Prazosin 500microgram tablets
Requires a prescription from a doctor or prescriber
Prazosin is a drug used to treat hypertension.
Safety information for pregnancy and breastfeeding
Pregnancy
There are no adequate and well-controlled studies determining the safety of prazosin use during pregnancy.
Breastfeeding
This drug is found excreted in small concentrations in human milk.
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
Report a side effect
Submit a Yellow Card report to the MHRA
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.
View Drug Analysis Profile
Suspected adverse reactions reported for Prazosin
Browse all iDAP reports
Interactive Drug Analysis Profiles for all medicines
Report a side effect
Submit a Yellow Card report to the MHRA
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.
View EudraVigilance report
Suspected adverse reactions reported for Prazosin
About EudraVigilance
Learn about EU pharmacovigilance and safety monitoring
EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
4 branded products available
MHRA licensed products
View all licensed products for Prazosin on the MHRA register
Hypovase 500microgram 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)
5 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
Prazosin
Source: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
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
236 found
Half-life
2-3 hours
Mechanism
Alpha-adrenergic receptors are essential for the regulation of blood pressure in humans.
Food interactions
3 warnings
Human targets
7 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
3 hours
Half-life
2-3 hours
Protein binding
97%
[A176657]…
Volume of distribution
0.6 L/kg
[A176657]
Metabolism
Elimination
Clearance
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
Recently, many studies have evaluated the benefits of this drug in controlling the symptoms of post-traumatic stress disorder (PTSD) and associated nightmares.[A176618][A176621][A176624]
Prazosin does not negatively impact lung function, and therefore may be used to manage hypertension in patients who are asthmatic or patients with chronic obstructive lung disease (COPD).
[A176630]
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 878 interactions
Oral LD50 (rat): 1950 mg/kg; Intraperitoneal LD50 (rat): 102 mg/kg MSDS.
Overdose information
Accidental ingestion of at least 50 mg of prazosin by a two-year-old child led to severe drowsiness with depressed reflexes. There was no fall in blood pressure, and the child recovered without complication [FDA label].
Use in pregnancy
There are no adequate and well-controlled studies determining the safety of prazosin use during pregnancy. It is considered a pregnancy category C drug. Prazosin should be used during pregnancy only in cases where the benefit outweighs the possible risk to the mother and fetus [FDA label]. In specific cases where blood pressure control was emergent during pregnancy, prazosin has been used and no effects on the fetus or neonate were reported [FDA label].
Use in nursing
This drug is found excreted in small concentrations in human milk.
This drug should be used with caution when used during nursing [FDA label].
Prazosin inhibits the postsynaptic alpha-1 adrenoceptors. This inhibition blocks the vasoconstricting (narrowing) effect of catecholamines (epinephrine and norepinephrine) on the vessels, leading to peripheral blood vessel dilation. Through blood vessel constriction by adrenergic receptor activation, epinephrine and norepinephrine normally act to increase blood pressure [A176654].
The pharmacodynamic and therapeutic effect of this drug includes is a decrease in blood pressure as well as clinically significant decreases in cardiac output, heart rate, blood flow to the kidney, and glomerular filtration rate. The decrease in blood pressure may occur in both standing and supine positions [FDA label].
Many of the above effects are due to vasodilation of blood vessels caused by prazosin, resulting in decreased peripheral resistance [A176627], [FDA label]. Peripheral resistance refers to the level resistance of the blood vessels to blood that flows through them. As the blood vessels constrict (narrow), the resistance increases and as they dilate (widen), and peripheral resistance decreases, lowering blood pressure [A176747][L5831].
Effects on sleep disturbance related to post-traumatic stress disorder (PTSD)
Some studies have suggested that this drug improves sleep in patients suffering from insomnia related to nightmares and post-traumatic stress disorder, caused by hyperarousal [A176621][A176624]. This effect likely occurs through the inhibition of adrenergic stimulation found in states of hyperarousal [A176738].
How the body processes this drug — absorption, distribution, metabolism, and elimination
[A176657]
[A176657]
Prazosin is thought to be mostly (about 80-90%) bound to albumin .
[A11794]
[A176657]
[A176627][A176663]
[A176630]
Proteins and enzymes this drug interacts with in the body
PMID:10219239 PMID:10753933 PMID:10790218 PMID:10837251 PMID:11997281 PMID:12063277 PMID:18559421 PMID:22314138 PMID:22359612 PMID:26363003 PMID:27916661 PMID:9230439 PMID:9351446 PMID:9765245
Channel properties are modulated by cAMP and subunit assembly .
PMID:10837251
Characterized by unusual gating kinetics by producing relatively small outward currents during membrane depolarization and large inward currents during subsequent repolarization which reflect a rapid inactivation during depolarization and quick recovery from inactivation but slow deactivation (closing) during repolarization .
PMID:10219239 PMID:10753933 PMID:10790218 PMID:10837251 PMID:11997281 PMID:12063277 PMID:18559421 PMID:22314138 PMID:22359612 PMID:26363003 PMID:27916661 PMID:9230439 PMID:9351446 PMID:9765245
Forms a stable complex with KCNE1 or KCNE2, and that this heteromultimerization regulates inward rectifier potassium channel activity PMID:10219239 PMID:9230439
Proteins that transport this drug across cell membranes
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
PMID:10196521 PMID:10966924 PMID:12538837 PMID:17460754 PMID:20858707
Cation cellular uptake or release is driven by the electrochemical potential, i.e. membrane potential and concentration gradient .
