Alpha-1 blocker
Doxazosin
Brand names: Cardura
Adult dose
Dose: Hypertension: 1mg OD initially; titrate to 2–4mg OD (max 16mg). BPH: 1–8mg OD MR formulation
Route: Oral
Frequency: OD
Clinical pearls
- NICE NG136: 4th-line antihypertensive (resistant HT); avoid as monotherapy first-line (ALLHAT data)
- BAUS / NICE NG97: BPH first-line medical therapy
- Inform ophthalmology pre-cataract surgery (IFIS risk)
Contraindications
- Postural hypotension
- Severe hepatic impairment (immediate-release)
- Hypersensitivity
- Pregnancy/breastfeeding
Side effects
- First-dose hypotension (start at bedtime)
- Dizziness
- Headache
- Oedema
- Nasal congestion
- Priapism (rare)
- Intra-operative floppy iris syndrome (cataract surgery)
Interactions
- Other antihypertensives (additive)
- PDE5 inhibitors (hypotension — separate timing)
- CYP3A4 inhibitors
Monitoring
- BP (sit/stand)
- Symptoms
- IPSS in BPH
Reference: BNF; NICE NG136; NICE NG97; BAUS; https://bnf.nice.org.uk/drugs/doxazosin/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Acute Heart Failure · ESC 2021 Heart Failure Guidelines; NICE NG106
- NSTEMI / Unstable Angina · ESC 2020 NSTEMI Guidelines; NICE NG185
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines