1.
A 29-year-old man reports to a general practitioner complaining of nausea and vomiting, fatigue, confusion, and a "hazy feeling" in his head. The patient’s history reveals that he is an avid consumer of milk and cheese and a frequent user of over-the-counter (OTC) medications to treat heartburn and sour stomach. Laboratory investigations reveal a serum Ca2+ level of 12.3 mg/dL (normal: 8.4-10.2). The physician determines that the patient’s condition is resulting from his excessive use of OTC drugs. Which of the following types of drugs is the patient most likely suffering adverse effects to?
Correct Answer
A. Antacids
Explanation
A is the correct answer. The patient is most likely suffering from milk-alkali syndrome, which can result from excessive doses of sodium bicarbonate or calcium carbonate, especially if they are taken in conjunction with intake of calcium-containing dairy products.
2.
A 23-year-old woman suffering with chronic constipation begins self-medicating with a therapeutic agent that functions by absorbing water in the GI tract leading to the formation of a bulky emollient gel which promotes peristalsis. Which of the following drugs is the patient most likely using to treat her symptoms?
Correct Answer
D. Methylcellulose
Explanation
D is the correct answer. Methylcellulose is a bulk-forming laxative, a group of agents that possess this mechanism of action. Docusate is a stool surfactant agent (permits water and lipids to penetrate stool). Mineral oil is also a stool surfactant (lubricates fecal material, preventing water loss from the stool). Lactulose and balanced polyethylene glycol are osmotic laxatives (increase stool liquidity by increasing fecal fluid content). Senna is a stimulant laxative (directly stimulates ENS function). Lubiprostone stimulates type 2 chloride channels in the small intestine.
3.
A 38-year-old woman is scheduled to undergo a GI endoscopic procedure. The night before the patient is administered bisacodyl and another drug to promote complete colonic cleansing before the procedure is performed. Which of the following drugs was most likely the additional pharmacological agent given to this patient to facilitate this clinical outcome?
Correct Answer
F. Balanced polyethylene glycol
Explanation
F is the correct answer. Balanced polyethylene glycol is utilized for this clinical purpose, often in conjunction with bisacodyl.
4.
A 37-year-old woman recently diagnosed with irritable bowel syndrome complains to her gastroenterologist of nausea, bloating, pain, and frequent severe diarrhea that has proven to be unresponsive to the use of loperamide. The physician prescribes alosetron and it significantly reduces all of her IBS-related symptoms. Which of the following statements correctly identifies why alosetron is effective at reducing the patient’s incidence of diarrhea?
Correct Answer
B. Enteric cholinergic neuron 5-HT3-receptor inhibition
Explanation
B is the correct answer. Serotonin antagonism in the ENS by alosetron causes inhibition of colonic motility and increases total colonic transit time, thus making it effective at reducing diarrhea. It does the opposite of A, C, D, and F. Its central action is responsible for its ability to reduce the central response to visceral afferent stimulation.
5.
A 42-year-old man recently diagnosed with peptic ulcers and GERD has started self-medicating with ranitidine. What is the mechanism of action of this pharmacological agent?
Correct Answer
C. Competitive inhibition of histamine H2-receptors
Explanation
C is the correct answer. Ranitidine is a H2-receptor antagonist.
6.
36-year-old man reports to the emergency department with signs and symptoms consistent with a tuberculosis infection and laboratory investigations confirm this diagnosis. The patient had been successfully treated for tuberculosis in the past and was in a state of remission. Within the past three months, the man had been started on a new therapeutic agent for the treatment of his worsening Crohn disease. Which of the following drugs did the patient most likely just have added to his drug regimen?
Correct Answer
F. Infliximab
Explanation
F is the correct answer. While all immunosuppressive agents can theoretical predispose a patient to infection, infliximab appears to be one of the primary GI agents associated with the risk of the development of tuberculosis. This potential is so significant that all patients should be prescreened for tuberculosis using PPD testing, and those with a positive result should be put on prophylactic antituberculosis therapy when beginning treatment with infliximab.
7.
A 43-year-old woman is referred to a gastroenterologist by her primary care physician after she complains of burning stomach pain for 3 weeks accompanied by intermittent indigestion and bloating, and produces a negative guiaic test. The patient undergoes an upper endoscopy which reveals a 0.5 cm ulcer in the duodenal bulb without evidence of active bleeding. A biopsy of the area tests positive for Helicobacter pylori. The patient is started on a 14 day triple drug regimen consisting of clarithromycin, amoxicillin, and what other drug?
