Vancomycin Dosing for Acute Meningitis
For acute bacterial meningitis, vancomycin should be dosed at 15-20 mg/kg IV every 8-12 hours, with target trough serum concentrations of 15-20 mg/L. 1, 2
Indications for Vancomycin in Meningitis
- Vancomycin is indicated as part of empiric therapy when penicillin-resistant pneumococci is suspected or for confirmed cases of resistant pneumococcal or staphylococcal meningitis 1, 2
- It should be used in combination with a third-generation cephalosporin (ceftriaxone or cefotaxime) for empiric therapy of suspected bacterial meningitis 2
- For penicillin and cephalosporin non-susceptible Streptococcus pneumoniae, vancomycin should be added to the treatment regimen 1
Dosing Recommendations
- Initial dosing: 15-20 mg/kg IV every 8-12 hours for adults 1, 2
- Pediatric dosing: 15 mg/kg IV every 6 hours 1
- Adjust dosing based on renal function using the formula: daily dose (mg) = 15 × glomerular filtration rate (mL/min) 3
- Each dose should be administered over at least 60 minutes to minimize infusion-related reactions 3
Therapeutic Monitoring
- Obtain trough serum vancomycin concentrations just before the fourth dose (at steady state) 1
- Target trough serum concentrations of 15-20 mg/L for meningitis to ensure adequate CNS penetration 1, 2
- More frequent monitoring is recommended in patients with unstable renal function 1, 3
- CSF penetration is improved with meningeal inflammation, with penetration ratios of approximately 48% in bacterial meningitis 4, 5
Special Considerations
- Some experts recommend adding rifampin 600 mg daily or 300-450 mg twice daily to vancomycin for better CNS penetration in staphylococcal meningitis 1, 2
- Higher vancomycin doses may be required to achieve therapeutic CSF levels, as conventional dosing may result in subtherapeutic CSF concentrations 6, 5
- Consider alternative therapy if the vancomycin MIC is ≥2 mg/L, as target AUC/MIC ratios >400 may not be achievable with conventional dosing 1
Duration of Therapy
- For pneumococcal meningitis: 10-14 days 1
- For staphylococcal meningitis: 14 days 1
- Treatment duration may need to be extended if clinical response is delayed 1
Monitoring for Adverse Effects
- Monitor renal function regularly during therapy 1, 3
- Vancomycin-induced nephrotoxicity is defined as multiple (at least 2-3 consecutive) increases in serum creatinine (increase of 0.5 mg/dL or 150% increase from baseline) after several days of therapy 1
- High-dose vancomycin regimens for meningitis have not shown significantly increased nephrotoxicity compared to conventional dosing 6
Pitfalls and Caveats
- Vancomycin has poor blood-brain barrier penetration in the absence of meningeal inflammation 7
- CSF concentrations may be subtherapeutic in healthcare-associated meningitis with mild inflammation 7
- Continuous infusion of vancomycin (50-60 mg/kg/day after a loading dose of 15 mg/kg) may be considered to maintain consistent therapeutic levels 4
- Early clinical failures with vancomycin monotherapy have been reported in pneumococcal meningitis, supporting the recommendation for combination therapy 8