A higher area under the concentration-time curve/minimum inhibitory concentration target as a potential prognostic factor for vancomycin treatment of methicillin-resistant Staphylococcus aureus meningitis: A case report

The area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) – guided approach is recommended for vancomycin therapeutic drug monitoring in severe methicillin-resistant Staphylococcus aureus (MRSA) infection. However, evidence regarding the efficacy of vancomycin AUC-guided strategies for the treatment of systemic infections is limited. This case report describes the successful treatment of MRSA meningitis, with vancomycin using a higher AUC/MIC target. A 61-year-old woman who underwent ventriculoperitoneal (VP) shunt placement for subarachnoid hemorrhage, developed MRSA meningitis due to shunt infection. Vancomycin was administered intravenously, with concurrent monitoring of serum and cerebrospinal fluid (CSF) vancomycin concentrations and AUC/MIC. On post-operative day (POD) 24 of VP shunt placement, the vancomycin trough concentration and AUC/MIC were 12.0 μg/mL and 515, respectively, with persistently positive CSF culture. On POD 28, the trough concentration and AUC/MIC were 18.6 μg/mL and 610, respectively. There were no major adverse events, and CSF culture turned negative on POD 30. The vancomycin CSF-to-serum ratio was approximately 41 %. For patients with MRSA meningitis, we suggest an optimal therapeutic range with a vancomycin AUC/MIC target near the upper limit of the therapeutic window.