Bacterial Meningitis Treatment Guidelines

Immediate Management

The American College of Physicians recommends starting empiric antibiotic therapy immediately upon clinical suspicion of bacterial meningitis, within 1 hour of hospital arrival, even before lumbar puncture or imaging is performed, as delays in treatment are strongly associated with death and poor outcomes 1
Blood cultures should be drawn immediately upon suspicion of meningitis, and antibiotic administration should occur within 60 minutes of hospital presentation 1
The Infectious Diseases Society of America recommends that cranial CT should be performed before lumbar puncture only if the patient has focal neurologic deficits, new-onset seizures, severely altered mental status, or a severely immunocompromised state 1

For adults <60 years, the recommended empiric antibiotic regimen is ceftriaxone 2g IV every 12 hours, plus vancomycin 15-20 mg/kg IV every 8-12 hours 1, 2, 3
For adults ≥60 years, the recommended empiric antibiotic regimen is ceftriaxone 2g IV every 12 hours, plus vancomycin 15-20 mg/kg IV every 8-12 hours, plus ampicillin 2g IV every 4 hours 1, 2, 3
For neonates <1 month, the recommended empiric antibiotic regimen is ampicillin 50 mg/kg IV every 6-8 hours, plus cefotaxime 50 mg/kg IV every 6-8 hours 1
For children 1 month to 18 years, the recommended empiric antibiotic regimen is ceftriaxone 50 mg/kg IV every 12 hours, plus vancomycin 10-15 mg/kg IV every 6 hours 1

For Streptococcus pneumoniae, the recommended definitive therapy is ceftriaxone 2g IV every 12 hours for 10-14 days, with alternative regimens including benzylpenicillin 2.4g IV every 4 hours 2, 3
For Neisseria meningitidis, the recommended definitive therapy is ceftriaxone 2g IV every 12 hours for 5 days, with alternative regimens including benzylpenicillin 2.4g IV every 4 hours 2, 3
For Listeria monocytogenes, the recommended definitive therapy is ampicillin 2g IV every 4 hours for 21 days, with alternative regimens including co-trimoxazole 10-20 mg/kg IV in 4 divided doses 2

Dexamethasone 10 mg IV every 6 hours should be started with or just before the first antibiotic dose in adults with suspected pneumococcal meningitis, and continued for 4 days if pneumococcal meningitis is confirmed 4

For viral meningitis, the recommended treatment is aciclovir 10-15 mg/kg IV every 8 hours for 10-14 days, with consideration of adding corticosteroids if a vasculitic component is suspected 5
For penicillin allergy, the recommended alternative antibiotic is chloramphenicol 25 mg/kg IV every 6 hours 2, 3
For outpatient parenteral antibiotic therapy, the recommended regimen is ceftriaxone 2g IV twice daily initially, with consideration of switching to 4g IV once daily after the first 24 hours 4