1. Gastrointestinal Medications
Chapter 18
Gastrointestinal Medications

2. Chapter 18
Lesson 18.1

3. Learning Objectives
Identify common uses for antacids and histamine H2-receptor antagonists
Compare and contrast the actions of anticholinergic and antispasmodic medications on the gastrointestinal (GI) tract
Compare the actions and adverse reactions of the five major classifications of laxatives

4. Learning Objectives (cont.)
Identify indications for the use of at least two common antidiarrheals, antiflatulents, digestive enzymes, and emetics
Describe indications for disulfiram use and what is meant by "disulfiram reaction"

5. Overview
Three major types of GI medications: restore and maintain the lining of the GI tract; decrease acidity and motility; exert laxative action on the colon
Miscellaneous medications: antiflatulants, digestive enzymes, emetics, and medications to treat gallstones and alcoholism
What is a common OTC drug used in the treatment of GI disorders?
Why would an emetic be ordered?
If a patient has undergone a gastric bypass procedure, which GI medication may be prescribed?
Laxatives work in several ways. They promote bowel emptying by increasing intestinal bulk, lubricating intestinal walls, softening the fecal mass, increasing peristalsis through local tissue irritation, or by direct action on the intestine.

6. Digestive System Functions Structures Protective factors
Digestion variables
What are the three functions of the digestive system?
How does the amount of blood flow to the digestive tract affect the body’s ability to absorb medications?
What is the other name for the digestive tract?
What role does age play in the normal digestive process?

7. Digestive System

8. Antacids, H2-Receptor Antagonists, Proton Pump Inhibitors
Stomach lining and acid production
External factors that contribute to ulcer formation
Protective medications
Table 18-1
What clinical factors may play a role in increased acid production in the stomach?
Why would a GI-protective drug be prescribed in combination with NSAIDs?
Drug treatment includes the use of antacids, H2-receptor antagonists, and proton pump inhibitors

9. Antacids, H2-Receptor Antagonists, Proton Pump Inhibitors (cont.)
Action and Uses
Antacids neutralize hydrochloric acid and decrease gastric pH; inhibit pepsin
Histamine H2-receptor antagonists displace histamine from the receptor site and prevent stimulation of the secretory cells (neutralize acid and promote healing of ulcers)
Proton pump inhibitors irreversibly stop the acid secretory pump imbedded in the parietal cells
Of the three drugs, which classification is considered first-line therapy in the treatment of peptic ulcer disease over 6 to 8 weeks?
What conditions would antacids be used to treat?
How are ulcers caused by Helicobacter pylori treated?
When would proton pump inhibitors be used for long-term therapy?
How do misoprostol and sucralfate differ in their action?

10. Antacids, H2-Receptor Antagonists, Proton Pump Inhibitors (cont.)
Adverse Reactions
Antacids: weakness, anorexia, diarrhea, frequent burping, bowel obstruction, constipation, hypermagnesemia
H2-receptor antagonists: dizziness, headache, somnolence, mild/brief diarrhea, hematology changes, muscle pain
Proton pump inhibitors: headache, diarrhea, abdominal pain, and nausea; rarely rash, vomiting, and dizziness
If the patient overuses antacids that contain magnesium, what symptoms might appear?
Which antibiotic should not be taken with antacids?
Which drugs, when combined with proton pump inhibitors, may produce serious overdose for the patient?

11. Antacids, H2-Receptor Antagonists, Proton Pump Inhibitors (cont.)
Drug Interactions
Antacids prevent absorption of many drugs
Dicumarol absorbed 50% faster when taken with antacids
What are some other examples of drug interactions?

