A prospective cohort study was performed to determine the optimal dose of
vancomycin to maintain a serum trough concentration of at least 15 to 20 mg/l and to assess the efficacy of this target
vancomycin concentration in the treatment of methicillin-resistant Staphylococcus aureus
pneumonia.
Vancomycin pharmacokinetic parameters were estimated using a CAPSIL software program from serum concentrations of 141 patients with
pneumonia treated with
vancomycin, regardless of methicillin-resistant Staphylococcus aureus status, at a 28-bed medical intensive care unit.
Vancomycin trough concentrations and other pharmacokinetic parameters were compared between five groups of patients differing in their renal function: (1)
creatinine clearance > or =60 ml/minute, (2)
creatinine clearance 30 to 60 ml/minute, (3)
creatinine clearance <30 ml/minute, (4) on intermittent haemodialysis, and (5) on
continuous renal replacement therapy. More than 70% of patients failed to reach the recommended therapeutic serum trough concentrations: a higher dose of
vancomycin is necessary to maintain serum trough concentration at 15 to 20 mg/l, particularly in
critically ill patients with
creatinine clearance above 60 ml/minute and in those on intermittent haemodialysis. Among patients with methicillin-resistant Staphylococcus aureus
pneumonia, no significant differences were observed in the treatment success rate, length of intensive care unit stay, and intensive care unit mortality rate between patients with
vancomycin trough concentrations of >20 mg/l, 15 to 20 mg/l and <15 mg/l.