Doxazosin, the brand name Cardura among others, is a medication used to treat symptoms of benign prostatic hyperplasia (enlarged prostate), hypertension (high blood pressure), and post-traumatic stress disorder (PTSD). For high blood pressure, it is a les + some more technical info; clinically doxazosin is a quinazoline-based selective alpha-1 adrenergic receptor antagonist that produces vasodilation by blocking post-synaptic alpha-1 receptors on vascular smooth muscle, lowering peripheral vascular resistance and reducing bladder outlet obstruction by relaxing prostatic and urethral smooth muscle. It is available in immediate-release and extended-release oral formulations, has substantial oral absorption with Tmax typically 2 to 4 hours for immediate-release formulations, an elimination half-life in most patients of roughly 16 to 22 hours supporting once-daily dosing, and high plasma protein binding. Hepatic metabolism is the principal clearance pathway with involvement of CYP enzymes, and dose adjustments or monitoring may be required in hepatic impairment. Clinically relevant effects include reduction in urinary symptoms in benign prostatic hyperplasia and attenuation of trauma-related nightmares in PTSD studies, while adverse effects are commonly related to vasodilation such as orthostatic hypotension, especially after the first dose or upward titration.
Parent: Alfuzosin/ Doxazosin/ Prazosin/ Terazosin
Parent: Doxazosin
Parent: Doxazosin
Parent: Doxazosin / Doxazosin Mesilate
Parent: Doxazosin
![N-(2-((4-amino-6,7-dimethoxyquinazolin-2-yl)amino)ethyl)-2,3-dihydrobenzo[b][1,4]dioxine-2-carboxamide](https://veeprho.com/wp-content/uploads/2023/03/N-2-4-amino-6-7-dimethoxyquinazolin-2-yl-amino-ethyl-2-3-dihydrobenzo-b-1-4-dioxine-2-carboxamide.png "N-(2-((4-amino-6,7-dimethoxyquinazolin-2-yl)amino)ethyl)-2,3-dihydrobenzo[b][1,4]dioxine-2-carboxamide")
Parent: Doxazosin
![(1-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperidin-4-yl)(2,3-dihydrobenzo[b][1,4]dioxin-2-yl)methanone](https://veeprho.com/wp-content/uploads/2023/03/1-4-amino-6-7-dimethoxyquinazolin-2-yl-piperidin-4-yl-2-3-dihydrobenzo-b-1-4-dioxin-2-yl-methanone.png "(1-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperidin-4-yl)(2,3-dihydrobenzo[b][1,4]dioxin-2-yl)methanone")
Parent: Doxazosin
Parent: Doxazosin
The impurity profile for doxazosin drug substance and finished products typically focuses on related process impurities, oxidation products, N-oxide species, desmethyl variants, positional isomers and residual solvents from synthesis. Typical quality specifications used in industry and pharmacopeial monographs set reporting thresholds and limits such that unidentified individual impurities are generally controlled to not more than 0.10 to 0.20 percent by weight, known specified related compounds are often limited to 0.10 to 0.20 percent each depending on toxicity qualification, and total related substances are commonly capped in the range of 0.5 percent or lower. Residual solvents and elemental impurities follow ICH guidelines with appropriate class limits. Analytical control is achieved by validated HPLC or LC-MS methods with system suitability, identification thresholds, and qualification steps consistent with ICH Q3A and Q3B principles.
Doxazosin is used to relieve urinary obstruction and lower urinary tract symptoms caused by benign prostatic hyperplasia, to lower blood pressure as an antihypertensive agent, and has been studied for reducing trauma-related nightmares and hyperarousal in PTSD. Dose selection and formulation depend on the indication and patient characteristics.
Yes. Doxazosin is a selective alpha-1 adrenergic receptor antagonist that blocks alpha-1 receptors on vascular and genitourinary smooth muscle to produce vasodilation and prostatic/urethral smooth muscle relaxation.
The most common side effects are related to vasodilation and include dizziness, lightheadedness or fainting on standing, fatigue, headache, nasal congestion, peripheral edema, and sometimes gastrointestinal complaints. Sexual side effects such as erectile dysfunction or decreased libido are less common but reported.
Concomitant use with other potent vasodilators or antihypertensives including nitrates, phosphodiesterase type 5 inhibitors, and other alpha-blockers increases the risk of symptomatic hypotension and requires caution or avoidance. Strong CYP3A4 inhibitors or inducers may alter doxazosin exposures and warrant monitoring or dose adjustment. Co-administration with other drugs that substantially lower blood pressure or with sedating agents may increase adverse effects; coordinate management with prescribing clinicians.