PMID:10966924
Functions as a Na(+)- and Cl(-)-independent, bidirectional uniporter .
PMID:12538837
Implicated in monoamine neurotransmitters uptake such as dopamine, adrenaline/epinephrine, noradrenaline/norepinephrine, histamine, serotonin and tyramine, thereby supporting a role in homeostatic regulation of aminergic neurotransmission in the brain .
PMID:10196521 PMID:16581093 PMID:20858707
Transports dopaminergic neuromodulators cyclo(his-pro) and salsolinol with low efficiency .
PMID:17460754
May be involved in the uptake and disposition of cationic compounds by renal clearance from the blood flow .
PMID:10966924
May contribute to regulate the transport of cationic compounds in testis across the blood-testis-barrier (Probable). Mediates the transport of polyamine spermidine and putrescine (By similarity). Mediates the bidirectional transport of polyamine agmatine .
PMID:12538837
Also transports guanidine .
PMID:10966924
May also mediate intracellular transport of organic cations, thereby playing a role in amine metabolism and intracellular signaling (By similarity)
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:11306452 PMID:12958161 PMID:19506252 PMID:20705604 PMID:28554189 PMID:30405239 PMID:31003562
Involved in porphyrin homeostasis, mediating the export of protoporphyrin IX (PPIX) from both mitochondria to cytosol and cytosol to extracellular space, it also functions in the cellular export of heme .
PMID:20705604 PMID:23189181
Also mediates the efflux of sphingosine-1-P from cells .
PMID:20110355
Acts as a urate exporter functioning in both renal and extrarenal urate excretion .
PMID:19506252 PMID:20368174 PMID:22132962 PMID:31003562 PMID:36749388
In kidney, it also functions as a physiological exporter of the uremic toxin indoxyl sulfate (By similarity). Also involved in the excretion of steroids like estrone 3-sulfate/E1S, 3beta-sulfooxy-androst-5-en-17-one/DHEAS, and other sulfate conjugates .
PMID:12682043 PMID:28554189 PMID:30405239
Mediates the secretion of the riboflavin and biotin vitamins into milk (By similarity). Extrudes pheophorbide a, a phototoxic porphyrin catabolite of chlorophyll, reducing its bioavailability (By similarity).
Plays an important role in the exclusion of xenobiotics from the brain (Probable). It confers to cells a resistance to multiple drugs and other xenobiotics including mitoxantrone, pheophorbide, camptothecin, methotrexate, azidothymidine, and the anthracyclines daunorubicin and doxorubicin, through the control of their efflux .
PMID:11306452 PMID:12477054 PMID:15670731 PMID:18056989 PMID:31254042
In placenta, it limits the penetration of drugs from the maternal plasma into the fetus (By similarity). May play a role in early stem cell self-renewal by blocking differentiation (By similarity).
In inflammatory macrophages, exports itaconate from the cytosol to the extracellular compartment and limits the activation of TFEB-dependent lysosome biogenesis involved in antibacterial innate immune response
Proteins that carry this drug through the body
Appears to function in modulating the activity of the immune system during the acute-phase reaction
ATC C02LE01
ATC C02CA01
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)
Prazosin
Additional database identifiers
Drugs Product Database (DPD)
11108
Drugs Product Database (DPD)
2193
ChemSpider
4724
BindingDB
29568
PDB
XRA
Guide to Pharmacology
503
ZINC
ZINC000095616601
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:278
GenAtlas
ADRA1B
GeneCards
ADRA1B
GenBank Gene Database
M99589
Guide to Pharmacology
23
UniProt Accession
ADA1B_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:281
GenAtlas
ADRA2A
GeneCards
ADRA2A
GenBank Gene Database
M23533
GenBank Protein Database
178196
Guide to Pharmacology
25
UniProt Accession
ADA2A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:282
GenAtlas
ADRA2B
GeneCards
ADRA2B
GenBank Gene Database
M34041
GenBank Protein Database
178198
Guide to Pharmacology
26
UniProt Accession
ADA2B_HUMAN
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:278
GenAtlas
ADRA1B
GeneCards
ADRA1B
GenBank Gene Database
M99589
Guide to Pharmacology
23
UniProt Accession
ADA1B_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:8498
GenAtlas
ORM1
GeneCards
ORM1
GenBank Gene Database
X02544
GenBank Protein Database
757907
UniProt Accession
A1AG1_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
HUGO Gene Nomenclature Committee (HGNC)
HGNC:10967
GeneCards
SLC22A3
GenBank Gene Database
AJ001417
GenBank Protein Database
3581982
Guide to Pharmacology
1021
UniProt Accession
S22A3_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:74
GenAtlas
ABCG2
GeneCards
ABCG2
GenBank Gene Database
AF103796
GenBank Protein Database
4185796
Guide to Pharmacology
792
UniProt Accession
ABCG2_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: