长效 α1-肾上腺素能受体抑制剂，例如多沙唑嗪 (UK 33274)，经常用于治疗下尿路和良性前列腺增生的症状 [1]。多沙唑嗪可以直接抑制胆固醇的合成，而不需要 LDL 受体。多沙唑嗪可以抑制胆固醇的合成，但细胞可能通过上调 LDL 受体来抵消这种作用。这将增加脂蛋白胆固醇的输入并减少培养基中 LDL 胆固醇的含量 [2]。 12 名患者中有 8 名 (66.7%) 多沙唑嗪单药治疗有效； 12 名患者中有 11 名 (91.7%) 与 β 受体阻滞剂联合治疗是有益的。在整个治疗过程中，平均脉率没有变化。只有三名受试者经历了轻微和暂时的不良影响。服用多沙唑嗪时，尿液和血浆儿茶酚胺水平通常会下降或保持不变[3]。

Absorption, Distribution and Excretion
Doxazosin is rapidly absorbed in the gastrointestinal tract and peak concentrations are achieved within 2-3 hours after administration. The bioavailability is about 60%-70%. The intake of food with doxazosin is not expected to cause clinically significant effects.
In a pharmacokinetic study using a 1 mg IV radiolabeled dose and a 2 mg oral dose, 63% of the ingested doxazosin was found to be excreted in the feces and about 9% of the dose was found to be excreted in the urine. 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.
The volume of distribution of doxazosin is 1.0-1.9 L/kg. In a study of radiolabeled doxazosin administered to pregnant rats, doxazosin was found to cross the placenta.
The clearance of doxazosin is low and ranges from approximately 1-2 ml/min/kg.

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Metabolism / Metabolites
Hepatic metabolism of doxazosin produces inactive O-demethylated and C-hydroxylated metabolites. Metabolism occurs via O-demethylation of the quinazoline nucleus of doxazosin or via hydroxylation of its benzodioxan portion. The enzymes involved in the metabolism of doxazosin include CYP2C19, CYP2D6, CYP2C19, and CYP3A4, which is the primary metabolizing enzyme. Doxazosin itself is considered to be mainly responsible for its pharmacological action, however, some active metabolites have been identified whose pharmacokinetics have not been adequately characterized.

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Biological Half-Life
The terminal elimination half-life of doxazosin has been estimated at 9-12 hours according to some resources. The FDA label indicates the elimination half-life of doxazosin is 22 hours.

Hepatotoxicity
Doxazosin has been associated with a low rate of serum aminotransferase elevations that in controlled trials was no higher than with placebo therapy. These elevations were transient and did not require dose modification. No instances of clinically apparent acute liver injury due to doxazosin have been published in the literature, but reports of cholestatic hepatitis have been received by the sponsor. Among the alpha adrenergic receptor antagonists, the most frequently implicated agent in causing liver injury has been alfuzosin with only single, and not well documented cases linked to other alpha blockers. Thus, acute symptomatic liver injury due to doxazosin is quite rare, and severe hepatotoxicity must be exceeding rare, if it occurs at all.
Likelihood score: E* (unproven but suspected rare cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Limited information indicates that maternal doses of 4 mg daily produce low very levels in milk and would not be expected to cause any adverse effects in breastfed infants.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information in nursing mothers was not found as of the revision date. However, the pharmacologically similar drug prazosin does not affect serum prolactin concentration in patients with hypertension, indicating that doxazosin may not affect prolactin levels. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

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Protein Binding
The plasma protein binding of doxazosin is estimated at 98%.. It has also been shown to be bound to the alpha-1 acid glycoprotein.

[1]. Stereoselective binding of doxazosin enantiomers to plasma proteins from rats, dogs and humans in vitro. Acta Pharmacol Sin, 2013. 34(12): p. 1568-74.

[2]. D'Eletto, R.D. and N.B. Javitt, Effect of doxazosin on cholesterol synthesis in cell culture. J Cardiovasc Pharmacol, 1989. 13 Suppl 2: p. S1-4; discussion S4.

[3]. Miura, Y. and K. Yoshinaga, Doxazosin: a newly developed, selective alpha 1-inhibitor in the management of patients with pheochromocytoma. Am Heart J, 1988. 116(6 Pt 2): p. 1785-9.

Doxazosin is a member of the class of quinazolines that is quinazoline substituted by an amino group at position 4, methoxy groups at positions 6 and 7 and a piperazin-1-yl group at position 2 which in turn is substituted by a 2,3-dihydro-1,4-benzodioxin-2-ylcarbonyl group at position 4. An antihypertensive agent, it is used in the treatment of high blood pressure. It has a role as an antihypertensive agent, an alpha-adrenergic antagonist, an antineoplastic agent, a vasodilator agent and an antihyperplasia drug. It is a member of quinazolines, a N-acylpiperazine, a N-arylpiperazine, a benzodioxine, a monocarboxylic acid amide and an aromatic amine.
Doxazosin is an alpha-1 antagonist used for the treatment of benign prostatic hypertrophy (BPH) symptoms and hypertension. Other members of this drug class include [Prazosin], [Terazosin], [Tamsulosin], and [Alfuzosin]. Because of its long-lasting effects, doxazosin can be administered once a day. It is marketed by Pfizer and was initially approved by the FDA in 1990.
Doxazosin is an alpha-Adrenergic Blocker. The mechanism of action of doxazosin is as an Adrenergic alpha-Antagonist.
Doxazosin is a nonselective alpha-1 adrenergic antagonist (alpha-blocker) used in the therapy of hypertension and benign prostatic hypertrophy. Doxazosin is associated with a low rate of transient serum aminotransferase elevations, but has not been linked to instances of clinically apparent acute liver injury.
Doxazosin is a quinazoline with antihypertensive and antineoplastic properties. Doxazosin is an alpha-adrenergic antagonist that selectively inhibits alpha-1 adrenergic receptors. Blockages of the alpha-1 adrenergic action on the vascular smooth muscles lead to a decrease in vascular resistance and antihypertensive activity. This agent also shows high affinity to alpha-1c adrenoceptor, the predominant functional type in the prostate, which may partially attribute to its effect in treatment of benign prostatic hyperplasia. Furthermore, doxazosin induces apoptosis in prostate cancer cells mediated through inhibition of protein kinase B (PKB)/Akt-signaling death receptor regulatory pathway.
A prazosin-related compound that is a selective alpha-1-adrenergic blocker.
See also: Doxazosin Mesylate (has salt form).

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Drug Indication
Doxazosin is indicated to treat the symptoms of benign prostatic hypertrophy, which may include urinary frequency, urgency, and nocturia, among other symptoms. In addition, doxazosin is indicated alone or in combination with various antihypertensive agents for the management of hypertension. Off-label uses of doxazosin include the treatment of pediatric hypertension and the treatment of ureteric calculi.

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Mechanism of Action
Doxazosin selectively inhibits the postsynaptic alpha-1 receptors on vascular smooth muscle by nonselectively blocking the alpha-1a, alpha-1b, and alpha-1d subtypes. This action on blood vessels decreases systemic peripheral vascular resistance, reducing blood pressure, exerting minimal effects on the heart rate due to its receptor selectivity. Norepinephrine-activated alpha-1 receptors located on the prostate gland and bladder neck normally cause contraction of regional muscular tissue, obstructing urinary flow and contributing to the symptoms of benign prostatic hypertrophy. Alpha-1 antagonism causes smooth muscle relaxation in the prostate and bladder, effectively relieving urinary frequency, urgency, weak urinary stream, and other unpleasant effects of BPH. Recently, doxazosin was found to cause apoptosis of hERG potassium channels in an in vitro setting, possibly contributing to a risk of heart failure with doxazosin use.

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Pharmacodynamics
Doxazosin decreases standing and supine blood pressure and relieves the symptoms of benign prostatic hypertrophy through the inhibition of alpha-1 receptors. 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. Patients must be advised of this risk and to avoid situations in which syncope and dizziness could be hazardous following the ingestion of doxazosin. 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. 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.

