Ceftriaxone Dosing for Meningitis
For bacterial meningitis, the recommended dose of ceftriaxone is 2 grams IV every 12 hours (total 4 grams daily). 1, 2
Pathogen-Specific Dosing
- For pneumococcal meningitis, administer ceftriaxone 2g IV every 12 hours for 10-14 days, with treatment extension if the patient has not recovered by day 10 1, 2
- For meningococcal meningitis, administer ceftriaxone 2g IV every 12 hours for 5 days 1, 2
- For Haemophilus influenzae meningitis, administer ceftriaxone 2g IV every 12 hours for 10 days 1, 2
- For Enterobacteriaceae infections in CSF/blood, administer ceftriaxone 2g IV every 12 hours for 21 days 1
Special Considerations
- For patients with suspected penicillin-resistant pneumococci, add vancomycin 15-20 mg/kg IV twice daily or rifampicin 600 mg twice daily to the ceftriaxone regimen 1, 2
- For patients ≥60 years with suspected meningitis, add amoxicillin 2g IV every 4 hours to cover Listeria monocytogenes 1, 2
- In pediatric patients with meningitis, the recommended dose is 100 mg/kg/day (not to exceed 4 grams daily), which may be administered once daily or divided every 12 hours 3
- Treatment durations may need to be extended if the patient is not responding adequately to therapy 1
Administration Guidelines
- Administer intravenous doses over 30 minutes in adults 3
- In neonates, administer over 60 minutes to reduce the risk of bilirubin encephalopathy 3
- Do not use diluents containing calcium, such as Ringer's solution or Hartmann's solution, to reconstitute ceftriaxone 3
Pharmacokinetic Considerations
- Ceftriaxone penetrates well into the CSF, with mean trough levels of approximately 3.5 μg/mL 4
- The high CSF penetration allows for effective treatment of meningitis, with cerebrospinal fluid bactericidal titers typically 1:128 or higher 4
Emerging Evidence
- Recent research suggests that once-daily dosing (100 mg/kg/day) may achieve earlier pharmacodynamic targets compared to twice-daily dosing for common meningitis pathogens with MIC ≤1 mg/L 5
- However, current guidelines still recommend twice-daily dosing for meningitis to ensure adequate CSF concentrations throughout the treatment period 1, 2
- A 2023 study found no statistical difference in outcomes between once-daily (2g) and twice-daily (2g) ceftriaxone dosing regimens for penicillin-susceptible Streptococcus pneumoniae meningitis, suggesting that once-daily dosing may be sufficient for highly susceptible organisms 6
Common Pitfalls to Avoid
- Do not underdose ceftriaxone for meningitis; the standard dose for other infections (1-2g daily) is insufficient for CNS infections 2
- Do not delay treatment while waiting for culture results if bacterial meningitis is suspected 7
- Do not discontinue therapy prematurely, even if clinical improvement occurs rapidly 7
- For outpatient therapy of meningitis, ensure the patient has received at least 6 days of inpatient treatment, is afebrile for 24-48 hours, and is clinically improving 7