1. A 58-year-old male with a history of chronic alcohol abuse presents with epigastric pain radiating to the back, nausea, and vomiting. Laboratory tests reveal elevated amylase and lipase levels. Which of the following is the most likely diagnosis? A. Acute pancreatitis B. Peptic ulcer disease C. Cholecystitis D. Hepatic cirrhosis Answer: A. Acute pancreatitis Rationale: The patient's symptoms and laboratory findings are indicative of acute pancreatitis, often associated with chronic alcohol abuse. 2. A patient is prescribed omeprazole for gastroesophageal reflux disease (GERD). Which of the following best describes the mechanism of action of omeprazole? A. H2 receptor antagonist B. Proton pump inhibitor C. Antacid D. Prokinetic agent Answer: B. Proton pump inhibitor Rationale: Omeprazole is a proton pump inhibitor that reduces stomach acid production by inhibiting the H+/K+ ATPase enzyme at the gastric parietal cells. 3. Which medication is considered first-line treatment for a patient diagnosed with Clostridium difficile infection? A. Metronidazole B. Vancomycin C. Rifaximin D. Fidaxomicin Answer: B. Vancomycin Rationale: Vancomycin is considered the first-line treatment for Clostridium difficile infection, especially in cases of severe infection. 4. A patient with irritable bowel syndrome (IBS) is experiencing severe diarrhea. Which of the following pharmacological treatments is most appropriate?