Chapter 32: Pharmacotherapy of Gastric Acidity, Peptic Ulcers, and Gastroesophageal Reflux Disease
A 24-year-old woman presents with symptoms of esophageal reflux. She is 6 months pregnant. Which of the following drugs is contraindicated in this patient?
e. Aluminum hydroxide antacid
Answer is c. Misoprostol is contraindicated in pregnancy because it can increase uterine contractility.
A 48-year-old man with a duodenal ulcer disease is treated with cimetidine. After 6 weeks of treatment, he complains that his stomach pain is returning and wonders if the dose of cimetidine should be increased. The most likely reason for the decreased effectiveness of cimetidine in this patient is
b. diminished GI absorption.
c. enhanced plasma protein binding.
d. increased hepatic metabolism.
e. poor patient compliance.
Answer is a. H2 receptor antagonists are known to produce tolerance. One cause for this tolerance is the secondary increase in gastrin which stimulates histamine release and overcomes the H2 receptor blockade.
Esomeprazole has a plasma half-life of a few hours yet suppresses acid secretion for 24 to 48 hours. The reason for this paradox is
a. acid suppression continues until new H+,K+-ATPase molecules are synthesized.
b. gastrin depletion occurs long after esomeprazole disappears from the plasma.
c. prostaglandin synthesis is enhanced by esomeprazole.
d. H. pylori is effectively suppressed by esomeprazole for 24 to 48 hours.
e. acid suppression continues until new H2 receptors are synthesized.
Answer is a. Proton pump inhibitors irreversible bind to the H+,K+-ATPase and suppress acid secretion by the gastric parietal cell until new pump molecules are synthesized.
A 48-year-old woman has been diagnosed with a duodenal ulcer that is complicated by H. pylori infection. A suitable therapeutic regimen for this patient would be
b. a single antibiotic plus a proton pump inhibitor.
c. misoprostol plus a proton pump inhibitor.