A mother witnessed her 4-year-old child ingest pills from an aspirin bottle left on the kitchen table. There were 10 (325 mg) tablets in the bottle at the time. She brings him directly to the emergency department where he is found to be diaphoretic and has vomited twice since he arrived. He complains of nausea and a ringing sound in his ears. Which of the following therapies is not appropriate in the early care of this child?