首页 >
吡喹酮
✍ dations ◷ 2025-04-02 18:11:40 #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
- 紫细菌紫细菌指能够通过光合作用产生能量的厌氧变形菌。他们拥有菌绿素a和b、类胡萝卜素等色素,显出紫、红、棕、黄等颜色。光合作用发生在细胞膜上的反应中心,在此,细胞膜向内褶皱成
- 口服口服给药(英语:Oral administration) (per os) 是一种给药途径,通过嘴吞服药物使其在体内发挥作用。许多药物都可以口服给药,因为其往往在全身产生作用,通过血流输送到身体的各个
- 滑膜炎滑膜炎是滑膜(英语:Synovial membrane)发炎的医学术语。滑膜内衬于具有空腔的关节,称为滑液关节。滑膜炎常造成疼痛,尤其是在关节活动时。由于滑液的增生累积,关节通常会肿胀。滑
- 非洲之角非洲之角(索马里语:Geeska Afrika;吉兹语:የአፍሪካ ቀንድ;阿拉伯语:القرن الأفريقي),有时按照其地理位置,又称东北非洲,作为一个半岛,则又称索马里半岛。非洲之角位
- 木聚糖酶木聚糖是植物细胞壁的主要组成成分,它也是可利用的丰富的半纤维素。由于木聚糖的组成上存在着差异,使其被降解为D-木糖就需要一系列的酶参与,在这一过程中起主要作用的是内切木
- 碱性电池碱性电池(英文:Alkaline battery)指使用碱性电解液的电池,一般生活中指称碱性电池,指的是碱性锌锰电池。广义上,碱性电池使用的电极材料包括:锌-二氧化锰、锌-氧化汞、镉-氢氧化镍
- 同位素分离同位素分离通过将某种化学元素的其它类型的同位素去除而达到浓缩某种特殊的同位素的目的。例如,通过同位素分离可以将天然铀分离成浓缩铀和贫铀,这是为核电站以及铀核武器制造
- 16S rRNA16S核糖体RNA(16S ribosomal RNA),简称16S rRNA,是原核生物的核糖体中30S亚基的组成部分。16S rRNA的长度约为1,542 nt。卡尔·乌斯和乔治·福克斯是率先在系统发育中使用的16S
- 疝疝(Hernia),俗称疝气,其最初的意义是“腹痛”,但后世多特指“少腹坠痛”的狐疝,相当于现代医学的“腹股沟疝”。医学上的疝气指的是器官,例如肠子,经由腔室的孔道离开原先的位置。有
- βsup+/supβsup+/sup在核物理学上,双β衰变(又称双重β衰变,英语:double beta decay)是一种放射性衰变,当中在原子核内的两颗质子同时变换成两颗中子,反之亦然。跟单β衰变一样,这个过程能使原子更接近