Pharmacologic Profile
General Use
Treatment and prophylaxis of peptic ulcer and gastric hypersecretory conditions such as Zollinger-Ellison syndrome. Histamine H2-receptor antagonists (blockers) and proton pump inhibitors are also used in the management of gastroesophageal reflux disease (GERD).
General Action and Information
Because a great majority of peptic ulcer disease may be traced to GI infection with the organism Helicobacter pylori, eradication of the organism ↓ symptomatology and recurrence. Anti-infectives with significant activity against the organism include amoxicillin, clarithromycin, metronidazole, and tetracycline. Bismuth also has anti-infective activity against H. pylori. H. pylori treatment regimens usually include: a proton pump inhibitor, and 2 anti-infectives with or without bismuth subsalicylate for 10–14 days.
Other medications used in the management of gastric/duodenal ulcer disease are aimed at neutralizing gastric acid (antacids), ↓ acid secretion (histamine H2 antagonists, proton pump inhibitors, misoprostol), or protecting the ulcer surface from further damage (misoprostol, sucralfate). Histamine H2-receptor antagonists competitively inhibit the action of histamine at the H2 receptor, located primarily in gastric parietal cells, resulting in inhibition of gastric acid secretion. Misoprostol ↓ gastric acid secretion and ↑ production of protective mucus. Proton pump inhibitors prevent the transport of hydrogen ions into the gastric lumen.
Contraindications
Hypersensitivity. Pregnancy.
Precautions
Most histamine H2 antagonists require dose reduction in renal impairment and in elderly patients. Magnesium-containing antacids should be used cautiously in patients with renal impairment. Misoprostol should be used cautiously in women of reproductive potential.
Interactions
Calcium- and magnesium-containing antacids ↓ the absorption of tetracycline and fluoroquinolones. Cimetidine inhibits the ability of the liver to metabolize several drugs, ↑ the risk of toxicity from warfarin, tricyclic antidepressants, theophylline, metoprolol, phenytoin, propranolol, and lidocaine. Omeprazole ↓ metabolism of phenytoin, diazepam, and warfarin. All agents that ↑ gastric pH will ↓ the absorption of itraconazole, ketoconazole, iron salts, erlotinib, nilotinib, atazanavir, nelfinavir, rilpivirine, and mycophenolate mofetil.
Nursing Implications
Assessment
- Assess patient routinely for epigastric or abdominal pain and frank or occult blood in the stool, emesis, or gastric aspirate.
- Antacids: Assess for heartburn and indigestion as well as the location, duration, character, and precipitating factors of gastric pain.
- Histamine H2 Antagonists: Assess elderly and severely ill patients for confusion routinely. Notify health care professional promptly should this occur.
- Misoprostol: Assess women of reproductive potential for pregnancy. Medication is usually begun on 2nd or 3rd day of menstrual period following a negative serum pregnancy test within 2 wk of beginning therapy.
Potential Nursing Diagnoses
- Acute pain (Indications)
- Deficient knowledge related to disease processes and medication regimen (Patient/Family Teaching)
Implementation
- Antacids: Antacids cause premature dissolution and absorption of enteric-coated tablets and may interfere with absorption of other oral medications. Separate administration of antacids and other oral medications by at least 1 hr.
- Shake liquid preparations well before pouring. Follow administration with water to ensure passage to stomach. Liquid and powder dosage forms are considered to be more effective than chewable tablets.
- Chewable tablets must be chewed thoroughly before swallowing. Follow with half a glass of water.
- Administer 1 and 3 hr after meals and at bedtime for maximum antacid effect.
- Misoprostol: Administer with meals and at bedtime to reduce the severity of diarrhea.
- Proton Pump Inhibitors: Administer before meals, preferably in the morning. Capsules should be swallowed whole; do not open, crush, or chew.
- May be administered concurrently with antacids.
- Sucralfate: Administer on an empty stomach 1 hr before meals and at bedtime. Do not crush or chew tablets. Shake suspension well prior to administration. If nasogastric administration is required, consult pharmacist, as protein-binding properties of sucralfate have resulted in formation of a bezoar when administered with enteral feedings and other medications.
Patient/Family Teaching
- Instruct patient to take medication as directed for the full course of therapy, even if feeling better. If a dose is missed, it should be taken as soon as remembered but not if almost time for next dose. Do not double doses.
- Advise patient to avoid alcohol, products containing aspirin, NSAIDs, and foods that may cause an ↑ in GI irritation.
- Advise patient to report onset of black, tarry stools to health care professional promptly.
- Inform patient that cessation of smoking may help prevent the recurrence of duodenal ulcers.
- Antacids: Caution patient to consult health care professional before taking antacids for more than 2 wk or if problem is recurring. Advise patient to consult health care professional if relief is not obtained or if symptoms of gastric bleeding (black, tarry stools; coffee-ground emesis) occur.
- Misoprostol: Emphasize that sharing of this medication may be dangerous.
- Inform patient that misoprostol may cause spontaneous abortion. Women of reproductive potential must be informed of this effect through verbal and written information and must use contraception throughout therapy. If pregnancy is suspected, the woman should stop taking misoprostol and immediately notify her health care professional.
- Sucralfate: Advise patient to continue with course of therapy for 4–8 wk, even if feeling better, to ensure ulcer healing.
- Advise patient that an ↑ in fluid intake, dietary bulk, and exercise may prevent drug-induced constipation.
Evaluation/Desired Outcomes
- Decrease in GI pain and irritation. Prevention of gastric irritation and bleeding. Healing of duodenal ulcers can be seen by x-rays or endoscopy. Therapy with histamine H2 antagonists is continued for at least 6 wk after initial episode. Decreased symptoms of GERD. Increase in the pH of gastric secretions (antacids). Prevention of gastric ulcers in patients receiving chronic NSAID therapy (misoprostol only).
Antiulcer agents included in Davis's Drug Guide for Nurses
- antacids
- histamine H2 antagonists
- proton-pump inhibitors
- miscellaneous