Podcast Beta
Questions and Answers
What stimulates histamine release from ECL cells?
Which drug inhibits acid secretion by 75-95% and stimulates mucin and bicarbonate secretion?
What is a common adverse effect of Misoprostol?
Which condition is contraindicated for Misoprostol use due to its effect on uterine contractions?
Signup and view all the answers
Which drug is a sulfated polysaccharide plus aluminium hydroxide used for gastric defense?
Signup and view all the answers
What is the primary function of somatostatin in the regulation of gastric acid secretion?
Signup and view all the answers
What is the primary mechanism of action of Proton Pump Inhibitors (PPIs) in reducing acid secretion?
Signup and view all the answers
Which of the following mediators is responsible for stimulating histamine release from ECL cells in the gastric mucosa?
Signup and view all the answers
How do Asians with a slow metabolizing genotype of CYP2C19 react to Proton Pump Inhibitors (PPIs)?
Signup and view all the answers
How does the lower esophageal sphincter (LES) help prevent gastroesophageal reflux disease (GERD)?
Signup and view all the answers
Which of the following drugs is known to interact with clopidogrel by preventing its conversion to the active form?
Signup and view all the answers
Which class of drugs is known for their ability to inhibit the secretion of gastric acid by parietal cells?
Signup and view all the answers
What is a potential adverse effect of stopping Proton Pump Inhibitors (PPIs) therapy?
Signup and view all the answers
What is the main mechanism of action of proton pump inhibitors (PPIs) in the treatment of acid-related disorders?
Signup and view all the answers
Histamine H2 receptor antagonists inhibit acid secretion by blocking which type of receptors on gastric parietal cells?
Signup and view all the answers
Which of the following is a mechanism used by the stomach to protect its mucosa against acid and pepsin damage?
Signup and view all the answers
Study Notes
Regulation of Gastric Acid Secretion
- Gastric acid secretion may be stimulated by hypergastrinemia, which releases histamine from ECL cells.
Drugs to Increase Mucosal Defense
-
Misoprostol: a prostaglandin E1 analogue that stimulates EP3 receptors on parietal cells, decreasing cAMP and inhibiting acid secretion by 75-95%.
-
Misoprostol also stimulates mucin and bicarbonate secretion, which are protective for the stomach mucosa.
-
Adverse effects of misoprostol: diarrhea in up to 30% of patients, abdominal cramps, and may aggravate inflammatory bowel disease.
-
Misoprostol is contraindicated during pregnancy due to uterine contractions.
-
Sucralfate: a sulfated polysaccharide plus aluminum hydroxide that stimulates mucus secretion at an acidic pH.
Drugs to Reduce Acid Secretion
-
Proton Pump Inhibitors (PPIs): most potent in reducing acid secretion (80-95% inhibition).
-
PPIs are prodrugs activated by acid in parietal cells and irreversibly inhibit the proton pump.
-
Adverse effects of PPIs: can interact with other drugs, inhibit their metabolism, and cause hypergastrinemia upon stopping treatment.
-
Therapeutic uses of PPIs: gastric and duodenal ulcers, GERD, and Zollinger-Ellison syndrome.
-
Histamine H2 Receptor Antagonists: less potent than PPIs, inhibit acid secretion by ~70%.
-
Mechanism: block histamine H2 receptors on gastric parietal cells.
-
Adverse effects: mostly minor, but cimetidine interacts with many drugs and tolerance to their acid-suppressing effect occurs within 2-3 days of use.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on Proton Pump Inhibitors (PPIs) and their mechanism of action in reducing acid secretion in the stomach. Learn about the drugs omeprazole, esomeprazole, lansoprazole, rabeprazole, and pantoprazole, as well as their role in treating acid-related disorders.
