A 45-year-old man with known alcohol dependence presents to the Emergency Department confused, agitated, and tremulous. He reports his last alcoholic drink was 3 days ago. On examination, he has a heart rate of 120 bpm, BP 160/95 mmHg, temperature 37.9°C, and coarse tremor. He is disoriented to time and place and reports seeing insects on the walls. What is the most appropriate initial pharmacological management?