Comprehensive Gastrointestinal
Pharmacology Test Bank: Practice
Questions 1–150 Answers And
Rationale
2025/2026
1. Which of the following drugs is a proton pump inhibitor used to
treat GERD?
a) Ranitidine
b) Famotidine
c) Omeprazole
d) Sucralfate
Rationale: Omeprazole is a proton pump inhibitor (PPI) that
irreversibly inhibits the H+/K+ ATPase in gastric parietal cells,
reducing acid secretion.
2. Which drug is classified as an H2 receptor antagonist?
a) Ranitidine
b) Omeprazole
c) Misoprostol
d) Aluminum hydroxide
Rationale: Ranitidine blocks H2 receptors on gastric parietal cells,
reducing acid production.
3. A patient with peptic ulcer disease is prescribed a cytoprotective
agent. Which drug fits this category?
a) Esomeprazole
b) Sucralfate
, c) Metoclopramide
d) Loperamide
Rationale: Sucralfate forms a protective barrier over ulcers, shielding
them from acid and pepsin.
4. Which of the following is a prokinetic agent that enhances
gastrointestinal motility?
a) Omeprazole
b) Metoclopramide
c) Lansoprazole
d) Ranitidine
Rationale: Metoclopramide increases gastric emptying and
gastrointestinal motility by antagonizing dopamine D2 receptors.
5. A patient has diarrhea caused by traveler's diarrhea. Which
antidiarrheal agent is appropriate?
a) Bismuth subsalicylate
b) Loperamide
c) Misoprostol
d) Sucralfate
Rationale: Loperamide slows intestinal motility and increases
absorption, reducing diarrhea.
6. Which of the following medications is used to prevent NSAID-
induced gastric ulcers?
a) Omeprazole
b) Ranitidine
c) Misoprostol
d) Aluminum hydroxide
Rationale: Misoprostol is a prostaglandin E1 analog that increases
mucus and bicarbonate secretion, protecting the stomach lining.
, 7. Which drug neutralizes stomach acid by chemically reacting with
it?
a) Omeprazole
b) Ranitidine
c) Magnesium hydroxide
d) Metoclopramide
Rationale: Magnesium hydroxide is an antacid that directly
neutralizes gastric acid to increase pH.
8. A patient with gastroesophageal reflux disease (GERD) is advised
to take a drug that irreversibly inhibits acid secretion. Which is
recommended?
a) Ranitidine
b) Pantoprazole
c) Sucralfate
d) Aluminum hydroxide
Rationale: Pantoprazole is a PPI that irreversibly inhibits H+/K+
ATPase, providing potent acid suppression.
9. Which of the following is a bulk-forming laxative?
a) Bisacodyl
b) Psyllium
c) Magnesium citrate
d) Docusate sodium
Rationale: Psyllium absorbs water and forms a gel, increasing stool
bulk and promoting bowel movements.
10. Which laxative works by stimulating intestinal smooth
muscle?
a) Psyllium
b) Docusate sodium
, c) Bisacodyl
d) Lactulose
Rationale: Bisacodyl stimulates enteric nerves, enhancing peristalsis.
11. Which osmotic laxative is safe for long-term use in hepatic
encephalopathy?
a) Magnesium hydroxide
b) Lactulose
c) Bisacodyl
d) Senna
Rationale: Lactulose reduces ammonia absorption in the gut and is
used in hepatic encephalopathy management.
12. Which drug can be used as an antiemetic by blocking
serotonin 5-HT3 receptors?
a) Metoclopramide
b) Prochlorperazine
c) Ondansetron
d) Dimenhydrinate
Rationale: Ondansetron selectively blocks 5-HT3 receptors in the GI
tract and chemoreceptor trigger zone, preventing nausea and
vomiting.
13. Which antiemetic is a dopamine D2 receptor antagonist?
a) Ondansetron
b) Dimenhydrinate
c) Prochlorperazine
d) Meclizine
Rationale: Prochlorperazine blocks dopamine receptors in the
chemoreceptor trigger zone to prevent nausea.
