Soru

A 52-year-old man is evaluated in the hospital on day 3 of admission for severe right lower extremity cellulitis and fever. On presentation to the emergency department, his temperature was $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$) and his blood pressure was $92/58\text{ mmHg}$. Blood cultures were drawn, and he was empirically started on intravenous vancomycin and piperacillin-tazobactam along with fluid resuscitation. Today, his temperature is $37.3^\circ\text{C}$ ($99.1^\circ\text{F}$), his blood pressure is $124/78\text{ mmHg}$, and the erythema and induration of his right leg have significantly decreased. The admission blood cultures are now growing *Staphylococcus aureus* in both sets. Susceptibility testing demonstrates that the organism is resistant to penicillin, but susceptible to oxacillin, cefazolin, and vancomycin. Which of the following is the most appropriate next step in this patient's pharmacotherapy?