor or pharmacist
Aches and pains Ask your pharmacist to recommend a suitable painkiller
Dry mouth Try chewing sugar-free sweets or gum
Feeling or being sick Eat little and often. Stick to simple, bland foods

How to store doxazosin

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