吡喹酮

✍ dations ◷ 2025-09-15 15:55:51 #吡喹酮
吡喹酮(英语:Praziquantel,或英语:Biltricide)为一种用于人类及动物的驱虫药,专门治疗绦虫及吸虫。对于血吸虫、中华肝吸虫、广节裂头绦虫(英语:Diphyllobothrium latum)特别有效,吡喹酮为世界卫生组织基本药物标准清单上的药物,为世界上对于基本公共卫生最重要的药物之一。1970年代由拜耳公司的药学部研发成功。吡喹酮可以用于治疗人类、哺乳类,以及鱼类的寄生虫病。包含肠胃道或是外部的感染,以下为其适用疾病:The majority of side effects develop due to the release of the contents of the parasites as they are killed and the consequent host immune reaction. The heavier the parasite burden, the heavier and more frequent the side effects normally are.The antibiotic rifampicin decreases plasma concentrations of praziquantel.Carbamazepine and phenytoin are reported to reduce the bioavailability of praziquantel.Chloroquine reduces the bioavailability of praziquantel.The drug cimetidine heightens praziquantel bioavailability.The mode of action is not exactly known at present, but experimental evidence indicates praziquantel increases the permeability of the membranes of schistosome cells towards calcium ions. The drug thereby induces contraction of the parasites, resulting in paralysis in the contracted state. The dying parasites are dislodged from their site of action in the host organism and may enter systemic circulation or may be destroyed by host immune reaction (phagocytosis). Additional mechanisms including focal disintegrations and disturbances of oviposition (laying of eggs) are seen in other types of sensitive parasites.Another hypothesis concerning the mechanism of action of praziquantel has been recently reported. The drug seems to interfere with adenosine uptake in cultured worms. This effect may have therapeutical relevance given that the schistosome, as the Taenia(英语:Taenia (genus)) and the Echinococcus(英语:Echinococcus) (other praziquantel-sensitive parasites), is unable to synthesize purines such as adenosine de novo.Bayer's Animal Health Division website states, "Praziquantel is active against cestodes (tapeworms). Praziquantel is absorbed, metabolized in the liver, and excreted in the bile. Upon entering the digestive tract from the bile, cestocidal activity is exhibited. Following exposure to praziquantel, the tapeworm loses its ability to resist digestion by the mammalian host. Because of this, whole tapeworms, including the scolices (plural of "scolex"), are very rarely passed after administration of praziquantel. In many instances, only disintegrated and partially digested pieces of tapeworms will be seen in the stool. The majority of tapeworms are digested and are not found in the feces."Praziquantel is administered as a racemate, but only the (R)-enantiomer is biologically active; the enantiomers may be separated using a resolution of an amine obtained from praziquantel.Praziquantel is well absorbed (about 80%) from the gastrointestinal tract. However, due to extensive first-pass metabolism, only a relatively small amount enters systemic circulation. Praziquantel has a serum half-life of 0.8 to 1.5 hours in adults with normal renal and liver function. Metabolites have a half-life of 4 to 5 hours. In patients with significantly impaired liver function (Child Pugh classes B ll///d C), the serum half-life is increased to 3 to 8 hours. Praziquantel and its metabolites are mainly excreted renally; within 24 hours after a single oral dose, 70 to 80% is found in urine, but less than 0.1% as the unchanged drug. Praziquantel is metabolized through the cytochrome P450 pathway via CYP3A4. Agents that induce or inhibit(英语:Enzyme induction and inhibition) CYP3A4 such as phenytoin, rifampin, and azole antifungals will affect the metabolism of praziquantel.Praziquantel has a particularly dramatic effect on patients with schistosomiasis. Studies of those treated have shown that within six months of receiving a dose of praziquantel, up to 90% of the damage done to internal organs due to schistosomiasis infection can be reversed.Praziquantel was developed in the laboratories for parasitological research of Bayer AG and Merck KGaA in Germany (Elberfeld and Darmstadt) in the mid 1970s.吡喹酮名列世界卫生组织基本药物标准清单之中, 是世界上对于基本公共卫生最重要的药物之一。在英国,吡喹酮并未获准在人体上使用。但在必要时可以根据在患者实名的情况下进口。在英国吡喹酮可以作为兽用驱虫药销售。在美国,吡喹酮被FDA批准用于血吸虫病及肝吸虫病的治疗,尽管它对其他种类的感染也有效。Template:Anthelmintics

相关

  • 结晶性关节病变结晶性关节病变是一种关节疾病(关节变病),特征是微小晶体沉积在一个或多个关节中。应用偏光显微镜(英语:Polarized light microscopy)和其他晶体学技术协助鉴定各种不同的微晶,包括
  • 菌株分型(strain)是生物学分类使用的概念。指病毒的毒株。例如,不同的流感毒株的感染性不同。细菌或真菌的菌株。是具有不同基因型并能稳定遗传的亚型。植物学与农学的品系,指源自共
  • 头孢卡品头孢卡品(其国际非专利药品名称为“Cefcapene”)是一种第三代头孢菌素。该抗生素常以盐酸头孢卡品酯的形式生产。羧基青霉素:羧苄西林(卡茚西林) · 替卡西林 · 替莫西林
  • 手指手指是人或一些灵长类动物(例如猿)的手上的指头。人的手指虽然非常灵活,但也非常纤细,原因是因为活动手指的肌肉不位于手指内,而位于下臂,这些肌肉通过长的腱来指导手指的运动。有
  • 丹贝丹贝(tempeh)是一种发源于印尼爪哇的发酵食品,又名天培、天贝等。传统丹贝是接种根霉属(Rhizopus spp.)真菌至煮过的脱皮大豆,再以香蕉叶包覆接种过的大豆,经过一至两天发酵,所得到
  • 血浆蛋白结合大多数药物可以与血浆中的蛋白质(如人血清白蛋白、脂蛋白、糖蛋白和α, β, γ 球蛋白)发生不同程度的结合。弱酸性药物主要与白蛋白结合,弱碱性药物除了与白蛋白结合外,还常
  • 米高庄逊迈克尔·约翰逊 或译 米高·庄臣、麦可·强森(Michael Johnson),可指下列人物:
  • 联合国人口基金会联合国人口基金(英语:United Nations Population Fund,简称UNFPA)是联合国一个专门机构,其使命是促进所有人健康生活和平等机会的权利。作为一个志愿性的基金机构,联合国人口基金
  • 吸收剂量吸收剂量(Absorbed dose)是借由辐射方式传到单位质量物质的能量。符号为D,定义为D=dE/dM,其SI单位是戈雷(gray,缩写为Gy),一焦耳的辐射能量被一千克的质量吸收为一戈雷,1Gy=1J/kg。当
  • 医用微生物及免疫学人体解剖学 - 人体生理学 组织学 - 胚胎学 人体寄生虫学 - 免疫学 病理学 - 病理生理学 细胞学 - 营养学 流行病学 - 药理学 - 毒理学免疫学(英语:Immunology)是生物医学的一