Correct Answer
F. Omeprazole
Explanation
F is the correct answer. The 14-day triple therapy regimen consists of clarithromycin, amoxicillin/metronidazole, and a proton pump inhibitor.
8.
A 55-year-old man suffering with severe Crohn disease is unresponsive to conventional therapy and is prescribed infliximab. After 4 weeks of therapy, the patient displays excellent symptomatic improvement. What is the mechanism of action of this agent?
Correct Answer
B. Neutralizing soluble and membrane-bound tumor necrosis factor
Explanation
B is the correct answer. Infliximab is a monoclonal antibody that binds and neutralizes both soluble and membrane-bound TNF molecules.
9.
A 47-year-old woman with a history of opioid dependence is prescribed loperamide to treat the frequent diarrhea associated with her chronic ulcerative colitis. Why is this drug a good choice in this patient?
Correct Answer
D. Displays poor distribution in the CNS
Explanation
D is the correct answer. Loperamide is an opioid, but displays poor distribution in the CNS. Thus, the risk of the patient becoming dependent on this agent is relatively low.
10.
A 46-year-old man undergoes Beger’s resection to remove the head of his pancreas in order to treat his worsening chronic pancreatitis. A nasoenteric feeding tube is temporarily inserted while the patient recovers in the hospital. In order to facilitate the advancement of the tube from the patient’s stomach into the duodenum, which of the following drugs was administered to the patient?
Correct Answer
A. Metoclopramide
Explanation
A is the correct answer. Metoclopramide is a prokinetic drug utilized for this clinical purpose.
11.
A 55-year-old man is brought to the emergency department because of significant hematemesis and passing of melena for the past 2 hrs. The patient’s wife reports that her
husband has no significant past medical history and that he has been a daily alcohol drinker for the past 15-years. Physical examination results include:
BP 78/40 mmHg
Pulse 110 bpm
Respirations 22/min
Chest/Cardiac Within normal limits
Abdomen Ascites, palpable spleen, normal bowel sounds
Laboratory work is performed with the following results:
Hgb 7 g/dL (normal 13.5-17.5)
Hct 27% (normal 41-53)
AST 160 U/L (normal 8-20)
ALT 250 U/L (normal 8-20)
Alkaline phosphatase 40 U/L (normal 20-70)
An ECG reveals sinus tachycardia. The patient is transfused with three units of whole blood and two units of fresh frozen plasma. Gastric lavage with saline was performed and gastric aspirate from the nasogastric tube was strongly positive for blood. The patient is prepped for immediate endoscopy in order to determine the source of the bleeding. In the meantime, the physician orders the parenteral administration of a drug that will help to treat the patient’s suspected condition. What is the mechanism of action of the pharmacological agent that was most likely administered to this patient?
Correct Answer
B. Stimulation of somatostatin receptors
Explanation
B is the correct answer. The patient is suffering from bleeding esophageal varices, which demands emergency therapy with octreotide. This drug functions as a somatostatin receptor agonist.
12.
A 24-year-old woman complains to her gastroenterologist of chronic constipation. The patient was diagnosed with IBS six months previously. The physician prescribes a drug that functions by stimulating the action of small intestine type 2 chloride channels. Which of the following agents was prescribed to the patient?
Correct Answer
D. Lubiprostone
Explanation
D is the correct answer. Lubiprostone is a laxative that utilizes this mechanism of action.
13.
A 55-year-old man with a history of gastric ulcer presents to the hospital with a persistent epigastric pain in spite of 12 weeks of ranitidine treatment. After an endoscopy which shows a
partially healed gastric ulcer, a diagnosis of refractory ulcer is made. Biopsy results are positive for Helicobacter pylori. Which of the following drug combination would represent the best treatment for this patient?
Correct Answer
E. Omeprazole, metronidazole, and clarithromycin
Explanation
E is the correct answer. The best drug regimens for treatment of H. pylori-associated ulcers are the combination of antibiotics with a proton pump inhibitor.
14.
A 61-year-old man comes to the hospital for evaluation of his continuing ulcers. He has been treated for one year for peptic ulcer and has not experienced relief, despite escalating doses of various H2-receptor antagonists. All routine laboratory tests are within normal limits except a serum gastrin level, which is 3240 pm/mL (normal 0-100). Radiographic and endoscopic studies demonstrate one gastric and two duodenal ulcers. A drug with which of the following mechanisms of action would be most appropriate for this patient?
