消化系统药物课件

1、消化系统药物Digestive System Agents消化系统药物Digestive System AgenCommon gastrointestinal symptoms Dyspepsia胃炎Peptic ulcer disease胃溃疡Diarrhea泄泻Constipation便秘Common gastrointestinal sympto 抗消化性溃疡药 消化性溃疡主要十二指肠溃疡、胃溃疡，其发病系保护与攻击因子失平衡有关。保护因素攻击因子 抗消化性溃疡药 抗消化性溃疡药消化性溃疡主要指发生在胃和十二指肠的慢性溃疡，具有自然缓解和反复发作的特点。临床主要症状：反酸、嗳气、周期性上

2、腹部疼痛。发病机制：损伤胃肠粘膜的攻击因子增强或防御因子减弱所致。抗消化性溃疡药消化系统药物课件Types of UlcersTypeDuodenal Ulcer十二指肠Gastric Ulcer胃LocationFirst part of small intestineStomachPain Upper abdomen, slightly to R of midline Often possible to point to site of pain Dull & more likely to occur when stomach is empty Relieved by food & ant

3、acids Same area but less well localized Often aggravated by food, may be associated with N & V Appetite reduction Persistent & severe symptoms Precipitated by smoking and NSAIDs吸烟，止痛药Types of UlcersTypeDuodenal Ul胃壁细胞受体胆碱受体（M）胃泌素受体组胺受体（H2）激活受体，开放钙通道，最后激活H+,K+-ATP酶，分泌H+到胃内胃酸分泌前列腺素受体 前列腺素E，保护胃粘膜.胃壁细胞受

4、体胆碱受体（M）胃泌素受体组胺受体（H2）激活受体根据胃酸分泌机制：H2-受体拮抗剂H2 blockers质子泵抑制剂proton pump inhibitors中和过量胃酸的抗酸药antacids根据胃酸分泌机制：理想抗酸药应该是作用强、迅速、持久、不吸收、不产气、不引起腹泻或便秘，对粘膜及溃疡面有保护收敛作用。本类药物作用基本相同，主要区别在于吸收程度、作用快慢、持续时间和不良反应。抗酸药 理想抗酸药应该是作用强、迅速、持久、不吸收、不产气、不引起腹抗酸药弱碱性物质，中和胃酸，减轻对胃粘膜的刺激和腐蚀。氢氧化镁：抗酸较强，较快，有轻度致泻作用（Magnesium Hydroxide） 氢氧

5、化铝：抗酸较强，缓慢，可致便秘（Aluminium hydroxide）影响四环素的吸收（形成络合物）。碳酸氢钠：抗酸弱，快而短暂，可吸收，产生CO2。用于酸中毒；碱化血及尿液；很少用于抗胃酸Sodium bicarbonate 一般不单用抗酸药氢氧化铝：抗酸较强，缓慢，可致便秘（Aluminium抗组胺药物组胺的作用 在20世纪40年代，发现 涉及变态反应，损伤和胃分泌的生理调节抗组胺药物有效地减弱组胺的许多反应 抗过敏疾病 (现在把这批抗组胺药叫作H1受体拮抗剂)但不能拮抗胃部组胺对胃酸分泌的促进作用抗组胺药物组胺的作用H1受体和H2受体存在组胺受体的两个亚型H2受体 在胃壁细胞存在 与胃

6、酸分泌有关H1受体和H2受体存在组胺受体的两个亚型H2-receptor antagonistsFour FDA-approved:Cimetidine 西咪替丁 （Tagamet）Ranitidine 雷尼替丁 （Zantac）Famotidine 法莫替丁（Pepcid）H2-receptor antagonistsFour FDTherapeutic effects:Promote the healing of gastric and duodenal ulcers (胃和十二指肠溃疡)Gastroesophageal reflux dz GERD (反流性食道炎)Upper GI bl

7、eed GIB (上消化道出血) May be effective in stress ulcers (应激性溃疡) & peptic esophagitis (消化性食道炎) H2-receptor antagonists Therapeutic effects:H2-receptoH+,K+-ATPase (Proton Pump) inhibitorOmeprazole 奥美拉唑 (Prilosec) Lansoprazole 兰索拉唑 (Prevacid) Pantoprazole 泮托拉唑 并且作用最强、效力长久，选择性高，副作用小质子泵抑制剂Proton pump inhibito

8、rsH+,K+-ATPase (Proton Pump) inhTherapeutic usesGastroesophageal reflux dz GERD (反流性食道炎),有效率达7585。Peptic ulcer（消化性溃疡）,服用16月，溃疡愈合率达97，其它类药物无效用4周，愈合率达90。Infection with H. pylori plus(Hp) (幽门螺杆菌感染),幽门螺旋杆菌83%88转阴。Upper GI bleed GIB (上消化道出血)Therapeutic usesGastroesophageAgents Used in infection of Helico

9、bacter Pylori幽门螺杆菌（helicobacter pylori，HP ）为革兰阴性厌氧菌，在胃十二指肠的粘液层与粘膜细胞之间生长，可产生多种酶及细胞毒素，使粘膜损伤。是慢性胃炎、消化性溃疡和胃腺癌等胃部疾患发生发展中的一个重要致病因子。Agents Used in infection of HeFDA-Approved Treatment Regimens for H.pylori InfectionOmeprazole 20mg b.i.d + Clarithromycin 500mg b.i.d + Amoxicillin 1g b.i.d for 10 daysLansop

