Doxazosin

• Doxazosin is prescribed to treat high blood pressure (hypertension) or enlargement of the prostate in men
• Doxazosin belongs to a family of medications called alpha blockers
• Doxazosin is usually taken once each day
• Doxazosin is sometimes known by its brand names Cardura or Doxadura
• Side effects include dizziness and light-headedness, and you must not drive or operate machinery if either of these side effects occur
• It is important to read the patient leaflet for a full list of side effects and cautions.

When treating hypertension (high blood pressure), doxazosin works by relaxing the blood vessels so that the blood can pass through the vessels more easily. This lowers the blood pressure and reduces the amount of force the heart needs to pump with. 

When used to treat benign prostatic hypertrophy (non-cancerous enlargement of the prostate that commonly occurs as men get older), doxazosin works to relax the muscles near to the bladder and prostate. This relieves the pressure on the urethra so that urine can flow out of the body more easily. This helps to reduce the associated symptoms of BPH including difficulty passing urine, having to get up at night to pass urine, and dribbling of urine after you have finishing peeing.

Doxazosin is a tablet that should be swallowed with some water. It can be taken in the morning or evening, with or without food. It is common to start by taking doxazosin at night, so that if you do get side effects such as dizziness or feeling light-headed, these can wear off overnight.

For hypertension, a common starting dose is 1mg of doxazosin once a day. This may need to be increased up to a maximum of 4mg once a day, depending on your response to treatment and any side effects experienced.

For benign enlargement of the prostate, a common starting dose is 1mg of doxazosin once a day. This may need to be increased up to 2 to 4mg once a day, depending on your response to treatment and any side effects experienced.

Like all medications, doxazosin can have some side effects. The most common side effects include:

• Feeling tired
• Feeling dizzy, light-headed, or faint
• Headache
• Aches and pains
• Swollen feet and ankles
• Dry mouth
• Nausea (feeling sick)
• Palpitations
• Feeling itchy.

These side effects are likely to settle down, but if they persist or become troublesome you should speak to your doctor for further advice.

There is a small increase in the risk of chest and urinary infections. If you think you may have an infection, see your doctor who may need to prescribe antibiotics.

Serious allergic reactions happen very rarely. If you have a severe allergic reaction (anaphylaxis) including breathlessness, lip swelling or tongue swelling, call 999 immediately.

Doxazosin may not be suitable for everyone. You should tell your prescriber if you:

• Have a history of fainting due to low blood pressure
• Have ever felt dizzy or faint, or have fainted, after standing up or after passing urine
• Have bladder stones
• Have chronic or recurrent urinary tract infections
• Have low blood pressure
• Have heart valve disease including aortic or mitral stenosis
• Have heart failure
• Have pulmonary oedema
• Have, or have ever had, a pulmonary embolism (PE or blood clot in the lungs)
• Have, or have ever had, a pericardial effusion
• Are pregnant, trying to conceive, or breastfeeding.

Some medications can interact with doxazosin. You may be advised that doxazosin will not suit you if you already take:

• Sildenafil, tadalafil or vardenafil (medications used to treat erectile dysfunction)
• Some antibiotic, antifungal, and anti-viral medications
• Another medication that lowers blood pressure
• Cimetidine.

You must tell your doctor that you take doxazosin if you are due to undergo cataract surgery.

Because doxazosin may not suit everyone, we will complete a Consultation with you including a health questionnaire. This will ensure that the medication will be suitable for you.

A qualified prescriber will review your current medications, including any herbal remedies or supplements, to ensure that doxazosin will not interact with them. 

Once prescribed, doxazosin will be ordered on your behalf via electronic prescription. Doxazosin will then be conveniently dispatched from one of our partner pharmacies.