1. Focus on Pharmacology Essentials for Health Professionals
Jahangir Moini, MD, MPH
Chapter 24 Effects of Drugs on the Gastrointestinal Disorders

2. Liver Center of metabolic activity in body
Detoxifies blood and secretes bile

3. Peptic Ulcers Caused by hyperacidity and excessive pepsin activity
Alcohol, caffeine, and smoking have been linked to peptic ulcers.
Many cases of gastric ulcers or gastritis are due to Helicobacter pylori (bacteria that causes illness)

4. Antacids: Uses Alkaline compounds that neutralize hydrochloric acid
Most commons contain aluminum and magnesium carbonate

5. Antacids: Adverse Effects
Common: diarrhea or constipation, anorexia, weakness, bone pain, tremors
Hypermagnesemia may produce nausea, vomiting, confusion, renal calculi, and headache.

6. Antacids: Contraindications
Contraindicated in patients with hypercalcemia, hyperparathyroidism, and vitamin D–overdosage
Cautious use in patients with impaired kidney function or dialysis, and in lactation

7. Antacids: Patient Information
Instruct patients to take antacids 1 to 3 hours after meals and at bedtime, and not within 1 to 2 hours or taking other oral medications.
Advise patients to increase fluid intake to prevent kidney stones.
Patients with cardiovascular disease should avoid antacids that are high in sodium.

8. Tums Use by Older Adults
Calcium carbonate (Tums) should be used with caution in older adults. This is because of their likelihood of having the following disorders:
Renal disease or calculi
Ventricular fibrillation
Cardiovascular disease

9. OTC Gastric Medications in Children
Omeprazole (Prilosec and Zegerid) has not been significantly tested in children.
Do not use in children younger than 18.

10. Opioids: Uses
Narcotic analgesics act as stimulants on opioid receptors in the GI tract to increase mixing movements of the gut and decrease peristatic movements
Used to treat diarrhea

11. Opioids: Adverse Effects
Constipation
Nausea and vomiting
Agitation
Drowsiness
Tachycardia
Numbness of hands and feet

12. Opioids: Contraindications
Contraindicated in intestinal obstruction and in children younger than 6 years
Not recommended for treatment of chronic diarrhea

13. Opioids: Patient Information
Encourage patients to keep a record of bowel movements to determine effectiveness or possible constipation.
Advise patients to drink clear fluids for a few days.

14. Absorbents Absorb toxins in GI tract that might be causing diarrhea
Adverse effects: constipation
Contraindications: bowel obstruction, colitis, fever, pregnancy, lactation
Patient education: Instruct patients to report diarrhea that is not controlled within 48 hours.

15. Laxatives: Uses
Sodium and magnesium ions attract water into bowel causing a more liquid stool.
Used for short-term treatment of occasional constipation.

16. Laxatives: Adverse Effects
Common: nausea, vomiting, abdominal cramps, diarrhea, weakness, lethargy, electrolyte imbalances
Serious: hypotension, bradycardia, mental depression, coma

17. Laxatives: Contraindications
Contraindicated in renal impairment and hypertension

18. Laxatives: Patient Education
Instruct patients that 24 to 48 hours are needed for effect to occur.
Women should not breast feed while taking these drugs.

19. Laxative Abuse
Evaluate laxative use in patients suspected of having bulimia or anorexia.
Elderly patients may perceive constipation and overuse laxatives. Be alert for volume depletion in older adults.

20. Stool Softeners Uses: to ease bowel movements in constipated patients
Adverse effects: mild abdominal cramps, diarrhea, nausea
Contraindications: Atonic constipation (failure of the colon to respond to normal stimulation), abdominal pain, intestinal obstruction, heart failure, edema, diabetes
Patient education: Instruct patients to drink lots of fluids and not use these drugs for a long period.

21. Laxative Stimulants Uses: temporary relief of constipation
Adverse effects: anorexia, nausea, rebound constipation
Contraindications: Abdominal pain, fecal impaction, GI bleeding, ulcerations, pregnancy, heart failure
Patient education: Advise patients that prolonged use disrupts normal colon function.

22. Bulk-forming Laxatives
Work by absorbing free water in intestinal tract; use in atonic or spastic constipation
Adverse effects: nausea, vomiting, diarrhea, abdominal cramps
Contraindications: esophageal and intestinal obstruction, fecal impaction, children younger than 2 years
Patient education: Advise patients with diabetes that these drugs contain sugar.

23. Emetics Use: to induce vomiting (emergency)
Adverse effects: stiff muscles, myopathy, convulsions, coma, arrhythmias, fatal myocarditis
Contraindications: shock, seizures, impaired cardiac function, sedation
Patient education: Advise patients not to use before calling poison control center

24. Antiemetics Uses: to prevent or treat nausea and vomiting
Adverse effects: drowsiness, dry mouth, confusion, hypotension, blurred vision
Contraindications: coma, CNS depression, pregnancy, and lactation
Patient education: Advise patients to avoid driving and alcohol.