ラニチジン 化学特性,用途語,生産方法
用途
ラニチジン（英: Ranitidine、開発コードAH19065）は、ヒスタミンH2受容体拮抗薬の一つである。壁細胞のH2受容体を遮断することにより胃酸分泌を抑制するため、胃酸分泌抑制薬として使用される。商品名ザンタック。消化性潰瘍、胃食道逆流症、Zollinger–Ellison症候群（英語版）の治療に使用される他、蕁麻疹の治療で有効であるとの報告がある。
効能
消化性潰瘍薬, H2受容体拮抗薬
説明
Ranitidine, a H2-receptor agonist, caused contact
dermatitis within the pharmaceutical industry.
使用
Ranitidine (cas# 66357-35-5) was used as a standard for testing the therapeutic effect of brown propolis extract against aspirin and ethanol- induced gastric ulcers.
適応症
Ranitidine (Zantac) is another H2 receptor antagonist that does not have the
same antiandrogen side effects as cimetidine. Note that both cimetidine and
ranitidine inhibit the cytochrome P-450 microsomal enzyme system.
一般的な説明
Ranitidine, N-[2-[[[5-(dimethylamino)methyl]-2-furanyl]methyl]thiol] ethyl]-N'-methyl-2-nitro-l,1-ethenediamine (Zantac), is a white solid, which inits hydrochloride salt form is highly soluble in water. It is anaminoalkyl furan derivative with pKa values of 2.7 (sidechain) and 8.2 (dimethylamino). Ranitidine is more potentthan cimetidine, but less potent than famotidine. Likeother H2-antagonists, it does not appear to bind to otherreceptors.
Bioavailability of an oral dose of ranitidine is about 50%and is not significantly affected by the presence of food.Some antacids may reduce ranitidine absorption and shouldnot be taken within 1 hour of administration of this drug. Theplasma half-life of the drug is 2 to 3 hours, and it is excretedalong with its metabolites in the urine. Three metabolites, ranitidineN-oxide, ranitidine S-oxide, and desmethyl ranitidine,have been identified. Ranitidine is only a weak inhibitor ofthe hepatic cytochrome isozymes, and recommended doses ofthe drug do not appear to inhibit the metabolism of otherdrugs. However, there have been isolated reports of drug interactions(warfarin, triazolam) that suggest that ranitidinemay affect the bioavailability of certain drugs by someunidentified mechanism, perhaps by pH-dependent effect onabsorption or a change in volume of distribution.
In addition to being available in various dosage forms asthe hydrochloride salt, ranitidine is also available as a bismuthcitrate salt for use with the macrolide antibiotic clarithromycinin treating patients with an active duodenalulcer associated with H. pylori infection. Eradication of H.pylori reduces the risk of duodenal ulcer recurrence.
生物活性
Potent, selective and competitive histamine H 2 receptor antagonist (pA 2 = 6.95-7.2). In vivo, inhibits gastric acid secretion induced by histamine, pentagastrin, bethanecol and food. Also inhibits aspirin-induced gastric lesions.
接触アレルゲン
Ranitidine, an H2-receptor antagonist, can cause contact
dermatitis within the pharmaceutical industry and
in health care workers, or may induce systemic drug
reactions in patients.
ラニチジン 上流と下流の製品情報
原材料
準備製品