プラゾシン塩酸塩 化学特性,用途語,生産方法
外観
白色～ほとんど白色粉末～結晶
解説
プラゾシン塩酸塩，プラゾシンエンサンエン，C19H21N5O4·HCl(419.87)．4-アミノ-2-クロロ-6,7-ジメトキシキナゾリンに順次ピペラジン，2-フロイルクロリドを縮合させて合成される．白色の結晶性粉末．分解点約274 ℃．メタノール，エタノールに難溶，水，クロロホルム，ジエチルエーテルに不溶．α-アドレナリン遮断剤．本態性高血圧症，腎性高血圧症，前立腺肥大症に伴う排尿障害に処方される．LD50 2000 mg/kg(雄ラット，経口)．
用途
α1 及びα2B 受容体遮断剤です。
MT3 受容体遮断作用も示します。
用途
α1 受容体遮断剤です。
効能
血圧降下薬, α1アドレナリン受容体拮抗薬
商品名
ミニプレス (ファイザー)
化学的特性
Off-White to Yellow Powder
使用
Prazosin Hydrochloride (Terazosin EP Impurity K) is an antihypertensive. α1-Adrenergic blocker.
一般的な説明
The antihypertensive effectsof prazosin hydrochloride, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-furoyl)piperazine monohydrochloride(Minipress), are caused by peripheral vasodilation as a resultof its blockade of 1-adrenergic receptors. In ligand-bindingstudies, prazosin hydrochloride has 5,000-fold greater affinityfor α1-receptors than for some α2-adrenergic receptors.
生物活性
α 1 and α 2B -adrenoceptor antagonist. Also a potent antagonist at the melatonin MT 3 receptor (K i = 10.2 nM). Also available as part of the α 1 -Adrenoceptor Tocriset™ and Mixed Adrenergic Tocriset™ .
臨床応用
Prazosin hydrochloride is readily absorbed, and plasmaconcentrations reach a peak about 3 hours after administration.Plasma half-life is between 2 and 3 hours. Prazosin hydrochlorideis highly bound to plasma protein; it does notcause adverse reactions, however, with drugs that might bedisplaced from their protein-binding sites (e.g., cardiac glycosides).It may cause severe orthostatic hypertension becauseof its -adrenergic blocking action, which preventsthe reflex venous constriction that is activated when an individualsits up from a prone position.
純化方法
The salt is recrystallised by dissolving it in hot MeOH, adding a small volume of MeOH/HCl (dry MeOH saturated with dry HCl gas) followed by dry Et2O until crystallisation is complete. Dry it in vacuo over solid KOH till the odour of HCl is absent. It has been recrystallised from hot H2O, the crystals are washed with H2O, and the H2O is removed azeotropically with CH2Cl2, and dried in a vacuum. [NMR and IR: Honkanen et al. J Heterocycl Chem 17 797 1980, cf Armarego & Reece Aust J Chem 34 1561 1981.] It is an antihypertensive drug and is an 1-adrenergic antagonist [Brosman et al. Proc Natl Acad Sci USA 82 5915 1985].
プラゾシン塩酸塩 上流と下流の製品情報
原材料
準備製品