GI GI Pharmacology & Medications 2 — Questions and Answers
Question 1: What is the primary concern when using NSAIDs in patients with a history of peptic ulcer disease?
- Increased risk of liver toxicity
- Inhibition of prostaglandin synthesis leading to mucosal damage (Correct answer)
- Reduced gastric motility
- Increased bile secretion
Correct answer: Inhibition of prostaglandin synthesis leading to mucosal damage
NSAIDs inhibit COX enzymes, reducing prostaglandin production that normally protects the gastric mucosa, increasing the risk of ulcers and GI bleeding.
Question 2: Which antidiarrheal medication works by stimulating opioid receptors in the gut wall to reduce intestinal motility?
- Bismuth subsalicylate
- Loperamide (Correct answer)
- Diphenoxylate
- Kaolin-pectin
Correct answer: Loperamide
Loperamide acts on mu-opioid receptors in the myenteric plexus to decrease peristalsis and increase anal sphincter tone without crossing the blood-brain barrier.
Question 3: What is sucralfate's mechanism of action in treating peptic ulcers?
- Blocks acid secretion
- Forms a protective barrier over the ulcer site (Correct answer)
- Neutralizes stomach acid
- Eradicates H. pylori
Correct answer: Forms a protective barrier over the ulcer site
Sucralfate binds to the ulcer base in an acidic environment to form a protective coating that shields the mucosa from acid and pepsin.
Question 4: Which drug class is used to manage hepatic encephalopathy by reducing ammonia-producing gut bacteria?
- PPIs
- Non-absorbable antibiotics (rifaximin) (Correct answer)
- H2 blockers
- Antifungals
Correct answer: Non-absorbable antibiotics (rifaximin)
Rifaximin, a non-absorbable antibiotic, reduces ammonia-producing bacteria in the colon, thereby decreasing circulating ammonia levels in hepatic encephalopathy.
Question 5: Which medication is the antidote for acetaminophen-induced hepatotoxicity?
- Naloxone
- N-acetylcysteine (NAC) (Correct answer)
- Flumazenil
- Activated charcoal only
Correct answer: N-acetylcysteine (NAC)
N-acetylcysteine replenishes glutathione stores, neutralizing the toxic NAPQI metabolite responsible for acetaminophen-induced liver damage.
Question 6: Ursodeoxycholic acid (ursodiol) is used to treat which GI condition?
- Crohn's disease
- Primary biliary cholangitis and gallstone dissolution (Correct answer)
- Peptic ulcer disease
- Acute pancreatitis
Correct answer: Primary biliary cholangitis and gallstone dissolution
Ursodiol is a bile acid that reduces cholesterol saturation in bile, used to dissolve cholesterol gallstones and treat primary biliary cholangitis.
GI GI Pharmacology & Medications 2
What is the primary concern when using NSAIDs in patients with a history of peptic ulcer disease?