What is the recommended vancomycin dose for a patient with suspected or confirmed bacterial meningitis?

Vancomycin Dosing for Meningitis

For bacterial meningitis, administer vancomycin 15-20 mg/kg IV every 8-12 hours (not to exceed 2 g per dose) targeting trough concentrations of 15-20 mg/L, always in combination with ceftriaxone 2 g IV every 12 hours. 1, 2

When to Include Vancomycin in Empiric Meningitis Therapy

Add vancomycin to ceftriaxone empirically if:

• Recent travel to areas with high rates of penicillin-resistant Streptococcus pneumoniae 2, 3
• Local resistance rates to penicillin/cephalosporins are elevated 3
• Suspected or confirmed MRSA meningitis (post-neurosurgical, penetrating trauma, CSF shunt infection) 1, 2

Vancomycin should not be used as monotherapy for meningitis—always combine with a third-generation cephalosporin for empiric coverage. 2, 4

Specific Dosing Algorithm

Standard Dosing (Adults with Normal Renal Function)

• 15-20 mg/kg IV every 8-12 hours (actual body weight, maximum 2 g per dose) 1, 2
• For seriously ill patients with meningitis, consider a loading dose of 25-30 mg/kg (actual body weight) to rapidly achieve therapeutic levels 1
• Infuse loading doses over 2 hours with antihistamine premedication to minimize red man syndrome risk 1

Pediatric Dosing

• 15 mg/kg IV every 6 hours for children with serious invasive disease including meningitis 1, 2
• Target trough concentrations of 15-20 mg/L should be considered for serious CNS infections 1

Therapeutic Drug Monitoring

Obtain trough vancomycin levels before the fourth or fifth dose (at steady state). 1, 2

Target trough concentration: 15-20 mg/L for meningitis. 1, 2 This higher target (compared to 10-15 mg/L for other infections) is essential because vancomycin has poor CSF penetration even with inflamed meninges.

Monitor troughs in all meningitis patients—this is not optional. 1, 2 More frequent monitoring is required if renal function is unstable or fluctuating. 1

Dosing Adjustments Based on Troughs

• Trough <15 mg/L: Increase dose or decrease dosing interval
• Trough 15-20 mg/L: Continue current regimen
• Trough >20 mg/L: Decrease dose or increase dosing interval to avoid nephrotoxicity

Peak vancomycin concentrations are not recommended for monitoring. 1

Pathogen-Specific Considerations

Penicillin/Cephalosporin-Resistant S. pneumoniae

• Continue ceftriaxone 2 g IV every 12 hours PLUS vancomycin 15-20 mg/kg IV every 8-12 hours 2
• Consider adding rifampin 600 mg PO/IV twice daily for dual resistance 2
• Duration: 10-14 days (extend to 14 days for resistant strains) 2

MRSA Meningitis (Post-Neurosurgical, Shunt Infection)

• Vancomycin 15-20 mg/kg IV every 8-12 hours for 4-6 weeks 1
• Some experts add rifampin 600 mg daily or 300-450 mg twice daily for enhanced CNS penetration 1, 2
• Alternative if vancomycin fails: linezolid 600 mg PO/IV twice daily 1

Evidence Supporting High-Dose Regimens

A randomized trial demonstrated that high-dose vancomycin (compared to conventional dosing) in bacterial meningitis resulted in faster resolution of fever and leukocytosis, shorter hospitalization, and better Glasgow Coma Scale scores at day 10 without increased nephrotoxicity. 5 This supports the aggressive 15-20 mg/kg dosing with higher trough targets.

Critical Pitfalls to Avoid

Do not use vancomycin monotherapy for meningitis. Even for confirmed MRSA, vancomycin has suboptimal CSF penetration and should be combined with other agents or rifampin. 1, 2

Do not use standard 1 g every 12 hours dosing for meningitis. This dose is inadequate for CNS infections and will not achieve target troughs of 15-20 mg/L. 1

Do not delay vancomycin if indicated. If empiric vancomycin is warranted (resistant pneumococcus suspected, post-neurosurgical), it must be started within 1 hour of presentation alongside ceftriaxone. 3

Do not skip therapeutic drug monitoring. Trough monitoring is mandatory for all meningitis patients receiving vancomycin—failure to monitor risks treatment failure or nephrotoxicity. 1, 2

Consider alternative therapy if vancomycin MIC ≥2 mg/L. Target AUC/MIC ratios >400 may not be achievable with conventional dosing at these MICs. 2

Renal Function Monitoring

Monitor serum creatinine regularly during therapy. 2 Vancomycin-induced nephrotoxicity is defined as 2-3 consecutive increases in creatinine (≥0.5 mg/dL or ≥150% from baseline) after several days of therapy. 2

In patients with renal dysfunction or on dialysis, dosing must be adjusted based on creatinine clearance and trough levels, but the target trough of 15-20 mg/L remains the same for meningitis. 1