A 71 year old man comes to the emergency depament because of blurry vision and blood tinged urine. He states that he has a long history of hypeension treated with a beta blocker, an ACE inhibitor and a calcium channel blocker. He repos that he has had 3 days of blurry vision and urine that is "cola" colored. The symptoms began when he ran out of his medications 3 days ago and he has "not had the time" to get the prescriptions refilled. His physical examination is remarkable for a blood pressure of 200/110 mmHg in both arms, and funduscopic examination showing flame hemorrhages and papilledema. Urinalysis shows red blood cells and some dysmorphic red blood cell casts. He has an abdominal bruit. Which of the following is the most appropriate next step in management?