Acid-Controlling Drugs Flashcards
Peptic Ulcer Disease
Gastric or duodenal ulcers that involve digestion of the GI mucosa by the enzyme pepsin
H. Pylori
Bacterium found in the GI tract in 90% of patients with duodenal ulcers and 70% of those with gastric ulcers
First-line therapy includes a 10 to 14 day course of a proton pump inhibitor and antibiotics
Stress-Related Mucosal Damage
GI lesions are common in ICU patients
Factors include decreased blood flow, mucosal ischemia, hypoperfusion, and reperfusion injury
NG tubes and ventilators predispose patients to GI bleeding
Histamine receptor-blocing drug or a proton pump inhibitor are given for prevention
Antacid Mechanism of Action
Do not prevent overproduction of acid but instead help to neutralize stomach acid secretions
Promote gastric mucosal defense mechanisms
Stimulate secretion of mucus, bicarbonate, and prostaglandins
Antacid Drug Effects
Reduction of pain
Increases resistance of stomach lining, increases tone of cardiac sphincter, inhibits the protein-digestion ability of pepsin
Aluminum Salt Antacids
HAVE CONSTIPATING EFFECTS
Often used with magnesium to counteract constipation
Often recommended for patients with renal disease
MAALOX, MYLANTA
Magnesium Salt Antacids
COMMONLY CAUSE DIARRHEA
DANGEROUS WHEN USED WITH RENAL FAILURE (failing kidney cannot excrete extra magnesium)
Calcium Salt Antacids
MAY CAUSE CONSTIPATION, kidney stones
Not recommended for patients with renal disease
Long duration of action
TUMS (CALCIUM CARBONATE)
Sodium Bicarbonate Antacids
Highly soluble, buffers the acidic properties of HCl
Quick onset, short duration
May cause metabolic alkalosis
May cause problems in patients with heart failure, hypertension, or renal insufficiency
Antiflatulents
Used to relieve painful symptoms associated with gas
SIMETHICONE (MYLICON)
Antacid Drug Interactions
Reduces the ability of the other drug to be absorbed in the body
Chelation (chemical binding/inactivation of other drug, produces insoluble complexes –> reduced drug absorption)
Histamine 2 Receptor Antagonists
Reduce acid secretion
Most popular drugs for treatment of acid-related disorders
CIMETIDINE (TAGAMET), FAMOTIDINE (PEPCID)
Histamine 2 Antagonist Mechanism of Action
Block the H2 receptor of acid-producing parietal cells
Increase the pH of the stomach
Indications for Histamine 2 Antagonists
GERD, peptic ulcer disease, erosive esophagitis, adjunct therapy to control upper GI bleeding, Zollinger-Ellison syndrome
Adverse Effects of H2 Antagonists
CENTRAL NERVOUS SYSTEM ADVERSE EFFECTS IN ELDERLY PATIENTS INCLUDE CONFUSION AND DISORIENTATION (ESPECIALLY CIMETIDINE)