27 Drugs Used to Treat Gastrointestinal Conditions

Multimedia Directory Slide 4 Digestive System Animation

Figure 27-1 The digestive system.

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

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

Table 27-1 Drugs Commonly Used in Peptic Ulcer Disease

Table 27-1 (continued) Drugs Commonly Used in Peptic Ulcer Disease

Table 27-1 (continued) Drugs Commonly Used in Peptic Ulcer Disease

Antacids: Uses Alkaline compounds that neutralize hydrochloric acid Most common types contain aluminum hydroxide and magnesium carbonate.

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

Antacids: Contraindications Contraindicated in patients with hypercalcemia, hyperparathyroidism, vitamin D-overdosage, and decalcifying tumors (depending on type of antacid) Cautious use in patients with impaired kidney function or dialysis, and in lactation

Antacids: Patient Information Instruct patients to take antacids 1 to 3 hours after meals and at bedtime, and not within 1 to 2 hours of 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.

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

H2-receptor Antagonists: Uses H2-receptor antagonists reduce secretion of gastric acid by blocking H2-receptors Used in short-term treatment of active duodenal ulcers and prevention of ulcer recurrence Also used for heartburn

H2-receptor Antagonists: Adverse Effects Common: GI disturbances, headache, drowsiness, confusion, agitation, hallucinations, and reversible impotence Serious: cardiac arrhythmias and cardiac arrest after IV bolus dose

H2-receptor Antagonists: Contraindications The agents are contraindicated in: Pregnancy and lactation Children younger than 16 years of age

H2-receptor Antagonists: Patient Information Warn patients to avoid smoking and drinking alcohol.

Proton Pump Inhibitors: Uses Act by blocking hydrochloric acid production Used to heal stomach and duodenal ulcers and relieve symptoms of GERD and esophagitis

Proton Pump Inhibitors: Adverse Effects Common: headache, dizziness, fatigue, diarrhea, abdominal pain, nausea Rare: hematuria

Proton Pump Inhibitors: Contraindications Long-term use is contraindicated. Should not be used in children younger than 18 years

Proton Pump Inhibitors: Patient Information Advise patients that treatment is for short term only (4–8 weeks).

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

Prostaglandins: Uses Affect GI motility and gastric acid secretion Used to prevent complications of gastric ulcers that result from NSAID use

Prostaglandins: Adverse Effects and Contraindications Common adverse effects are: diarrhea and menorrhagia (in women) Contraindicated in pregnancy and lactation

Prostaglandins: Patient Information Advise women to immediately report pregnancy. Advise patients that diarrhea may occur but will disappear after the first month of therapy.

Table 27-2 Classifications of Antidiarrheal Drugs

Table 27-3 The Most Common Antidiarrheals

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

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

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

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.

Opioids in Elderly Patients Monitor opioid use in elderly patients carefully because opioids can cause respiratory depression and decreased blood pressure in this population.

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.

Table 27-4 Categories of Laxatives

Table 27-4 (continued) Categories of Laxatives

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

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

Osmotic Laxatives: Contraindications Contraindicated in renal impairment and hypertension

Osmotic 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.

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.

Stool Softeners Uses: to ease bowel movements in constipated patients Adverse effects: mild abdominal cramps, diarrhea, nausea Contraindications: Atonic constipation, abdominal pain, intestinal obstruction, heart failure, edema, diabetes

Stool Softeners Patient education: Instruct patients to drink lots of fluids and not use these drugs for a long period.

Laxative Stimulants Uses: temporary relief of constipation Adverse effects: anorexia, nausea, gripping, rebound constipation, melanosis Contraindications: abdominal pain, fecal impaction, GI bleeding, ulcerations, pregnancy, heart failure

Laxative Stimulants Patient education: Advise patients that prolonged use disrupts normal colon function.

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

Bulk-forming Laxatives Patient education: Advise patients with diabetes that these drugs contain sugar.

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.

Table 27-5 The Most Commonly Used Antiemetics

Table 27-5 (continued) The Most Commonly Used Antiemetics

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.