Doxazosin 4mg modified-release tablets
Requires a prescription from a doctor or prescriber
Doxazosin is an alpha-1 antagonist used for the treatment of benign prostatic hypertrophy (BPH) symptoms and hypertension.
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Suspected adverse reactions reported for Doxazosin
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Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
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Suspected adverse reactions reported for Doxazosin
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EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
18 branded products available
Part of the Cardura brand family (generic: Doxazosin)
MHRA licensed products
View all licensed products for Doxazosin on the MHRA register
Cardura XL 4mg tablets
Doxadura XL 4mg tablets
Raporsin XL 4mg tablets
Doxazosin 4mg modified-release tablets
This is the NHS Drug Tariff indicative price used for reimbursement purposes. It may not reflect the price paid by patients or pharmacies.
View full Drug TariffSource: NHS Drug Tariff via NHSBSA. Derived from dm+d VMPP (Virtual Medicinal Product Pack) pricing data. Contains public sector information licensed under the Open Government Licence v3.0.
WHO defined daily dose (DDD)
4 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via NHS dm+d BNF mapping files. Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity based on WHO Anatomical Therapeutic Chemical (ATC) classification and NHS BNF section grouping. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Clinical guidelines and formulary information
British National Formulary
Doxazosin
Source: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
NICE clinical guidance(1)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
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Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & product information
Official product databases and supply status monitoring
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. emc (electronic medicines compendium) is operated by Datapharm Ltd. Shortage information sourced from NHS Specialist Pharmacy Service (SPS), sps.nhs.uk.
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF codes from NHS Business Services Authority (NHSBSA). ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
55 found
Half-life
9-12 hours
Mechanism
Doxazosin selectively inhibits the postsynaptic alpha-1 receptors on vascular sm…
Food interactions
2 warnings
Human targets
4 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
2-3 hours
[A180682]…
Half-life
9-12 hours
[A180646][A180658]…
Protein binding
98%
[A180646][L7282]…
Volume of distribution
1.0-1.9 L/kg
[A180658][A180682]
In a study of radiolabeled doxazosin administered to pregnant rats, doxazosin was found to cross the placenta.
[L7282]…
Metabolism
Elimination
1 mg
Clearance
1-2 ml/min/kg
[A180646][A180682]
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
[L7282]
Off-label uses of doxazosin include the treatment of pediatric hypertension[A180634] and the treatment of ureteric calculi.
[A180637]
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 1381 interactions
The oral LD50 of doxazosin in mice is >1000 mg/kg.
[L7288]
Overdose information
Symptoms of overdose include hypotension, changes in heart rate, and drowsiness.
[A180676]
Administer supportive treatment in case of an overdose with doxazosin. Remove unabsorbed doxazosin from the gastrointestinal tract, correct hypotension, and closely monitor vital signs.
[A180676]
Doxazosin may cause hypotension due to its pharmacological actions. This frequently occurs in the upright position, leading to a feeling of dizziness or lightheadedness. The first dose of doxazosin may lead to such effects, however, subsequent doses may also cause them. The risk of these effects is particularly high when dose adjustments occur or there are long intervals between doxazosin doses. Treatment should be started with the 1 mg dose of doxazosin, followed by slow titration to the appropriate dose.[L7282] Patients must be advised of this risk and to avoid situations in which syncope and dizziness could be hazardous following the ingestion of doxazosin.[L7282] Interestingly doxazosin exerts beneficial effects on plasma lipids. It reduces LDL (low-density lipoprotein) cholesterol and triglyceride levels and increases HDL (high-density lipoprotein) cholesterol levels.[A180649]
A note on priapism risk
In rare cases, doxazosin and other alpha-1 blockers may cause priapism, a painful occurrence of persistent and unrelievable penile erection that can lead to impotence if medical attention is not sought as soon as possible. Patients must be advised of the priapism risk associated with doxazosin and to seek medical attention immediately if it is suspected.[A180670][L7282]
How the body processes this drug — absorption, distribution, metabolism, and elimination
[A180682]
The bioavailability is about 60%-70%.
[A180658][L7282]
The intake of food with doxazosin is not expected to cause clinically significant effects.
[L7282]
[A180646][A180658]
The FDA label indicates the elimination half-life of doxazosin is 22 hours.
[L7282]
[A180646][L7282]
It has also been shown to be bound to the alpha-1 acid glycoprotein.
[A15489]
[A180658][A180682]
In a study of radiolabeled doxazosin administered to pregnant rats, doxazosin was found to cross the placenta.
[L7282]
[L7282]
The enzymes involved in the metabolism of doxazosin include CYP2C19[L7297], CYP2D6, CYP2C19, and CYP3A4, which is the primary metabolizing enzyme.
[L7294]
Doxazosin itself is considered to be mainly responsible for its pharmacological action[A180658], however, some active metabolites have been identified whose pharmacokinetics have not been adequately characterized.
[L7282]
[A180658][L7282]
Traces of radiolabeled unchanged drug were found in the urine and about 5% of the administered drug was found as unchanged drug excreted in the feces.
[L7282]
[A180646][A180682]
Proteins and enzymes this drug interacts with in the body
PMID:32723862
Exhibits faster activation and deactivation kinetics and slow inactivation at membrane potentials positive to 240 mV, resulting in the weakest inward rectification PMID:32723862
Enzymes involved in drug metabolism — important for understanding drug interactions
Proteins that transport this drug across cell membranes
PMID:2897240 PMID:35970996 PMID:8898203 PMID:9038218 PMID:35507548
Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins .
