Certified Gastroenterology RN Gastroenterology Pharmacology 3 — Questions and Answers
Question 1: Before starting azathioprine for Crohn's disease, which enzyme activity should be assessed?
- Thiopurine methyltransferase (TPMT) (Correct answer)
- CYP2C19
- Alkaline phosphatase
- Glucose-6-phosphate dehydrogenase
Correct answer: Thiopurine methyltransferase (TPMT)
Low TPMT activity causes accumulation of toxic thiopurine metabolites, increasing the risk of severe myelosuppression.
Question 2: A patient on vedolizumab asks how the drug works; the nurse explains it blocks which target?
- Alpha-4-beta-7 integrin on gut lymphocytes (Correct answer)
- Tumor necrosis factor-alpha
- Interleukin-6 receptors
- Histamine H2 receptors
Correct answer: Alpha-4-beta-7 integrin on gut lymphocytes
Vedolizumab is gut-selective, preventing alpha-4-beta-7 integrin-mediated lymphocyte migration into intestinal tissue.
Question 3: Which laboratory value must be monitored most closely in a patient receiving octreotide for a variceal bleed?
- Blood glucose (Correct answer)
- Serum calcium
- Uric acid
- Serum magnesium
Correct answer: Blood glucose
Octreotide suppresses insulin and glucagon secretion, causing hyperglycemia or hypoglycemia.
Question 4: A patient with ulcerative colitis on sulfasalazine should be advised to supplement which vitamin?
- Folic acid (Correct answer)
- Vitamin D
- Vitamin B6
- Vitamin A
Correct answer: Folic acid
Sulfasalazine inhibits intestinal folate absorption and metabolism, so daily folic acid supplementation is recommended.
Question 5: Which antiemetic works by blocking serotonin 5-HT3 receptors?
- Ondansetron (Correct answer)
- Promethazine
- Scopolamine
- Dronabinol
Correct answer: Ondansetron
Ondansetron blocks 5-HT3 receptors in the chemoreceptor trigger zone and vagal afferents to prevent nausea and vomiting.
Question 6: A nurse should hold pancrelipase and notify the provider if the patient reports taking the capsules in which way?
- Crushing and chewing the enteric-coated beads (Correct answer)
- Taking them with every meal and snack
- Swallowing them whole with water
- Taking them with applesauce
Correct answer: Crushing and chewing the enteric-coated beads
Crushing or chewing destroys the enteric coating, inactivating enzymes in gastric acid and irritating oral mucosa.
Question 7: Which medication is used to reverse the effects of opioid-induced constipation without crossing the blood-brain barrier?
- Methylnaltrexone (Correct answer)
- Naloxone IV
- Loperamide
- Alvimopan taken indefinitely
Correct answer: Methylnaltrexone
Methylnaltrexone is a peripherally acting mu-opioid receptor antagonist that relieves constipation without reversing central analgesia.
Certified Gastroenterology RN Gastroenterology Pharmacology 3
Before starting azathioprine for Crohn's disease, which enzyme activity should be assessed?