12. Antacids, H2-Receptor Antagonists, Proton Pump Inhibitors (cont.)
Nursing Implications and Patient Teaching
Assessment: interaction possibilities
Diagnosis: smoking/alcohol intake, stress
Planning: increase fluid intake
Implementation: forms and routes of administration vary
Evaluation: continued symptoms of GI distress
Patient and Family Teaching: administration times and drug specificity, adverse reactions, drug storage and efficacy, medical follow-up, drug interactions
What administration considerations will the nurse note if the patient is receiving an antacid and an enteric-coated drug scheduled for the same time each day?
If the patient is receiving an aluminum-containing antacid, the diet should contain adequate amounts of phosphorus. What foods are naturally high in phosphorus?
If the patient is unable to swallow a proton pump inhibitor whole, what might be considered?
When is the best time to administer an oral proton pump inhibitor?

13. Anticholinergics and Antispasmodics
Motility
Symptoms
Classes of medications: anticholinergics, antispasmodics, antidiarrheals
Table 18-2
What contributes to the GI discomfort patients often feel?
The anticholinergic-antispasmodic agents act with antacids in prolonging or continuing the therapeutic benefits of both drug categories.

14. Anticholinergics and Antispasmodics (cont.)
Action and Uses
Anticholinergic-antispasmodic preparations reduce GI tract spasm and intestinal motility, acid production, and gastric motility, thus reducing pain
Use: peptic ulcer, pylorospasm, biliary colic, hypermotility, irritable colon, and acute pancreatitis
Antidiarrheals reduce the fluid content of the stool and decrease peristalsis and motility of the intestinal tract; increase smooth-muscle tone and diminish secretions
Use: treatment of nonspecific diarrhea or diarrhea caused by antibiotics
Why would a GI motility agent be prescribed for an elderly patient with gastroesophageal reflux disease?
When would it be inadvisable to use an antidiarrheal agent for a patient who has diarrhea?
What is the action of bismuth salts on the intestines?

15. Anticholinergics and Antispasmodics (cont.)
Adverse Reactions
Anticholinergics: due to high dosages
Antidiarrheals
If an anticholinergic contains phenobarbital, what adverse reactions should the patient be monitored for?
What is a common adverse reaction associated with long-term use of antidiarrheals?

16. Anticholinergics and Antispasmodics (cont.)
Drug Interactions
New GI stimulants, when combined with other drugs that inhibit cytochrome P-450 4A4 systems, should be monitored for cardiac dysrhythmias
Nursing Implications and Patient Teaching
Assessment, diagnosis, planning, implementation, and evaluation
If anticholinergics containing phenobarbital are combined with anticoagulants without a dosage adjustment, what type of complications could the patient be at risk for?
What important questions should the LPN/LVN ask when completing a nursing assessment for GI disorders?
The nurse should review the patient’s hydration and nutrition status, especially assessing for dehydration in elderly clients.
What dietary considerations should the nurse teach the patient who has diarrhea?

17. Laxatives Aid in the elimination of stool from the rectum
Bulk-forming agents
Fecal softeners
Hyperosmolar or saline solutions
Lubricants
Stimulant or irritant laxatives
Tables 18-3 and 18-4
How does the use of laxatives relate to a patient’s age?
When is regular use of laxatives indicated? What problems may arise with regular laxative use?
Can you identify a procedure in which laxatives may be indicated as patient preparation?

18. Laxatives (cont.) Action and Uses
Bulk-forming laxatives absorb water and expand, increasing the bulk and moisture content of the stool; peristalsis increases, and absorbed water softens the stool
Fecal softeners lower the surface tension, which allows the fecal mass to be softened by intestinal fluids
Hyperosmolar laxatives produce an osmotic effect by drawing water into the bowel, thereby promoting peristalsis and bowel movement
Fecal softeners may inhibit the reabsortion of what two products by the intestine?
What conditions other than constipation are bulk-forming laxatives used to treat?
Why would a stool softener be indicated for the patient after rectal or cardiac surgery?
Saline laxatives may be used as a bowel prep before diagnostic and surgical procedures.
A patient on prolonged bedrest may be prescribed which type of laxative?

