You are on scene with a 19 year old male complaining of general malaise and shortness of breath. He is sweaty, breathing very shallow, and has pinpoint pupils that are slow to react. Which of the following is most likely the cause of his signs and symptoms?
A. Narcotic overdose
B. Benzodiazepine overdose
C. Lithium overdose
D. Stimulant overdose
Answer: A