PMID:8898203
Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells PMID:2897240 PMID:35970996 PMID:9038218
PMID:11388889 PMID:11408531 PMID:12439218 PMID:12719534 PMID:15389554 PMID:16263091 PMID:16272756 PMID:16581093 PMID:19536068 PMID:21128598 PMID:23680637 PMID:24961373 PMID:34040533 PMID:9187257 PMID:9260930 PMID:9655880
Functions as a pH- and Na(+)-independent, bidirectional transporter (By similarity). Cation cellular uptake or release is driven by the electrochemical potential (i.e. membrane potential and concentration gradient) and substrate selectivity (By similarity). Hydrophobicity is a major requirement for recognition in polyvalent substrates and inhibitors (By similarity).
Primarily expressed at the basolateral membrane of hepatocytes and proximal tubules and involved in the uptake and disposition of cationic compounds by hepatic and renal clearance from the blood flow (By similarity). Most likely functions as an uptake carrier in enterocytes contributing to the intestinal elimination of organic cations from the systemic circulation .
PMID:16263091
Transports endogenous monoamines such as N-1-methylnicotinamide (NMN), guanidine, histamine, neurotransmitters dopamine, serotonin and adrenaline .
PMID:12439218 PMID:24961373 PMID:35469921 PMID:9260930
Also transports natural polyamines such as spermidine, agmatine and putrescine at low affinity, but relatively high turnover .
PMID:21128598
Involved in the hepatic uptake of vitamin B1/thiamine, hence regulating hepatic lipid and energy metabolism .
PMID:24961373
Mediates the bidirectional transport of acetylcholine (ACh) at the apical membrane of ciliated cell in airway epithelium, thereby playing a role in luminal release of ACh from bronchial epithelium .
PMID:15817714
Transports dopaminergic neuromodulators cyclo(his-pro) and salsolinol with lower efficency .
PMID:17460754
Also capable of transporting non-amine endogenous compounds such as prostaglandin E2 (PGE2) and prostaglandin F2-alpha (PGF2-alpha) .
PMID:11907186
May contribute to the transport of cationic compounds in testes across the blood-testis-barrier (Probable). Also involved in the uptake of xenobiotics tributylmethylammonium (TBuMA), quinidine, N-methyl-quinine (NMQ), N-methyl-quinidine (NMQD) N-(4,4-azo-n-pentyl)-quinuclidine (APQ), azidoprocainamide methoiodide (AMP), N-(4,4-azo-n-pentyl)-21-deoxyajmalinium (APDA) and 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP) PMID:11408531 PMID:15389554 PMID:35469921 PMID:9260930
ATC C02CA04
ATC G04CA55
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
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Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Doxazosin
Additional database identifiers
Drugs Product Database (DPD)
11258
ChemSpider
3045
BindingDB
86731
HUGO Gene Nomenclature Committee (HGNC)
HGNC:277
GenAtlas
ADRA1A
GeneCards
ADRA1A
GenBank Gene Database
D25235
GenBank Protein Database
433201
Guide to Pharmacology
22
UniProt Accession
ADA1A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:280
GenAtlas
ADRA1D
GeneCards
ADRA1D
GenBank Gene Database
M76446
GenBank Protein Database
177807
Guide to Pharmacology
24
UniProt Accession
ADA1D_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:6251
GenAtlas
KCNH2
GeneCards
KCNH2
GenBank Gene Database
U04270
GenBank Protein Database
487738
Guide to Pharmacology
572
UniProt Accession
KCNH2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:18862
GenAtlas
KCNH6
GeneCards
KCNH6
GenBank Gene Database
AF311913
GenBank Protein Database
11878259
Guide to Pharmacology
573
UniProt Accession
KCNH6_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:18863
GenAtlas
KCNH7
GeneCards
KCNH7
GenBank Gene Database
AF032897
GenBank Protein Database
4104136
UniProt Accession
KCNH7_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:278
GenAtlas
ADRA1B
GeneCards
ADRA1B
GenBank Gene Database
M99589
Guide to Pharmacology
23
UniProt Accession
ADA1B_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2637
GenAtlas
CYP3A4
GeneCards
CYP3A4
GenBank Gene Database
M18907
Guide to Pharmacology
1337
UniProt Accession
CP3A4_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2621
GeneCards
CYP2C19
GenBank Gene Database
M61854
GenBank Protein Database
181344
Guide to Pharmacology
1328
UniProt Accession
CP2CJ_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2623
GenAtlas
CYP2C9
GeneCards
CYP2C9
GenBank Gene Database
AY341248
Guide to Pharmacology
1326
UniProt Accession
CP2C9_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2625
GenAtlas
CYP2D6
GeneCards
CYP2D6
GenBank Gene Database
M20403
GenBank Protein Database
181350
Guide to Pharmacology
1329
UniProt Accession
CP2D6_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:40
GenAtlas
ABCB1
GeneCards
ABCB1
GenBank Gene Database
M14758
GenBank Protein Database
307180
Guide to Pharmacology
768
UniProt Accession
MDR1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:10963
GeneCards
SLC22A1
GenBank Gene Database
X98332
GenBank Protein Database
2511670
Guide to Pharmacology
1019
UniProt Accession
S22A1_HUMAN
International reference pricing
Reference pricing from DrugBank. Prices are indicative and may not reflect current UK costs.
Source: DrugBank. Used under CC BY-NC 4.0 academic licence for non-commercial purposes.
DrugBank citations
If you use DrugBank data in your research, please cite the following publications: