Emergency and Toxicologycommon
A 58-year-old man is brought to the emergency department after being found drowsy beside an empty bottle of methadone mixture. He has a respiratory rate of 7/min, pinpoint pupils and oxygen saturation of 94% while receiving oxygen; he responds to voice and has a pulse of 82/min. Two small intravenous doses of naloxone restore his respiratory rate, but hypoventilation recurs six minutes later. Which one of the following is the most appropriate next step?