About doxazosin
Alpha-1 adrenergic blocker
Used for
- Treats high blood pressure.
- Relieves urinary symptoms from an enlarged prostate.
Usual adult dose
High blood pressure: usually 1 mg once daily initially, adjusted gradually; maximum 16 mg daily. Enlarged prostate: usually 1 mg once daily initially, adjusted gradually; maximum 8 mg daily.
Common side effects
- Dizziness or lightheadedness, especially when standing.
- Low blood pressure or fainting.
- Headache or tiredness.
- Swelling of the legs or ankles.
Important warnings
- The first dose or dose increases can cause sudden low blood pressure and fainting.
- Rise slowly from sitting or lying positions.
- Tell an eye surgeon about doxazosin before cataract surgery.
- Use caution with liver problems or medicines that lower blood pressure.
Pregnancy
Not generally used during pregnancy; safety is not well established.
Breastfeeding
Limited information is available; discuss use with a healthcare professional.
Interactions
- Other blood-pressure-lowering medicines may increase dizziness or fainting.
- Sildenafil, tadalafil, and similar medicines can further lower blood pressure.
- Strong CYP3A4 inhibitors, such as clarithromycin, may increase doxazosin levels.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.