Understanding Laxatives and Antidiarrheals: Uses, Types, and Risks

1. Chapter 25 Laxatives and Antidiarrheals

2. Constipation • Passage of feces through the lower GI tract is slow or nonexistent • May be caused by - ignoring the defecation urge - environmental changes - low residue diet - decreased physical activity - emotional stress - eating constipating foods - constipating drugs - misuse of laxatives - low fluid intake

3. Laxatives • Facilitate the passing of fecal material from the colon and rectum • Reasons for use - test preparation - reduce strain of defecation - parasitic infections - poison removal - constipation

4. Laxatives • Use is widespread • Overuse can be an issue especially in the elderly • Occasional constipation may be normal • Laxative dependence can occur • Prolonged use can lead to - fluid and electrolyte loss - malnutrition - liver disease

5. Laxative Classifications • Stimulant • Saline • Bulk-forming • Lubricant • Stool softeners • Suppositories • Lactulose • Enemas

6. Stimulant Laxatives • Action • Chemical irritation • Increase motility of the GI tract • Increase secretion of water into large and small intestine • Example: bisacodyl

7. Saline Laxatives • Increase osmotic pressure within the intestinal tract • Cause more water to enter the intestines • Result in: • Bowel distention, increased peristalsis, and evacuation

8. Saline Laxatives • Contain salt • Unpleasant taste • Systemically absorbed • Result in: • Poor client compliance • Risk for dehydration • Risk for congestive heart failure

9. Bulk-Forming Laxatives • Safest form • Absorbs water to increase bulk • Distends bowel to initiate reflex bowel activity • Not systemically absorbed • High fiber

10. Bulk-Forming Laxatives • Natural or semisynthetic • Examples: psyllium hydrophilic muciloid (Metamucil), methylcellulose (Citrucel), and polycarbophil (Fibercon)

11. Bulk-Forming Laxatives • Must be followed with a large amount of fluid • If chewed or taken in dry powder form, these agents can cause esophageal obstruction and/or fecal impaction.

12. Lubricant Laxatives • Oils lubricate the fecal material and intestinal walls, thereby promoting fecal passage: • Prevent fat-soluble vitamins from being absorbed • Popular lubricant • Mineral oil • Often made from petroleum products • Not digested or absorbed

13. Stool Softeners • Detergent-like drugs: • Permit mixing of fats and fluids with the fecal mass • Stool becomes softer and is passed much easier • Takes several days to work • Example: docusate salts (Colace and Surfak)

14. Suppositories • Usually in a wax base • Administered rectally • Absorbed systemically

15. Suppositories • Available containing stimulant drugs • Glycerin • Absorbs water from tissues, creating more mass • Bisacodyl • Induces peristaltic contraction by direct stimulation of sensory nerves

16. Lactulose Laxatives • Two monosaccharides that are not digested or absorbed • Digested in the colon by bacteria to form acids substances • Acid substances cause water to be drawn into the colon

17. GoLYTELY • Polyethylene glycol (electrolyte solution and salt) • Must consume 4 liters within 3 hours • Causes a large volume of water to be retained in the colon • Acts within one hour • Produces a diarrheal state

18. Enemas • Hyperosmotics • Solution contain salts (e.g., Fleet enema) • Administered rectally and cause a laxative effect by osmotically drawing fluid into the colon to initiate defecation

19. Long-Term Use • Long-term use of laxatives often results in decreased bowel tone and may lead to dependency. • Encourage • A healthy, high-fiber diet • Increased fluid intake

20. Nursing Considerations • Assess bowel patterns • Encourage fluids for patients taking laxatives • The elderly, children, and patients with electrolyte imbalances should not take saline laxatives • Bulk laxatives can take days to be effective

21. Nursing Considerations • Educate patients that laxatives can be habit-forming • Teach patients proper technique for self-administration of suppositories and enemas • Some laxatives should not be used for longer than 1 week • Use in infants and debilitated patients should be directed by their provider

22. Diarrhea • Abnormally frequent passage of watery stools • Failure of the small and large colon to adequately absorb fluid from the intestinal contents • A symptom of an underlying disorder

23. Diarrhea • Patients with chronic or severe acute diarrhea must be diagnosed before treatment • Untreated diarrhea can lead to dehydration and malnutrition • Therapy is aimed at reducing GI motility, remove irritants, or replace normal bacterial flora

24. Adsorbents • Most commonly used • Claylike materials administered in a tablet or liquid suspension form after each loose bowel movement • Bind to the causative bacteria or toxin, and are eliminated through the stool • Little scientific proof that they work • Examples: kaolin-pectin, attapulgite (Kaopectate)

25. Drugs that Reduce GI Motility • Opiate derivatives - reduce propulsive movement of the small intestine and colon - dependence with prolonged use - depression of the CNS

26. Drugs that Reduce GI Motility • Anticholinergic drugs - reduce intestinal motility - potential dangerous side effects – limits usefulness

27. Antidiarrheals • Loperamide HCl (Imodium) • Made from chemicals related to meperidine, a narcotic • Diphenoxylate HCl and atropine sulfate (Lomotil) • Narcotic and anticholinergic drug • Reduces GI motility

28. Anticholinergics • Decrease intestinal muscle tone and peristalsis of GI tract • Result: slows the movement of fecal matter through the GI tract • Example: belladonna alkaloids (Donnatal)

29. Nursing Considerations • Monitor fluid intake and output • Monitor body weight in infants • Monitor for CNS depression • Adsorbents should not be administered with other drugs • Lactobacillus must be refrigerated

30. Nursing considerations • Adults with fever, dehydration, or persistent diarrhea should contact provider • Infants and young children need sooner evaluation

31. Nursing considerations • Patients with glaucoma or enlarged prostates should not take anticholinergic antidiarrheals • Do not use antidiarrheals with patients with acute abdominal pain • Antidiarrheals can cause constipation