Doxazosin

Doxazosin

Systematic (IUPAC) name
(RS)-2-{4-[(2,3-dihydro-1,4-benzodioxin-2-yl)carbonyl]piperazin-1-yl}-6,7-dimethoxyquinazolin-4-amine
Clinical data
Trade names	Cardura
AHFS/Drugs.com	monograph
MedlinePlus	a693045
Pregnancy cat.	?
Legal status	℞ Prescription only
Routes	oral
Pharmacokinetic data
Bioavailability	65%
Protein binding	98%
Metabolism	Hepatic
Half-life	22 hours
Identifiers
CAS number	74191-85-8
ATC code	C02CA04
PubChem	CID 3157
DrugBank	APRD00474
ChemSpider	3045 Y
UNII	NW1291F1W8 Y
KEGG	D07874 Y
ChEBI	CHEBI:4708 Y
ChEMBL	CHEMBL707 Y
Chemical data
Formula	C23H25N5O5
Mol. mass	451.475 g/mol
SMILES	eMolecules & PubChem
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
Y(what is this?)  (verify)

Doxazosin mesylate, a quinazoline compound sold by Pfizer under the brand names Cardura and Carduran, is an α1a-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.

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 ALLHAT study stopped its arm of the trial looking at alpha blockers, because doxazosin (Cardura) was less effective than a simple diuretic, and because patients on Cardura 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 sophisticated damage-control campaign in early 2000, and sales were largely unaffected, despite the dangers highlighted by the study.

Recent Studies have given new rise to a preference for Doxazosin as a BPH Drug, as it was found to treat erectile dysfunction (ED). The company’s own study did not yield as statistically significant results; however, Doxazosin does show promise for men with BPH and ED.

External links

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