Doxazosin at a glance
Medicine class
Selective alpha-1-adrenoceptor blocker.
Licensed uses
High blood pressure and urinary symptoms or obstruction associated with benign prostate enlargement.
Food
Tablets may be taken with or without food.
Dizziness
Dizziness or light-headedness can occur. Sit or lie down until it passes and do not drive while affected.
What is Doxazosin used for?
Selected UK products are licensed for:
Essential hypertension (high blood pressure).
Urinary obstruction and symptoms associated with benign prostatic hyperplasia, such as difficulty passing urine.
How does Doxazosin work?
Doxazosin blocks alpha-1 receptors. This widens blood vessels and relaxes muscle in the prostate and bladder neck, lowering blood pressure and reducing resistance to urine flow. It does not shrink the prostate.
Doxazosin preparations and strengths
Modified-release tablet
Route: Oral
Strengths: 4 mg
Tablet
Route: Oral
Strengths: 1 mg, 2 mg, 4 mg, 8 mg
How to take Doxazosin
Follow the dispensing label and swallow the tablet with water, with or without food. Doxadura XL must be swallowed whole and not chewed, divided or crushed. The selected standard-release tablet may be divided into equal halves when instructed.
Check the packet because standard-release and prolonged-release tablets are handled differently.
If dizzy, sit or lie down and avoid driving, cycling or machinery until fully recovered.
Alcohol can worsen dizziness and light-headedness.
Doxazosin side effects
Common or expected effects
- Dizziness, headache, sleepiness or vertigo
- Low blood pressure, particularly on standing
- Swollen ankles, feet or legs
- Nausea, indigestion, dry mouth or abdominal discomfort
- Cold-like or flu-like symptoms
- Palpitations or a faster heartbeat
- Back pain or muscle pain
- Urinary tract infection or urinary incontinence
Get urgent medical advice
- Severe allergic reaction
- Fainting or severe symptomatic low blood pressure
- Chest pain or symptoms of a heart attack
- Facial weakness, arm weakness or speech difficulty suggesting a stroke
- A painful erection that does not go away
- Yellow skin or eyes, unusual bruising or unexplained bleeding
Doxazosin in pregnancy
Doxazosin is not usually used during pregnancy because human safety information is limited. For hypertension, it should be considered only when the expected benefit outweighs the potential risk. Discuss pregnancy or plans for pregnancy with the prescriber.
Doxazosin while breastfeeding
Product advice differs. The selected standard-tablet information reports very low transfer into milk but limited human evidence and requires an individual benefit–risk decision. Doxadura XL is contraindicated during breastfeeding when used for hypertension. Confirm the exact product and indication with the prescriber or pharmacist.
Doxazosin interactions
Check new prescription, pharmacy and non-prescription medicines with a pharmacist or prescriber.
PDE-5 inhibitors, including sildenafil, tadalafil and vardenafil
The combination can cause low blood pressure, dizziness or fainting.
Other alpha blockers and blood-pressure-lowering medicines
Blood-pressure reduction may be increased, causing dizziness, weakness or fainting.
Common questions about Doxazosin
Answers are fully visible for fast scanning and source review.
Is doxazosin mesilate the same medicine as doxazosin?
Doxazosin mesilate is the salt used in the tablet. Product information commonly states the amount equivalent to doxazosin, the active medicine.
Does doxazosin shrink an enlarged prostate?
No. It relaxes muscle around the prostate and bladder outlet but does not reduce prostate size.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.