Doxazosin

Doxazosin

File:Doxazosin.svg
File:Doxazosin ball-and-stick.png
Systematic (IUPAC) name
(RS)-2-[4-(2,3-Dihydro-1,4-benzodioxine-2-carbonyl)piperazin-1-yl]-6,7-dimethoxyquinazolin-4-amine
Clinical data
Trade names	Cardura
AHFS/Drugs.com	monograph
MedlinePlus	a693045
Legal status	℞ (Prescription only)
Routes of administration	oral
Pharmacokinetic data
Bioavailability	65%
Protein binding	98%
Metabolism	Hepatic
Biological half-life	22 hours
Identifiers
CAS Number	74191-85-8 Y
ATC code	C02CA04 (WHO)
PubChem	CID: 3157
IUPHAR/BPS	7170
DrugBank	DB00590 Y
ChemSpider	3045 Y
UNII	NW1291F1W8 Y
KEGG	D07874 Y
ChEBI	CHEBI:4708 Y
ChEMBL	CHEMBL707 Y
Chemical data
Formula	C23H25N5O5
Molecular mass	451.475 g/mol
SMILES O=C(N3CCN(c2nc1cc(OC)c(OC)cc1c(n2)N)CC3)C4Oc5c(OC4)cccc5
InChI InChI=1S/C23H25N5O5/c1-30-18-11-14-15(12-19(18)31-2)25-23(26-21(14)24)28-9-7-27(8-10-28)22(29)20-13-32-16-5-3-4-6-17(16)33-20/h3-6,11-12,20H,7-10,13H2,1-2H3,(H2,24,25,26) Y Key:RUZYUOTYCVRMRZ-UHFFFAOYSA-N Y
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Doxazosin mesylate, a quinazoline compound sold by Pfizer under the brand names Cardura and Carduran, is an α1-selective alpha blocker used to treat high blood pressure and urinary retention associated with benign prostatic hyperplasia (BPH).

On February 22, 2005, the US FDA approved a sustained release form of doxazosin, to be marketed as Cardura XL.

It is an alpha-1 adrenergic receptor blocker that inhibits the binding of norepinephrine (released from sympathetic nerve terminals) to the alpha-1 receptors on the membrane of vascular smooth muscle cells. The primary effect of this inhibition is relaxed vascular smooth muscle tone (vasodilation), which decreases peripheral vascular resistance, leading to decreased blood pressure.

Doxazosin and similar medications like prazosin have been found to help reduce the intensity of and/or stop posttraumatic stress disorder night terrors and nightmares. The full explanation for this effect is not understood.

In Egypt, tablet formulation sold as Duracin produced by Biopharm group for research and the drug industry, Dosin by Eipico and Doxazocine by Multi-Apex.

Efficacy

In March 2000, the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study stopped its arm of the trial looking at alpha blockers, because doxazosin was less effective than a simple diuretic, and because patients on doxazosin had a 25% higher rate of cardiovascular disease and twice the rate of congestive heart failure as patients on diuretics. Pfizer, aware of the results before publication, launched a marketing campaign in early 2000, and sales were largely unaffected, despite the dangers highlighted by the study.

Doxazosin shows potential for treatment of benign prostatic hyperplasia and erectile dysfunction.

Doxazosin has also shown some efficacy in treating chronic epididymitis.

External links

• Information about Cardura from rxlist.com
• Cardura XL product website, run by Pfizer