问题 多项选择题

案例摘要:患者,男性,25岁。5年来上腹痛,服药后短时间即缓解。近来因天气转冷,工作劳累又发。上腹灼痛,反酸,疼痛多出现在早上10点、下午4点左右,有时夜间痛醒,进食后缓解。X线钡餐检查:十二指肠溃疡。

抑制胃酸分泌药包括()

A.M胆碱受体阻断药

B.H受体阻断药

C.胶体铋剂

D.质子泵抑制药

E.胃泌素受体阻断药

答案

参考答案:A, B, D, E

解析:1.目前认为,十二指肠溃疡和胃溃疡最多见的共同发病原因是胃酸过高和幽门螺杆菌感染。抑酸药主要有:抗胃泌素药如丙谷胺;抗胆碱能药如普鲁苯辛;H受体拮抗剂如雷尼替丁、法莫替丁、西咪替丁;质子泵抑制剂如奥美拉唑。本题中抑酸药只有H受体拮抗剂雷尼替丁、西咪替丁,但由于患者为年轻男性,而西咪替丁有抗雄激素样作用,应慎用,因此首选雷尼替丁。 2.抑制胃酸分泌药包括:①H受体阻断药有西咪替丁、雷尼替丁、法莫替丁、尼扎替丁等。可抑制各种原因引起的胃酸分泌,主要治疗十二指肠溃疡、胃溃疡,复发率较高,小剂量维持治疗可降低复发率。②M胆碱受体阻断药如哌仑西平、替仑西平等,选择性阻断M受体,抑制胃酸分泌,疗效相当H受体阻断药。同时也抑制胃蛋白酶分泌,对其他腺体、平滑肌、心脏影响小,不良反应轻微。③质子泵抑制药如奥美拉唑。④胃泌素受体阻断药如丙谷胺。 3.幽门螺杆菌产生多种酶及细胞毒素,分解黏液,损伤胃上皮细胞,诱发炎症、溃疡,并影响溃疡的愈合。抗幽门螺杆菌药包括:阿莫西林、甲硝唑、四环素、呋喃唑酮、枸橼酸铋钾等,在体内单一药物疗效差,2~3种药物合用疗效好。根除幽门螺杆菌临床上采取三联疗法:胶体铋剂(如枸橼酸铋)、质子泵抑制剂(如洛赛克)任选一种;克拉霉素、阿莫西林、甲硝唑(呋喃唑酮)抗菌药任选两种。 4.服用质子泵抑制剂后,夜间会有超过1个小时的时间出现胃内pH小于4.0,称为夜间酸突破现象。国外专家研究建议,在应用奥美拉唑的基础上,睡前加用雷尼替丁150mg,以求在不同环节同时抑酸,从而降低夜间酸突破现象的发生率。夜间酸突破现象会带来一些负面影响,主要问题是使十二指肠溃疡难愈,尤其是诱发溃疡出血,并使根除幽门螺杆菌(HP)的药物疗效降低,延长愈合及根治时间,且可能引起病情反复。 5.氯吡格雷是一种抗凝药,用于预防因血块凝结引起的心脏病发作和中风,但氯吡格雷需通过酶CYP2C19转换成活性代谢产物才能产生药理作用。奥美拉唑等许多质子泵抑制剂可抑制药物代谢酶CYP2C19,从而抑制氯吡格雷转换成活性代谢产物使氯吡格雷对血小板的效应降低多达47%。为此2009年FDA发布有关氯吡格雷与奥美拉唑相互作用的安全警告,心脏病发作或中风的高危患者应用氯吡格雷预防血凝块,若同时服用奥美拉唑,药效就会大打折扣。

单项选择题
单项选择题

It sounds like a science fiction, but researchers say it’s a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too.
The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte- literally, "fish killer. " It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding.
Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish’s nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them.
Whether humans are affected by the dinoflagellate’s toxin remains to be seen. Researchers think it’s unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation.
To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack.

Which of the following statements is true

A. Scientists have solved the mystery about the fish killer.
B. More studies need to be made about the fish killer.
C. It is proved that the algae are reducing fish populations.
D. Humans have already been affected by the toxin.