GI GI Pharmacology and Medications

Question 1

Proton pump inhibitors (PPIs) work by irreversibly inhibiting which enzyme in gastric parietal cells?

Accepted Answer

H+/K+-ATPase (proton pump)

Answer

Carbonic anhydrase

Answer

Histamine H2 receptor

Answer

Gastrin receptor

Question 2

Mesalamine (5-ASA) is the first-line therapy for mild to moderate disease in which condition?

Accepted Answer

Ulcerative colitis

Answer

Crohn's disease of the small bowel

Answer

Microscopic colitis

Answer

Pouchitis after IPAA

Question 3

Which antibiotic regimen is currently recommended for first-line H. pylori eradication in the United States (clarithromycin-resistant regions)?

Accepted Answer

Bismuth quadruple therapy (PPI + bismuth + tetracycline + metronidazole) for 10–14 days

Answer

Amoxicillin + clarithromycin for 7 days

Answer

Metronidazole monotherapy for 14 days

Answer

Ciprofloxacin + metronidazole for 10 days

Question 4

Infliximab and adalimumab are anti-TNF agents used in IBD; which is administered as an intravenous infusion rather than subcutaneous injection?

Accepted Answer

Infliximab

Answer

Adalimumab

Answer

Certolizumab pegol

Answer

Golimumab

Question 5

Lactulose is used in the management of hepatic encephalopathy through which primary mechanism?

Accepted Answer

Acidifying the colon to trap ammonium and reduce bacterial ammonia production

Answer

Reducing intestinal transit time to decrease ammonia absorption

Answer

Increasing renal excretion of ammonia

Answer

Directly chelating ammonia in the portal circulation

Question 6

Ondansetron belongs to which drug class and acts by blocking which receptor to control nausea and vomiting?

Accepted Answer

5-HT3 antagonist; serotonin receptor

Answer

Antihistamine; H1 receptor

Answer

Dopamine antagonist; D2 receptor

Answer

NK1 antagonist; substance P receptor