Pharmacology Test Bank: Practice
Questions 1–150 Answers And
Rationale
2025/2026
1. Which of the following drugs is a proton pump inhibitor used to
treat GERD?
a) Ranitidine
b) Famotidine
c) Omeprazole
d) Sucralfate
Rationale: Omeprazole is a proton pump inhibitor (PPI) that
irreversibly inhibits the H+/K+ ATPase in gastric parietal cells,
reducing acid secretion.
2. Which drug is classified as an H2 receptor antagonist?
a) Ranitidine
b) Omeprazole
c) Misoprostol
d) Aluminum hydroxide
Rationale: Ranitidine blocks H2 receptors on gastric parietal cells,
reducing acid production.
3. A patient with peptic ulcer disease is prescribed a cytoprotective
agent. Which drug fits this category?
a) Esomeprazole
b) Sucralfate
, c) Metoclopramide
d) Loperamide
Rationale: Sucralfate forms a protective barrier over ulcers, shielding
them from acid and pepsin.
4. Which of the following is a prokinetic agent that enhances
gastrointestinal motility?
a) Omeprazole
b) Metoclopramide
c) Lansoprazole
d) Ranitidine
Rationale: Metoclopramide increases gastric emptying and
gastrointestinal motility by antagonizing dopamine D2 receptors.
5. A patient has diarrhea caused by traveler's diarrhea. Which
antidiarrheal agent is appropriate?
a) Bismuth subsalicylate
b) Loperamide
c) Misoprostol
d) Sucralfate
Rationale: Loperamide slows intestinal motility and increases
absorption, reducing diarrhea.
6. Which of the following medications is used to prevent NSAID-
induced gastric ulcers?
a) Omeprazole
b) Ranitidine
c) Misoprostol
d) Aluminum hydroxide
Rationale: Misoprostol is a prostaglandin E1 analog that increases
mucus and bicarbonate secretion, protecting the stomach lining.
, 7. Which drug neutralizes stomach acid by chemically reacting with
it?
a) Omeprazole
b) Ranitidine
c) Magnesium hydroxide
d) Metoclopramide
Rationale: Magnesium hydroxide is an antacid that directly
neutralizes gastric acid to increase pH.
8. A patient with gastroesophageal reflux disease (GERD) is advised
to take a drug that irreversibly inhibits acid secretion. Which is
recommended?
a) Ranitidine
b) Pantoprazole
c) Sucralfate
d) Aluminum hydroxide
Rationale: Pantoprazole is a PPI that irreversibly inhibits H+/K+
ATPase, providing potent acid suppression.
9. Which of the following is a bulk-forming laxative?
a) Bisacodyl
b) Psyllium
c) Magnesium citrate
d) Docusate sodium
Rationale: Psyllium absorbs water and forms a gel, increasing stool
bulk and promoting bowel movements.
10. Which laxative works by stimulating intestinal smooth
muscle?
a) Psyllium
b) Docusate sodium
, c) Bisacodyl
d) Lactulose
Rationale: Bisacodyl stimulates enteric nerves, enhancing peristalsis.
11. Which osmotic laxative is safe for long-term use in hepatic
encephalopathy?
a) Magnesium hydroxide
b) Lactulose
c) Bisacodyl
d) Senna
Rationale: Lactulose reduces ammonia absorption in the gut and is
used in hepatic encephalopathy management.
12. Which drug can be used as an antiemetic by blocking
serotonin 5-HT3 receptors?
a) Metoclopramide
b) Prochlorperazine
c) Ondansetron
d) Dimenhydrinate
Rationale: Ondansetron selectively blocks 5-HT3 receptors in the GI
tract and chemoreceptor trigger zone, preventing nausea and
vomiting.
13. Which antiemetic is a dopamine D2 receptor antagonist?
a) Ondansetron
b) Dimenhydrinate
c) Prochlorperazine
d) Meclizine
Rationale: Prochlorperazine blocks dopamine receptors in the
chemoreceptor trigger zone to prevent nausea.
