Pharmacology of drugs affecting GIT

1. Pharmacologyof drugs affecting GIT

2. Peptic Ulcer Disease • Imbalance between mucosal defensive factors and aggressive factors • Major defensive – mucus and bicarbonate • Major aggressive – gastric acid, H. pylori, nonsteroidal anti-inflammatory drugs, pepsin

4. Defensive factors • Prevent the stomach and duodenum from being harmed (self-digestion). • Mucus – continually secreted, protective effect • Bicarb – secreted from endothelial cells, neutralized hydrogen ions • Blood flow – good blood flow helps to maintain mucosal integrity • Prostaglandins – stimulate secretion of bicarb and mucus and help promote blood flow, suppress secretion of gastric acid

5. Aggressive factors • Helicobacter pylori – gram negative bacteria, can live in stomach and duodenum • May breakdown mucus layer, inflammatory response to presence of the bacteria may breakdown defenses, also produces urease – forms CO2 and ammonia which are toxic to mucosa

7. PepsinSmoking • NSAIDS – inhibit the production of prostaglandins • Decrease blood flow, decrease mucus production and bicarb synthesis, promote gastric acid secretion • Gastric Acid – also needs to be present for ulcer to form – activates pepsin and injures mucosa

8. Nondrug therapy • Diet – change in eating pattern, 5-6 small meals a day • Smoking cessation, NSAID and ASA should be avoided whenever possible, avoid alcohol

9. Antibacterial drugs • Combinations must be used • Bismuth – disrupts cell wall of H. pylori, pepto-bismol • Clarithromycin – inhibits protein synthesis • Amoxicillin – disrupts cell wall, good when given with omeprazole • Tetracyclin – inhibits protein synthesis • Metronidazole – resistance,

10. Histamine 2-receptor antagonists • Suppress secretion of gastric acid (activation of H2 receptors promotes secretion of gastric acid) • Cimetidine - first available, oral, IV, IM • May take up to twelve weeks for ulcer to be healed • Therapeutic uses – ulcers, GERD, Zollinger-ellison syndrome, aspiration pneumonitis, heartburn, indigestion

13. Proton Pump Inhibitors • Suppress secretion of gastric acid • Omeprazole – prilosec – prodrug that converts to active form in parietal cells of stomach – inhibits enzyme that generates gastric acid • Ulcers, GERD, Zollinger-Ellison syndrome • May contribute to development of gastric tumors?

15. Sucralfate • Creates a protective barrier against acid and pepsin • Form sticky gel that coats ulcer portion • Given every 6 hours • Very few side effects – minimal systemic absorption

16. misoprostol • Cytotec – prevention of gastric ulcers caused by long-term NSAID therapy • Replacement for endogenous prostaglandins

17. Antacids • Peptic ulcers and GERD • Neutralize acid • Dosing – 7 times per day

18. Almagel Combined drug which contains gel of aluminum hydroxide, magnesium oxide and D-sorbit 170 ml bottles

19. Schemes of combined treatment of gastric ulcer • De-nol + amoxycillin • De-nol + metronidazole • Omeprazole + amoxycillin + clarythromycin • De-nol + clarythromycin + metronidazole • De-nol + controlok + amoxycilin + clarythromycin

20. Laxatives • Laxative effect – production of a soft formed stool over a period of 1 or more days • Catharsis – prompt, fluid evacuation of the bowel, more intense • Function of the colon – water and electrolyte absorption • Bowel evacuation – individual • Dietary fiber

21. Indications for laxative use • Pain associated with bowel movements • To decrease amount of strain under certain conditions • Evacuate bowel prior to procedures or examinations • Remove poisons • To relieve constipation caused by pregnancy or drugs

22. Just because laxatives are available without a prescription doesn't mean that they're without risk. Warning: Use of stimulant laxatives over a long period may lead to dependence and might permanently damage intestine and colon

23. Classifications • I – osmotic (high doses) • II – osmotic (low doses), stimulant except castor oil – most frequently abused • III – bulk-forming, surfactant

24. Bulk-forming • Identical to fiber – soften fecal mass, increasing bulk • Temporary treatment of constipation, preferred for patients with inflammatory bowel diseases • May help with diarrhea

25. Adverse reactions • Not absorbed – no systemic effects • Must take with sufficient water • Intestinal, esophageal obstruction • Metamucil, citrucel

26. Surfactant laxatives • Bisacodyl, castor oil • Stimulate intestinal motility • Increase water and electrolytes in intestinal lumen • Produce stool within 6-12 hours

27. Bisakodil

28. Guttalax

29. Miscellaneous laxatives • Mineral oil • Lactulose • Glycerin suppository • Polyethylene glycol-electrolyte solutions

30. Laxative abuse • Most common cause of constipation • Teaching

31. Stigma of corn Common immortelle Choleretics of plant origin Dog-rose

32. Tocopherole acetate (Tocopheroli acetas) Vitamin E is produced in many forms: 5 %, 10 % and 30 % oil solution in 10, 20 and 50 ml bottles; elastic capsules with 0,1 and 0,2 ml of 50 % solution in oil; ampoules with 1 ml of 5 %, 10 % and 30 % oil solutions.

33. CarsilLegalon

34. Mechanism of action of legalon

35. Essentiale Is produced in 5 ml ampoules and in capsules

36. Lipostabil

37. Pancreatin (Panсreatinum) Is produced in 0,25 gand 0,5 g dragee (tablets).

38. Panzynorm forte

39. Festal, Enzistal, Mezym-forte

40. No-spa, nicospan

41. Baralgin

42. Bil-berriesSt. John’s wort

43. Pepper mintChamomile