地西泮

title: 历史.
content: 地西泮由罗氏公司(Hoffmann–La Roche)开发,在1963年获准使用,它的药效是较早面世的同类药物氯氮䓬(或译甲氨二氮䓬)的大约5倍。地西泮的销量迅即超越氯氮䓬。其他药厂看到地西泮的成功,便开发其它新的苯二氮䓬类药物。  医学界视苯二氮䓬类药物较以往常用的巴比妥盐类药物更好,因为后者的治疗剂量和中毒剂量差距较少(即是稍微过量便容易中毒),且会形成较强的依赖性。过量服用地西泮较不容易引致死亡(不过仍然有人因服用地西泮过量而死亡),但如同时服用其它镇静剂或酒类则会增加危险。
title: 物理特性.
content: 地西泮是白色或黄色结晶状固体,无气味,微苦,微溶或不溶于水。  地西泮可吸附在塑胶上。
title: 药理学.
content: 此类药物作用于体内抑制性神经递质:γ-氨基丁酸(GABA)的一种受体"GABAA受体复合物"(复合物包含GABA受体,苯二氮䓬类药物受体和一个与GABA受体偶联的氯离子通道),而药物与受体的这种作用诱导GABA受体偶联的氯离子通道加强开放,这样会增加氯离子流入胞内的数量,产生超极化而抑制突触后电位,减少中枢某些重要神经元放电,引起中枢抑制。与酒精,阿片类药物同属于神经抑制剂,可用于缓解酒精的戒断反应,长期使用亦可导致依赖。  地西泮的口服半数致死量在小鼠是720毫克/千克,大鼠是1240毫克/公斤。格林布拉特和他的同事在1978年报导,分别服用了500和2000毫克的地西泮,进入中等深度昏迷的两名病人,根据在医院后续的采样,尽管具有高浓度的地西泮及其代谢产物去甲基地西泮,奥沙西泮,替马西泮,分别在48小时内出院而没有任何重要的并发症。
title: 药物动力学.
content: 地西泮可口服、静脉注射、肌肉注射、或以栓剂方式给药。  地西泮在口服后,迅速被身体吸收,药效很快开始,以静脉注射,药效更快。地西泮经肝脏代谢,其代谢物经肾脏排泄,只有极少量的地西泮没有被代谢便排泄。  地西泮脂溶性较高,肌肉注射吸收慢而不规则,也不完全,血浓度不稳定,其峰值血药浓度比口服还低,故临床上一般不宜采用肌肉注射的方法给药。
title: 成瘾性及滥用.
content: 如服用治疗剂量的地西泮达6星期或以上,能产生物质依赖,停药时可出现脱瘾症状。如服用更大剂量,可更快产生物质依赖。  当停药时,剂量应在2至4星期间逐渐减少,以避免脱瘾症状出现。  地西泮是1971年“精神药物公约”所管制的物质之一,在世界各地受严格管制,例如民众需经医生处方取得药物,供应者需保存准确存货记录。法例上,在台湾列为第四级毒品。地西泮在中国大陆列为第二类精神药品,在香港列为第一部危险药物。

Summary: 地西泮(英语:Diazepam),另有中文译名地西畔、戴阿剂盘、安定、苯甲二氮䓬,著名商品名称有烦宁(Valium),化学式CHClNO,属于苯二氮䓬类药物 。地西泮常用于治疗焦虑症、酒精戒断症候群、苯二氮䓬类药物戒断症候群、痉挛、癫痫发作、失眠,和睡眠脚动症。也用于一些外科手术中,促进记忆消失。该药可由口服、直肠塞剂、肌肉注射,以及静脉注射给药。如果经静脉注射给药,药效大约会于1至5分钟起作用,可维持至多一小时。口服的药效会延迟约40分钟才起作用,作用时间大致与静脉注射相同。 地西泮的药效源自于活化γ-氨基丁酸(GABA)的作用,常见副作用包含嗜睡以及运动协调性障碍,严重副作用较少见,包含自杀、呼吸减少,过度使用也可能反而增加癫痫发作的机会。偶尔会造成躁动或兴奋。长期使用可能导致药物耐受性、依赖性,减少药量甚至可能造成戒断症。长期服药期间贸然停药可能会有潜在危险,包括可能维持长达半年的认知障碍。该药不建议在妊娠或哺乳期间服用。

Diazepam: Diazepam, first marketed as Valium, is a medicine of the benzodiazepine family that typically produces a calming effect. It is commonly used to treat a range of conditions, including anxiety, seizures, alcohol withdrawal syndrome, benzodiazepine withdrawal syndrome, muscle spasms, trouble sleeping, and restless legs syndrome. It may also be used to cause memory loss during certain medical procedures. It can be taken by mouth, inserted into the rectum, injected into muscle, injected into a vein or used as a nasal spray. When given into a vein, effects begin in one to five minutes and last up to an hour. By mouth, effects begin after 15 to 60 minutes. Common side effects include sleepiness and trouble with coordination. Serious side effects are rare. They include suicide, decreased breathing, and an increased risk of seizures if used too frequently in those with epilepsy. Occasionally excitement or agitation may occur. Long term use can result in tolerance, dependence, and withdrawal symptoms on dose reduction. Abrupt stopping after long-term use can be potentially dangerous. After stopping, cognitive problems may persist for six months or longer. It is not recommended during pregnancy or breastfeeding. Its mechanism of action is by increasing the effect of the neurotransmitter "gamma"-aminobutyric acid (GABA). Diazepam was patented in 1959 by Hoffmann-La Roche. It has been one of the most frequently prescribed medications in the world since its launch in 1963. In the United States it was the highest selling medication between 1968 and 1982, selling more than two billion tablets in 1978 alone. In 2017, it was the 135th most commonly prescribed medication in the United States, with more than five million prescriptions. In 1985 the patent ended, and there are now more than 500 brands available on the market. It is on the World Health Organization's List of Essential Medicines. The wholesale cost in the developing world is about US$0.01 per dose. In the United States, it is about US$0.40 per dose.