Approach to medication exposure (pediatrics) Quiz: Ace Your Exams

A 6-year-old girl is brought to the emergency department after her parent found her in the bathroom with an open bottle of medication. Her parent states they briefly left the patient unattended, and upon returning, found the child difficult to wake and breathing abnormally. There is no history of trauma or recent illness, but the parent reports that the child's grandparent, who lives with them, takes several medications for chronic pain. The child has no significant past medical history. The patient’s temperature is 36.5°C (97.7°F), heart rate is 58/min, blood pressure is 85/50 mmHg, respiratory rate is 8/min, and oxygen saturation is 89% on room air. She is unresponsive to verbal stimuli but withdraws from painful stimuli. Pupils are bilaterally constricted to 2 mm and sluggishly reactive. Her respiratory effort is shallow, and there are decreased breath sounds bilaterally. Which of the following is the most likely cause of this patient’s current condition?