A 45-year-old man comes to the emergency department because of a 1-day history of black, tarry stools. He has also had upper abdominal pain that occurs immediately after eating. Three weeks ago, he developed lower back pain with stiffness and was started on naproxen and cyclobenzaprine. He has no prior medical conditions. He has an allergy to penicillin that causes a rash and pruritus. Upper gastrointestinal endoscopy reveals gastric mucosal erythema and erosions. Which of the following best explains this patient's current symptoms?

Question

A 45-year-old man comes to the emergency department because of a 1-day history of black, tarry stools. He has also had upper abdominal pain that occurs immediately after eating. Three weeks ago, he developed lower back pain with stiffness and was started on naproxen and cyclobenzaprine. He has no prior medical conditions.  He has an allergy to penicillin that causes a rash and pruritus.  Upper gastrointestinal endoscopy reveals gastric mucosal erythema and erosions.  Which of the following best explains this patient's current symptoms?

Quizplus · Accepted Answer

Eductional Objective: Most adverse drug reactions are predictable and due to known pharmacologic properties of the drug.  Unpredictable reactions are less common and are typically driven by patient-specific genetics (eg, enzyme deficiency, immunologic idiosyncrasy).

A 45-Year-Old Man Comes to the Emergency Department Because of a 1-Day