Peptic Ulcer: Causes and Treatment

What is the primary cause of peptic ulcer?

What is the effect of prostaglandin E2 on gastric acid secretion?

What is the role of somatostatin in gastric acid secretion?

What is the primary target of treatment for peptic ulceration?

What is the mechanism of action of histamine on gastric acid secretion?

What is the primary mechanism by which proton pump inhibitors irreversibly inactivate the Na+/K+ ATPase enzyme?

What is the recommended timing for taking proton pump inhibitors to maximize their effect?

Why should H2-receptor antagonists be taken after proton pump inhibitors?

What is a potential long-term consequence of prolonged hypochlorhydria induced by proton pump inhibitors?

What is a unique endocrine effect of cimetidine that is not seen with other H2-receptor antagonists?

Peptic Ulcer

Occurs due to an imbalance between aggressive factors (gastric acid and pepsin) and defensive mechanisms (gastric and duodenal mucosa)
Major causes: NSAIDs use, especially in the elderly, and smoking
Smoking is a major environmental factor, and patients should be advised to quit

Gastric Acid Secretion

Secreted by parietal cells in gastric mucosa
Stimulated by gastrin, histamine, and acetylcholine, which bind to receptors on basolateral membranes
Inhibited by prostaglandin E2 and somatostatin
Acetylcholine and gastrin increase intracellular calcium levels, while histamine activates adenylyl cyclase

Inhibition and Neutralization of Gastric Acid

Proton pump inhibitors (PPIs): omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole
Mode of action: irreversibly inhibit Na+/K+ ATPase, reducing acid secretion
Therapeutic uses: erosive esophagitis, active duodenal ulcer, Zollinger-Ellison syndrome, GERD, and H. pylori eradication

Proton Pump Inhibitors (PPIs)

Omeprazole is a prodrug, which becomes ionized in acidic media and binds to sulphydryl groups on Na+/K+ ATPase
Given in enteric-coated tablets due to degradation at low pH
Adverse effects: nausea, headache, diarrhea, constipation, rash, and interactions with warfarin, diazepam, carbamazepine, and phenytoin
Long-term use may increase risk of gastric carcinoid tumors, reduce vitamin B12 absorption, and increase susceptibility to GIT infections

H2 Receptor Antagonists

Examples: cimetidine, ranitidine, famotidine, nizatidine
Therapeutic uses: peptic ulcers, acute stress ulcers, and gastroesophageal reflux disease
Adverse effects: headache, dizziness, diarrhea, muscular pain, CNS effects (confusion, hallucinations), and endocrine effects (antiandrogenic effects)

Test your knowledge on peptic ulcers, its causes, symptoms, and treatment options. Learn about the imbalance between gastric acid and defense mechanisms, and how NSAIDs and smoking contribute to the disease. Explore the different approaches to treating peptic ulceration.