A 25-year-old man is brought to the emergency department because of an overdose. He has central chest pain. He is diaphoretic, agitated, and confused. His temperature is 39 °C (102.2 °F), pulse is 130/min, and blood pressure is 180/90 mm Hg. Examination of the pupils show mydriasis with minimal reactivity to light. Tone is normal. There is no clonus but reflexes are brisk. Abdominal examination shows increased bowel sounds. An ECG shows ST elevations in leads V1-V4. Which of the following medications is the most likely cause of his presentation?