GASTROINTESTINAL PHARMACOLOGY

2. GASTROINTESTINALPHARMACOLOGY N V D C

4. NAUSEA

6. Motion sickness Viral Bacterial Food intolerance Surgery Pregnancy Pain Shock Drugs Radiation Middle Ear prob. VOMITING

7. ASSESS

8. NONPHARMACOLOGIC treatment

9. OTC tx. Pepto Bismol

10. "I think the CEO went to get the Dramamine !!!

11. ANTIEMETICSantagonist to: • HISTAMINE • SEROTONIN • DOPAMINE • ACETYLCHOLINE

13. PRESCRIPTION ANTIEMETICS • Antihistamines • Anticholinergics • Dopamine antagonists • Benzodiazapines • Serotonin Receptor antagonists • Cannabinoids • Miscellaneous p. 688-9

18. EMETIC

19. ADSORBENT

23. Foods (spicy/spoiled) Fecal impaction Bacteria Toxins Drug reaction Laxative abuse Malabsorption syndrome Stress & anxiety Bowel tumor Inflammatory bowel dz. Diarrhea

25. Diarrhea • Management and treatment directed at: • Diagnosis and treatment of underlying disease • Replacement of lost water and salts • Relief of cramping • Reducing the passage of unformed stools

26. ASSESS

27. Infectious Diarrhea • Usually self limited • Usually no treatment – antibiotics only when clearly indicated • Traveler’s diarrhea usually caused by E.coli • Treatment usually unnecessary – will run its course in 1-2 days • Prophylaxis possible with doxycycline, TMP-SMZ, and other antibiotics

29. ANTIDIARRHEALS • OPIATES / OPIATE-RELATED • SOMATOSTATIN ANALOGUE • ADSORBENTS • MISCELLANEOUS pg. 696

33. LAXATIVES

34. ACTIONS • Ease or stimulate defecation • Soften stool • Hasten fecal passage through intestine • Facilitate evacuation of feces from rectum

35. TERMINOLOGY • LAXATIVE • Production of a soft, formed stool over a period of one or more days • CATHARTICS/CATHARSIS • Prompt evacuation of bowel fluid

37. CONSTIPATION • Determined primarily by stool consistency or degree of hardness • Frequency is of secondary importance • Principal cause: poor diet

39. ROLE OF FIBER • Proper function of bowel highly dependent on dietary fiber • Best source = bran • Can also be obtained from fruits and vegetables • Fiber facilitates colon function by: • Absorbing water, thereby softening feces and increasing mass • Being digested by colonic bacteria, whose subsequent growth increases fecal bulk

40. CAUSES • FECAL IMPACTION • BOWEL OBSTRUCTION • CHRONIC LAXATIVE USE • NEUROLOGIC DISORDERS • IGNORING URGE TO DEFECATE • LACK OF EXERCISE • DRUGS (ANTICHOLINERGICS, NARCOTICS ANTACIDS)

41. INDICATIONS FOR LAXATIVE USE

42. CONTRAINDICATIONS

43. Non-PHARMACOLICtx of CONSTIPATION

44. 4 TYPES • OSMOTICS (saline) 2. stimulants (contact or irritants) 3. Bulk – forming 4. Emollients (stool softeners)

45. OSMOTIC LAXATIVES • Draws water into intestinal lumen causing fecal mass to soften and swell • High doses used to prepare bowel for surgery and diagnostic procedures; rid bowel of ingested poisons • Watery stool in 2-6 hours • Augment with increased fluid intake

46. GLYCERIN • Softens and lubricates feces • Stimulates rectal contraction useful for reestablishing bowel function after chronic laxative abuse • Suppository formulation • Action in 30 minutes

47. LACTULOSE • Reserved for patients who do not respond to bulk forming laxatives • Soft, formed stool in 1-3 days • Cramping and flatulence common • Expensive

49. POLYETHYLENE GLYCOL-ELECTROLYTE SOLUTIONS • Indicated primarily for cleansing bowel prior to diagnostic procedures • Bowel movement approx. 1 hour after beginning treatment • Dosage volume = 4L • 250-300cc every 10 min. for 2-3 hours • Examples: CoLyte, GoLYTELY