Proton Pump Inhibitors and Acid Secretion Quiz

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Questions and Answers

What stimulates histamine release from ECL cells?

Hyperacidity

Hypochlorhydria

Hypoglycemia

Hypergastrinemia (correct)

Which drug inhibits acid secretion by 75-95% and stimulates mucin and bicarbonate secretion?

Sucralfate

Ranitidine

Omeprazole

Misoprostol (correct)

What is a common adverse effect of Misoprostol?

Constipation

Headache

Nausea

Diarrhea (correct)

Which condition is contraindicated for Misoprostol use due to its effect on uterine contractions?

Pregnancy Signup and view all the answers

Which drug is a sulfated polysaccharide plus aluminium hydroxide used for gastric defense?

Sucralfate Signup and view all the answers

What is the primary function of somatostatin in the regulation of gastric acid secretion?

Inhibiting acid secretion from parietal cells Signup and view all the answers

What is the primary mechanism of action of Proton Pump Inhibitors (PPIs) in reducing acid secretion?

Irreversibly inhibiting the proton pump Signup and view all the answers

Which of the following mediators is responsible for stimulating histamine release from ECL cells in the gastric mucosa?

Gastrin Signup and view all the answers

How do Asians with a slow metabolizing genotype of CYP2C19 react to Proton Pump Inhibitors (PPIs)?

They are more sensitive and likely to suffer toxicity from PPIs Signup and view all the answers

How does the lower esophageal sphincter (LES) help prevent gastroesophageal reflux disease (GERD)?

By tightening to prevent acid reflux into the esophagus 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?

Esomeprazole 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?

Histamine H2 receptor antagonists Signup and view all the answers

What is a potential adverse effect of stopping Proton Pump Inhibitors (PPIs) therapy?

Hypergastrinemia and rebound hypersecretion 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?

Irreversibly inhibiting the H+/K+ ATPase pump Signup and view all the answers

Histamine H2 receptor antagonists inhibit acid secretion by blocking which type of receptors on gastric parietal cells?

Histamine H1 receptors 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?

Releasing bicarbonate and mucus 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.

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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.