Vancomycin Dosing for Acute Meningitis
The recommended dose of vancomycin for acute meningitis is 15-20 mg/kg IV every 12 hours, with dosage adjustments based on serum trough levels to maintain 15-20 μg/mL. 1, 2
Empiric Therapy for Meningitis
- For suspected bacterial meningitis, vancomycin should be added to the empiric regimen when penicillin-resistant pneumococci is a possibility at a dose of 15-20 mg/kg IV every 12 hours 1
- This is particularly important for patients who have recently traveled to regions with high rates of pneumococcal resistance 1
- Vancomycin should be used in combination with a third-generation cephalosporin (ceftriaxone 2g IV every 12 hours or cefotaxime 2g IV every 6 hours) 1, 3
Pathogen-Specific Therapy
Pneumococcal Meningitis
- For penicillin and cephalosporin-resistant Streptococcus pneumoniae, continue using ceftriaxone 2g IV every 12 hours or cefotaxime 2g IV every 6 hours plus vancomycin 15-20 mg/kg IV every 12 hours 1, 2
- Consider adding rifampin 600 mg orally/IV twice daily in cases of dual resistance 1
- Treatment duration should be 10-14 days for patients who have recovered by day 10, and extended to 14 days for those with penicillin or cephalosporin-resistant pneumococcal meningitis 1
Staphylococcal Meningitis (including MRSA)
- For methicillin-resistant Staphylococcus aureus meningitis, vancomycin at 15-20 mg/kg IV every 8-12 hours is recommended 1, 2
- Some experts recommend adding rifampin 600 mg daily or 300-450 mg twice daily to vancomycin for better CNS penetration 1, 2
Monitoring and Dosage Adjustments
- Regular monitoring of serum vancomycin trough levels is essential to maintain concentrations between 15-20 μg/mL 2, 4
- CSF penetration of vancomycin is approximately 30-50% with inflamed meninges, but can vary significantly between patients 5, 4
- Higher serum concentrations correlate with higher CSF concentrations (r=0.6; p=0.025), supporting the need for adequate dosing 4
- Recent studies show that with appropriate dosing, vancomycin can achieve therapeutic CSF levels of approximately 7-11 mg/L even when concomitant steroids are used 4, 6
Special Considerations
- Continuous infusion of vancomycin (50-60 mg/kg/day after a loading dose of 15 mg/kg) may be considered in critically ill patients to maintain consistent serum and CSF levels 5
- CSF penetration is significantly higher in patients with meningitis (CSF/serum ratio of 48%) compared to those without meningitis (18%) 5
- For post-neurosurgical meningitis, the same dosing regimen of vancomycin (15-20 mg/kg IV every 12 hours) is recommended 2
- Duration of therapy should be at least 10-14 days for uncomplicated cases with good clinical response 2
Clinical Pitfalls
- Inadequate dosing of vancomycin may lead to treatment failure, as demonstrated in early studies where 4 out of 11 patients experienced clinical failure despite initial improvement 7
- Dexamethasone administration does not significantly impair vancomycin penetration into CSF when appropriate doses are used 4
- Renal function should be monitored regularly as transient alterations can occur with vancomycin therapy 7
- CSF vancomycin levels do not appear to decrease with alleviation of meningeal inflammation, supporting consistent dosing throughout the treatment course 6