10、razole 30mg b.i.d + Clarithromycin 500mg b.i.d + Amoxicillin 1g b.i.d for 10 daysBismuth subsalicylate 525mg q.i.d + Metronidazole 250mg q.i.d + Tetracycline 500mg q.i.d 14 days + H2 receptor antagonist 4 wksFDA-Approved Treatment Regimen电镜下幽门螺杆菌 电镜下幽门螺杆菌 有何副作用？有何困难？有何副作用？有何困难？Lacteol forte乳酸杆菌干燥物，抑

11、制腐败细菌生长、繁殖及防止蛋白质发酵，减少肠内产气，促进消化和止泻作用。临床应用：消化不良、腹胀Digestives 助消化药还有什么其他用途？Lacteol forteDigestives 助消化药还有消化系统药物课件Clinical classification of diarrheaTypeMechanismCausesOsmotic渗透性Unabsorbed soluteLactase deficit, magnesium antacid excessSecretory分泌性Increased secretion of electrolytesE. Coli infection, il

12、eal resection, thyroid cancerExudative渗出性Defective absorption, outpouring of mucus and/or bloodUlcerative colitis, Crohns disease, leukemiaMotility disorder传导功能失调Decreased contact timeIrritable bowel syndrome, diabetic neuropathy见泻止泻？Clinical classification of diaLoperamide洛哌丁胺Loperamide洛哌丁胺可抑制肠道平滑肌

13、的收缩，减少肠蠕动各种原因引起的非感染性急、慢性腹泻的对症治疗Slows intestinal motility, allowing absorption of electrolytes and water through the intestineHelps relieve cramps and decrease stool frequencyFor travelers diarrhea, nonspecific acute diarrhea, or chronic diarrhea associated with inflammatory bowel diseaseSide effects

14、: dizziness, constipationLoperamide洛哌丁胺Loperamide洛哌丁胺Loperamide洛哌丁胺对于伴有肠道感染的腹泻，必须同时应用有效的抗生素治疗。不应用于需要避免抑制肠蠕动的患者，尤其是肠梗阻、胃肠胀气或便秘的患者。腹泻患者常发生水和电解质丧失，应适当补充水和电解质。用药过程中出现便秘或 48小时仍无效者应停药。Loperamide洛哌丁胺对于伴有肠道感染的腹泻，必须LomotilAtropine sulfate 25mcg + diphenoxylate HCl 2.5mg 地芬诺酯+阿托品Dose: 2 tab tds-qds (max: 8 ta

15、b/day)LomotilAtropine sulfate 25mc乙酰胆碱acetylcholine乙酰胆碱acetylcholineDrug treatment for diarrheaKaolinAdsorbentsFor mild nonspecific acute diarrheaAdsorb 吸附everything in the GI tractNegligible systemic absorptionSide effects: constipation, bloating, fullness Others : Charcoal, SmectaDrug treatment fo

16、r diarrheaKao思密达Smecta蒙脱石散剂该药不进入血液循环系统，并连同所固定的攻击因子随消化道自身蠕动排出体外不改变正常的肠蠕动成人及儿童急、慢性腹泻如需服用其它药物，建议与该药间隔一段时间思密达Smecta蒙脱石散剂便秘Constipation Causes:因素Disease tumors, hypothyroidism, diabetic neuropathyDrug narcotic analgesics, aluminium-containing antacids, amitriptylinePsychogenic depression, eating disorder

17、s (anorexia), conscious efforts to withhold stoolLifestyle low-fibre diet, inadequate intake of fluids, avoiding the urge to empty the bowel便秘Constipation Causes:因素Type of laxativesBulk-forming laxatives e.g Fybogel, fibrosine Emollient laxatives e.g Docusate sodiumLubricant laxatives e.g Mineral oi

18、lSaline laxatives e.g Fleet enemaHyper-osmotic laxatives e.g. Lactulose, GlycerinStimulant laxatives e.g Senna, Bisacodyl Type of laxativesBulk-forming Bulk-forming laxatives纤维Considered safest among all laxativesSafe for long term useWorks in 1 3 daysSufficient fluid consumption is required (usuall

19、y a glass)喝足够水Side effects : bloatedness, abdominal discomfortBulk-forming laxatives纤维消化系统药物课件Lubricant laxatives油性Mineral oil coats and softens stoolRecommended for patients who need to avoid straining (hemorrhoid surgery, childbirth).Normally short term use短暂用Can cause pneumonia if it leaks into t

20、he lungsNot recommended for the elderly, stroke victims, and those with swallowing difficultiesThey are prone to aspirate, especially while lying down or at bedtimeLubricant laxatives油性Mineral oHyper-osmotic laxativesLactulose type is a special sugar-like laxativeInduce bowel movements by drawing wa

21、ter into the bowel from surrounding body tissuesThis provides a soft stool mass and increased bowel actionOften used for long-term Hyper-osmotic laxativesLactulo乳果糖 lactulose乳果糖还具有双糖的渗透活性，可使水、电解质保留在肠腔而产生高渗效果，故又是一种渗透性泻药，因为无肠道刺激性，亦可用于治疗慢性功能性便秘。 糖尿病患者慎用，对半乳糖不能耐受者不宜服用？乳果糖 lactulose乳果糖还具有双糖的渗透活性，可使水Stimulant laxativesInduce bowel movements