Drugs for Treating GI Disorders

1. Drugs for Treating GI Disorders Chapter 11

2. GI Disorders • Peptic Ulcer and Acid Reflux Disorders • Laxatives and Cathartics • Antidiarrheals • Antiemetics • Vomiting

3. Drugs for Peptic Ulcer and Acid Reflux Disorders • Most of these drugs alter gastric acid and its effects on the mucosa of the upper GI tract • Many promote healing of lesions and prevent recurrence of lesions by decreasing cell destructive effects or increasing cell protective effects

4. Drug Classes • Antacids- Maalox, Mylanta • Histamine-2 receptor antagonists- cimetidine (Tagamet) • Proton pump inhibitors- omeprazole (Prilosec) • Helicobacter pylori (H. pylori) agents- antimicrobials- amoxicillin; bismuth subsalicylate (Pepto Bismol); combinations

5. Drug Selection • Proton pump inhibitors are drugs of first choice in most situations- heal more rapidly and may be combined with other drugs for treatment of H. pylori • H-2 antagonists are now over the counter • Antacids are still used to relieve heartburn and abdominal discomfort

6. Patient Teaching Guidelines • For Gastroesophageal reflux disease (GERD) - elevate head of bed, avoid stomach distention, sit upright for 1 to 2 hrs after eating, minimize acid-producing foods, avoid smoking, lose weight • Take drugs as directed • These drugs may prevent absorption of other drugs taken at the same time • Histamine-2 antagonists may alter the effects of several drugs

7. Lifespan Considerations • Children • Antacids have been approved for use in children- others have not but have been used in smaller doses • Elderly • All these drugs may be used in the elderly • Older adults have less gastric acid, so smaller doses are indicated • Monitor for adverse effects

8. Laxatives and Cathartics • Used to promote bowel elimination, such as in cases of constipation • Laxative implies mild effects • Cathartic implies strong effects

9. Drug Classes • Bulk forming laxatives- methylcellulose (Citrucel) • Surfactant laxatives (stool softeners)- docusate sodium (Colace) • Saline cathartics- milk of magnesia, Fleet enema • Stimulant cathartics- bisacodyl (Dulcolax), castor oil • Lubricant laxatives- mineral oil

10. Indications for Use • Relief of constipation • To prevent straining in patients with cardiovascular disease (CVD), hypertension, stroke (CVA), and rectal conditions such as hemorrhoids • As a bowel prep • To accelerate elimination of potentially toxic substances

11. Patient Teaching Guidelines • Diet, exercise, fluid intake can prevent or treat constipation • Eat foods high in dietary fiber- fruits, vegetables, whole grain cereals and breads • Establish regular bowel habits • Laxative use should be temporary • Take as directed

12. Lifespan Considerations • Children • Glycerin suppositories in younger children • Stool softeners in older children • Don’t use strong stimulant laxatives • Don’t use saline laxatives if under 2 yrs of age • Elderly • Constipation is a common problem • Laxatives may be overused • Strong stimulants should be avoided • Metamucil is drug of choice for use on a regular basis- take with a full glass of liquid

13. Antidiarrheals • Used to treat diarrhea • Drugs may be given to relieve the symptoms or treat the underlying cause of diarrhea

14. Drug Classes • Opiate-related drugs- paregoric; diphenoxylate with atropine (Lomotil) • Antibacterial agents- ciprofloxacin (Cipro); metronidazole (Flagyl) • Miscellaneous drugs- bismuth subsalicylate (Pepto Bismol)

15. Athlete/Patient Teaching Guidelines • Antidiarrheal meds are not always needed • Drink plenty of fluids, avoid spicy foods and fruits and vegetables until diarrhea stops • Good handwashing, proper food storage can prevent diarrhea • Take drugs only as needed and as directed • See health care provider if diarrhea is accompanied by abdominal pain or fever

16. Lifespan Considerations • Children • Appropriate fluid replacement is important in conjunction with medications • Elderly • Diarrhea is less common than constipation • Excessive laxative use may cause diarrhea • Watch for fluid volume deficits • Most drugs can be given- watch for constipation as a complication

17. Antiemetics • Used to prevent or treat nausea and vomiting from various causes • Drugs from many classes are used to treat nausea and vomiting

18. Drug Classes • Phenothiazines- promethazine (Phenergan) • Antihistamines- hydroxyzine (Vistaril) • Prokinetic agent- metoclopramide (Reglan) • 5-HT3 (serotonin) receptor antagonists- dolasetron (Anzemet) • Miscellaneous- scopolamine (Transderm scopolamine)

19. Drug Selection • Depends on cause of nausea and vomiting • 5-HT3 receptor antagonists for chemotherapy or post-op • Anticholinergic and antihistamines for motion sickness • promethazine (Phergan)- antihistaminic, antiemetic, and sedative effects • Metoclopramide (Reglan) when non-obstructive gastric retention

20. Athlete/Patient Teaching Guidelines • Take early- more effective than when nausea and vomiting have begun • Take fluids to prevent dehydration • Lie down and rest to reduce nausea • Be aware of safety precautions of drugs • Take as directed

21. Lifespan Considerations • Children • Use with caution- few studies have been done • May cause more adverse effects than in adults • Elderly • May cause excessive drowsiness • Be aware of dehydration potential • May also cause psychoactive effects