19. Laxatives (cont.) Action and Uses (cont.)
Lubricant laxatives create a barrier between feces and the colon, preventing colon reabsorption and causing softening of the stool
Stimulant or irritant laxatives work according to the agent

20. Laxatives (cont.) Adverse Reactions
Nausea and vomiting, obstruction, hypersensitivity
Cramping, diarrhea
Electrolyte disturbances
Why is it important to provide sufficient liquids to patients receiving laxatives?
If a patient has a history of chronic renal failure and is receiving a hyperosmolar laxative, what is he or she at risk of developing?
Which two electrolyte values may be abnormal with excessive laxative use?

21. Laxatives (cont.) Drug Interactions
Reduced effectiveness of antibiotics, anticoagulants, digitalis, and salicylates when combined with laxatives
Nursing Implications and Patient Teaching
Assessment (CHF)
Why is the use of mineral oil combined with a laxative contraindicated?
If the patient chronically misuses laxatives, what clinical condition may result?
What medical conditions contraindicate the use of laxatives? Why?
What nutritional education for preventing constipation should the nurse provide to the patient?
In addition to education about fecal softeners, what nonpharmacologic education should the patient receive?

22. Miscellaneous Gastrointestinal Drugs
Antiflatulents
Pancreatic digestive enzymes
Emetics
Disulfiram
Table 18-5
How does simethicone work as an antiflatulent?
When would the use of an emetic be contraindicated?

23. Antiflatulents
Break up and prevent mucus-surrounded pockets of gas from forming in the intestine; reduce gastric pain
Intended for short-term use
When is the use of activated charcoal indicated?
What physical assessments would the nurse observe in the patient who has excessive gas?
Antiflatulents are often used in combination with what other GI drug?

24. Gallstone-Solubilizing Agents
Act on the liver to suppress cholesterol and cholic acid synthesis; biliary cholesterol desaturation is enhanced, and breakup occurs
Used in selected patients with radiolucent stones in gallbladder
Adverse reactions: dose related; diarrhea, anorexia, constipation, cramps, dyspepsia, epigastric distress, flatulence, heartburn, nausea, nonspecific abdominal pain, and vomiting
What patient characteristics and/or history warrant the use of these agents?
If the patient complains of epigastric pain, where would the pain be located?
Which other drug may reduce the absorption of these medications?
What type of diet education would the patient with a history of gallstones benefit from?

25. Digestive Enzymes
Promote digestion by acting as replacement therapy when the body’s natural pancreatic enzymes are lacking, not secreted, or not properly absorbed
For which clinical conditions would these enzymes be indicated?
Why is proper dietary balance of fat, protein, and starch indicated for the patient who is receiving these enzymes?
If the patient is receiving supplemental iron while on these enzymes, what side effect can occur?
When are digestive enzymes usually scheduled to be given?
What other patient education should be offered to patients taking these preparations?

26. Disulfiram Used in the management of alcoholism
Unpleasant reaction when combined with alcohol
What symptoms would the patient experience if this drug were taken with alcohol?
What physiologic condition within the body produces the disulfiram reaction?
What other medication, when taken with alcohol, produces a reaction similar to the disulfiram-alcohol reaction?
Why is it important for the patient to carefully read label ingredients (food, personal care items, over-the-counter medications) while on this drug?

27. Emetics Used in emergencies to induce vomiting Poison Control Center
Gastric lavage
Syrup of ipecac
Apomorphone
Why should the LPN/LVN consult a Poison Control Center before inducing vomiting?
If inducing vomiting is contraindicated, what would the indicated treatment be?
What amount of time is indicated between poison ingestion time and drug administration time?
Which emetic is given IV?
When would gastric lavage be indicated in the treatment of poisoning?
Why should emetics never be used for unconscious patients?

28. Complementary and Alternative Therapies
Common products
Conditions
Drug interactions
Which of these products potentiate bleeding when combined with anticoagulants, aspirin, antiplatelet drugs, or NSAIDs?