C23H25N5O5

451.48

451.185

C, 61.19; H, 5.58; N, 15.51; O, 17.72

74191-85-8

Doxazosin mesylate;77883-43-3;Doxazosin-d8 hydrochloride;1219803-95-8;Doxazosin-d8;1126848-44-9

3157

Typically exists as solid at room temperature

1.371 g/cm3

718ºC at 760 mmHg

289-290°C

388ºC

2.886

175.02

1

9

4

33

678

0

O=C(N1CCN(C2=NC(N)=C3C=C(OC)C(OC)=CC3=N2)CC1)C4OC5=CC=CC=C5OC4

RUZYUOTYCVRMRZ-UHFFFAOYSA-N

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)

[4-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperazin-1-yl]-(2,3-dihydro-1,4-benzodioxin-3-yl)methanone

UK-33274 mesylateUK33274 mesylateUK 33274 mesylateCardura DoxazosinumDoxazosin Doxazosina Doxazosine Alfamedin Aliud Brand of Doxazosin Mesylate Alpharma Brand of Doxazosin Mesylate Almirall Brand of Doxazosin MesylateAlter Brand of Doxazosin Mesylate Apo Doxazosin Apo-Doxazosin

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

注意: 如下所列的是一些常用的体内动物实验溶解配方，主要用于溶解难溶或不溶于水的产品（水溶度<1 mg/mL）。 建议您先取少量样品进行尝试，如该配方可行，再根据实验需求增加样品量。

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注射用配方1: DMSO : Tween 80： Saline = 10 : 5 : 85 (如： 100 μL DMSO → 50 μL Tween 80 → 850 μL Saline)
*生理盐水/Saline的制备：将0.9g氯化钠/NaCl溶解在100 mL ddH ₂ O中，得到澄清溶液。
注射用配方 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL DMSO → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)
注射用配方 3: DMSO : Corn oil = 10 : 90 (如： 100 μL DMSO → 900 μL Corn oil)
示例: 以注射用配方 3 (DMSO : Corn oil = 10 : 90) 为例说明, 如果要配制 1 mL 2.5 mg/mL的工作液, 您可以取 100 μL 25 mg/mL 澄清的 DMSO 储备液，加到 900 μL Corn oil/玉米油中, 混合均匀。

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注射用配方 4: DMSO : 20% SBE-β-CD in Saline = 10 : 90 [如：100 μL DMSO → 900 μL (20% SBE-β-CD in Saline)]
*20% SBE-β-CD in Saline的制备（4°C，储存1周）：将2g SBE-β-CD (磺丁基-β-环糊精) 溶解于10mL生理盐水中，得到澄清溶液。
注射用配方 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (如： 500 μL 2-Hydroxypropyl-β-cyclodextrin (羟丙基环胡精)→ 500 μL Saline)
注射用配方 6: DMSO : PEG300 : Castor oil : Saline = 5 : 10 : 20 : 65 (如： 50 μL DMSO → 100 μL PEG300 → 200 μL Castor oil → 650 μL Saline)
注射用配方 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (如： 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
注射用配方 8: 溶解于Cremophor/Ethanol (50 : 50), 然后用生理盐水稀释。
注射用配方 9: EtOH : Corn oil = 10 : 90 (如： 100 μL EtOH → 900 μL Corn oil)
注射用配方 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL EtOH → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)

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口服配方 1: 悬浮于0.5% CMC Na (羧甲基纤维素钠)
口服配方 2: 悬浮于0.5% Carboxymethyl cellulose (羧甲基纤维素)
示例: 以口服配方 1 (悬浮于 0.5% CMC Na)为例说明, 如果要配制 100 mL 2.5 mg/mL 的工作液, 您可以先取0.5g CMC Na并将其溶解于100mL ddH2O中，得到0.5%CMC-Na澄清溶液；然后将250 mg待测化合物加到100 mL前述 0.5%CMC Na溶液中，得到悬浮液。

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口服配方 3: 溶解于 PEG400 (聚乙二醇400)
口服配方 4: 悬浮于0.2% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 5: 溶解于0.25% Tween 80 and 0.5% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 6: 做成粉末与食物混合

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注意: 以上为较为常见方法，仅供参考， InvivoChem并未独立验证这些配方的准确性。具体溶剂的选择首先应参照文献已报道溶解方法、配方或剂型，对于某些尚未有文献报道溶解方法的化合物，需通过前期实验来确定（建议先取少量样品进行尝试），包括产品的溶解情况、梯度设置、动物的耐受性等。

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。