[Optimal vancomycin serum level in Staphylococcus aureus infections?].

Vancomycin is the cornerstone of therapy against methicillin-resistant Staphylococus aureus in both community and nosocomial-acquired infections. Because vancomycin is a concentration-independent or time-dependant antibiotic, most clinicians have abandoned the routine practice of determining peak serum concentrations to rely solely on monitoring serum concentrations. The so-called therapeutic range most often quoted for vancomycin was assessed for through serum concentrations of 5-10 mg/l. But prolonged exposure to serum concentration close to the MIC is associated with the emergence of resistance. More recent guidelines recommended vancomycin in concentrations of 15-20 mg/l for the treatment of severe Staphylococcus infections or in situations where vancomycin penetration is poor. However, because of the great variability of vancomycin MIC(S) (0,12-4 mg/l) of susceptible Staphylococcus strains, guidelines should recommend through serum concentrations of 5-10 times the MIC.