Review Question - QID 109621

A 27-year-old homeless man presents to the emergency department with abdominal pain and vomiting. He has a known history of intravenous drug use and has been admitted to the hospital several times before. On physical examination his temperature is 99°F (37.2°C), blood pressure is 130/85 mmHg, pulse is 90/min, respirations are 19/min, and pulse oximetry is 99% on room air. The patient is in obvious discomfort. There is increased salivation and lacrimation. Pupils are reactive to light and 5 mm bilaterally. Cardiopulmonary exam is unremarkable. There is diffuse abdominal tenderness to palpation with no rebound or guarding. Which of the following interventions would have prevented this patient’s current condition?