An 86 year old female patient who was being treated with vancomycin  for a staph infection of a knee prosthesis. The usual dose of vancomycin is 500mg every 12 hr .Her weight was 64.3 kg, height 165 cm, with  UN stable  serum creatinine of 2.9 mg/dl.

What do you suggest to do for this patient?.

Does the patient immediately need a modified dose?​