Pharmacology Made Easy 4.0 Gastrointestinal System Questions and Answers | Latest Version | 2025/2026 | Correct & Verified

Pharmacology Made Easy 4.0 Gastrointestinal System Questions and Answers | Latest Version | 2025/2026 | Correct & Verified What is the primary mechanism of action of proton pump inhibitors? Proton pump inhibitors irreversibly block the H+/K+ ATPase enzyme in gastric parietal cells, reducing acid production. Why are antacids typically administered after meals? Antacids work best when taken after meals because food slows gastric emptying, allowing longer contact time with stomach acid. How does sucralfate protect ulcerated gastrointestinal tissue? Sucralfate forms a viscous adhesive barrier that binds to ulcer sites, protecting them from acid and pepsin. What makes misoprostol useful for preventing NSAID-induced gastric ulcers? Misoprostol is a prostaglandin analog that enhances mucosal defense mechanisms and reduces acid secretion. 2 Why must tetracycline antibiotics be spaced apart from antacids? Antacids containing aluminum, calcium, or magnesium can chelate tetracyclines, significantly reducing their absorption. What is the key difference between loperamide and diphenoxylate in treating diarrhea? Loperamide acts solely on peripheral opioid receptors in the gut, while diphenoxylate has central nervous system effects at higher doses. How does ondansetron prevent chemotherapy-induced nausea? Ondansetron selectively blocks 5-HT3 serotonin receptors in the gut and chemoreceptor trigger zone, inhibiting nausea signals. Why is vitamin B12 supplementation necessary with long-term PPI use? Proton pump inhibitors reduce gastric acid needed to release vitamin B12 from food proteins, potentially causing deficiency. What makes lubiprostone different from other laxatives? 3 Lubiprostone activates chloride channels to increase intestinal fluid secretion, promoting bowel movements without stimulating nerves. Why must metoclopramide be used cautiously in elderly patients? Metoclopramide can cause tardive dyskinesia and other extrapyramidal symptoms, especially in older adults with prolonged use. How does rifaximin treat traveler's diarrhea differently than systemic antibiotics? Rifaximin is a non-absorbed antibiotic that acts locally in the gut with minimal systemic effects or disruption of normal flora. What is the advantage of pancrelipase over regular pancreatic enzyme supplements? Pancrelipase contains higher concentrations of lipase, protease, and amylase in a more stable formulation for pancreatic insufficiency. Why must aluminum-containing antacids