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

PPIs covalently and irreversibly bind the H+/K+-ATPase enzyme, blocking the final step of acid secretion in parietal cells.

Question 2

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

Accepted Answer

Ulcerative colitis

Answer

Mesalamine is the cornerstone of induction and maintenance therapy for mild-to-moderate ulcerative colitis due to its topical anti-inflammatory effect on the colonic mucosa.

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

Due to rising clarithromycin resistance, bismuth quadruple therapy for 10–14 days is recommended as first-line H. pylori treatment in most US regions.

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

Infliximab is a chimeric monoclonal antibody administered by IV infusion, whereas adalimumab and other anti-TNF agents are given subcutaneously.

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

Lactulose is metabolized by colonic bacteria to lactic and acetic acids, lowering pH and converting NH3 to NH4+, which is poorly absorbed and excreted in stool.

Gastrointestinal GI Practice Practice Test

Gastrointestinal GI Practice Practice Test

GI GI Pharmacology and Medications