← All medications

Doxazosin

Medication alpha-1 blocker heart & blood pressure
Aka: Cardura
Brands seen in Singapore: Cardura
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
High blood pressure and enlarged-prostate symptoms
When to take
NHS: usually once a day, often for several years
Take with
NHS: with a drink of water · alcohol adds side effects
Pros & cons
Pros
  • SG label: usable as the first blood pressure agent
  • SG label: one drug covers bph and blood pressure
  • NHS: once a day, at the SAMe time every day
Cons
  • NHS: headaches, dizziness and vertigo are common
  • NHS: ankle, foot and leg swelling is common
  • One SG brand only — cardura 2 mg tablets
Sources
  1. HSA — Listing of Registered Therapeutic Products (data.gov.sg d_767279312753558cbf19d48344577084), Forensicclassification column; read from the cached copy at /tmp/hsa_all.json and filtered locally, not re-fetched · read 2026-08-27
    what it says
    “CARDURA TABLET 2 mg SIN05014P | DOXAZOSIN MESYLATE 2.43MG EQV DOXAZOSIN | Prescription Only | C02CA04 — the ONLY doxazosin row in the register”
  2. MOH National Drug Formulary (Singapore) — CARDURA TABLET 2 MG [SIN05014P], product information · read 2026-08-27
    what it says
    “DOXAZOSIN MESYLATE 2.43 MG EQV DOXAZOSIN - 2 MG … Forensic Classification PRESCRIPTION ONLY MEDICINES … Anatomical Therapeutic Chemical (ATC) code C02CA04 … Prescription-only Medicines with Exemptions for Supply without Prescription NA”
  3. MOH National Drug Formulary (Singapore) — CARDURA [SIN05014P], section 4.1 Therapeutic indications · read 2026-08-27
    what it says
    “Doxazosin is indicated for the treatment of hypertension and can be used as the initial agent to control blood pressure in the majority of patients … also indicated for … symptoms associated with benign prostatic hyperplasia (BPH).”
  4. MOH National Drug Formulary (Singapore) — CARDURA [SIN05014P], section 4.2 Posology and method of administration · read 2026-08-27
    what it says
    “The full dosage range of doxazosin is 1 mg to 16 mg daily … The usual dose is 2 mg to 4 mg once daily … up to the maximum recommended dose of 8 mg.”
  5. MOH National Drug Formulary (Singapore) — CARDURA [SIN05014P], section 4.3 Contraindications · read 2026-08-27
    what it says
    “Doxazosin is contraindicated in patients with a known hypersensitivity to quinazolines, doxazosin, or any of the inert ingredients.”
  6. NHS medicines A–Z — Doxazosin, what it is for (page last reviewed 3 August 2026) · read 2026-08-27
    what it says
    “Doxazosin is used to: lower high blood pressure (hypertension) … treat the symptoms of an enlarged prostate, such as problems with peeing. Doxazosin is a type of medicine called an alpha blocker.”
  7. NHS medicines A–Z — Doxazosin, how to take it · read 2026-08-27
    what it says
    “You'll usually need to take it once a day, at the same time every day, with a drink of water … Doxazosin treatment is often long term, and you'll probably need to take it for several years”
  8. NHS medicines A–Z — Doxazosin, side effects · read 2026-08-27
    what it says
    “Common side effects of doxazosin include: headaches, dizziness and feeling like everything around you is spinning (vertigo); swelling, usually in your ankles, feet and legs (oedema); cold-like symptoms … tummy pain; feeling sick (nausea) and being sick (vomiting)”
  9. NHS medicines A–Z — Doxazosin, who can and cannot take it · read 2026-08-27
    what it says
    “you have an enlarged prostate and low blood pressure; you have an enlarged prostate and bladder or kidney problems; you've been told you have orthostatic hypotension … not usually used during pregnancy as not enough is known about its safety.”
  10. NHS medicines A–Z — Doxazosin, taking it with other medicines, food and drink · read 2026-08-27
    what it says
    “medicines to treat erectile dysfunction, like sildenafil (Viagra); clarithromycin … some other blood pressure medicines; medicines to treat fungal infections; medicines to treat HIV … it's best not to drink alcohol while taking doxazosin”
Report a correction View as JSON

Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.