Correct Answer
E. Inhibition of H+/K+ ATPase of gastric parietal cells
Explanation
E is the correct answer. Proton pump inhibitors are the current mainstay of treatment for peptic ulcer disease, and are an excellent choice in a patient who has not experienced relief using H2-receptor antagonists.
15.
A 75-year-old man with terminal metastatic lung cancer has been in the hospital for 4 months. Recently his renal function has deteriorated and now laboratory results show creatinine 5.5 mg/dL and BUN 45 mg/dL. Because of poor food intake, immobility, and requirement for opioid analgesia, the patient is severely constipated and needs daily laxative therapy. Which of the following would be a suitable laxative for this patient?
Correct Answer
A. Lactulose
Explanation
A is the correct answer. C and D are contraindicated because of potential adverse effects that they can cause in patients with renal impairment. B and E are not laxatives.
16.
A 55-year-old man ,suffering from type II diabetes for 15 years, presented with a 2-month history of nausea, postprandial fullness, and uncomfortable bloating, all of which are unrelieved by antacids. The patient also had manifestation of autonomic neuropathy (impotence and orthostatic hypotension). A preliminary diagnosis of diabetic gastroparesis was confirmed later by physical examination and lab results. Which of the following drugs would be suitable to treat this patient’s gastrointestinal symptoms?
Correct Answer
C. Metoclopramide
Explanation
C is the correct answer. Metoclopramide is a prokinetic drug that is indicated for the therapy of delayed gastric emptying resulting from diabetic gastroparesis.
17.
A 42-year-old man, who has been receiving his first course of chemotherapy for a non-Hodgkin’s lymphoma, still complains of recurrent nausea and vomiting despite an antiemetic medication with ondansetron, dexamethasone, and aprepitant. Which of the following drugs would be appropriate to add to the patient’s antiemetic regimen?
Correct Answer
D. Dronabinol
Explanation
D is the correct answer. The patient has failed to respond to a 5-HT3-receptor antagonist, a glucocorticoid, and a NK1-receptor antagonist. Dronabinol is indicated for the prevention of chemotherapy-induced nausea and vomiting.
18.
A 62-year-old man with newly diagnosed lung cancer is scheduled to receive his first course of chemotherapy. A prophylactic antiemetic medication is planned. A drug from which of the following classes would be most appropriate for this patient?
Correct Answer
A. Serotonergic antagonists
Explanation
A is the correct answer. Ondansetron and its family members are the primary go-to drugs for the prevention of acute chemotherapy-induced nausea and vomiting.
19.
A 44-year-old man has been recently diagnosed with a duodenal ulcer and an antiulcer treatment was prescribed. Four weeks into therapy the patient complained of difficulty in erection during sex. He also noticed a bilateral enlargement of his breast. Which of the
following drugs was most likely prescribed?
Correct Answer
D. Cimetidine
Explanation
D is the correct answer. Cimetidine has inhibitory action on the androgen receptor, which can lead to both impotence and gynecomastia in men.
20.
A 45-year-old man, recently diagnosed with duodenal ulcer, started a treatment with antacids and omeprazole. Which of the following statements best describes the mechanism of action of antacids in peptic ulcer disease?
Correct Answer
C. They react with hydrochloric acid to form a salt and water
Explanation
C is the correct answer. Antacids function as Brønsted bases by accepting the proton from gastric hydrochloric acid.
21.
A 67-year-old man comes to the clinic complaining of nervousness, anxiety, insomnia, palpitation, and stomach pain. He has been suffering from COPD for 15 years which is presently treated with inhaled albuterol and ipratropium, and oral theophylline. He told the attending physician that he recently started taking cimetidine for an acid stomach. Which of the following statements best describes the mechanism of the patient’s current complains?
Correct Answer
B. Cimetidine decreased the clearance of theopHylline
Explanation
B is the correct answer. Cimetidine is a potent inhibitor of the cytochrome P450 enzyme system, which can inhibit the metabolism of numerous drugs, including their metabolic clearance.
22.
A 25-year old female is planning to take a 2-week cruise aboard a small sailboat. She has a history of motion sickness. A drug from which of the following classes would be most appropriate to prevent nausea and vomiting in this patient?
Correct Answer
E. H1- receptor antagonists
Explanation
E is the correct answer. The 1st generation H1-receptor antagonists are the drugs of choice for the prevention and treatment of motion sickness.