What is the treatment for meningitis?

Treatment of Bacterial Meningitis

Immediate empiric antibiotic therapy must be started within 1 hour of clinical suspicion of bacterial meningitis, even before diagnostic confirmation, to reduce mortality and improve outcomes. 1, 2

Initial Assessment and Diagnosis

• Perform blood cultures before starting antibiotics
• Lumbar puncture (LP) should be performed if no contraindications exist
• If LP must be delayed (due to contraindications requiring CT scan), start antibiotics immediately after blood cultures
• Contraindications to immediate LP (requiring CT first):
  • Focal neurologic deficits (excluding cranial nerve palsies)
  • New-onset seizures
  • Severely altered mental status (Glasgow Coma Scale score <10)
  • Severely immunocompromised state

Empiric Antibiotic Therapy

Adults <60 years:

• Ceftriaxone 2g IV q12h OR Cefotaxime 2g IV q6h
• PLUS Vancomycin 15-20 mg/kg IV q12h (if concern for penicillin-resistant pneumococci)

Adults ≥60 years or immunocompromised:

• Ceftriaxone 2g IV q12h OR Cefotaxime 2g IV q6h
• PLUS Vancomycin 15-20 mg/kg IV q12h
• PLUS Ampicillin 2g IV q4h (for Listeria coverage)

Adjunctive Therapy

• Dexamethasone 10mg IV q6h for 4 days, with first dose given before or with first antibiotic dose
• Particularly beneficial in pneumococcal meningitis (reduces mortality and unfavorable outcomes)
• Start before or simultaneously with antibiotics

Duration of Treatment (once pathogen identified)

• Neisseria meningitidis: 5 days
• Streptococcus pneumoniae (penicillin-sensitive): 10-14 days
• Streptococcus pneumoniae (resistant): 14 days
• Listeria monocytogenes: 21 days
• Haemophilus influenzae: 10 days

Pathogen-Specific Treatment

Streptococcus pneumoniae:

• If penicillin-sensitive (MIC ≤0.06 mg/L): Benzylpenicillin 2.4g IV q4h OR continue ceftriaxone/cefotaxime
• If penicillin-resistant but cephalosporin-sensitive: Continue ceftriaxone/cefotaxime
• If both penicillin and cephalosporin-resistant: Ceftriaxone/cefotaxime PLUS vancomycin PLUS rifampicin 600mg IV/PO q12h

Neisseria meningitidis:

• Continue ceftriaxone/cefotaxime OR benzylpenicillin 2.4g IV q4h
• If not treated with ceftriaxone, add single dose ciprofloxacin 500mg PO

Monitoring and Supportive Care

• Monitor for neurologic deterioration
• Maintain mean arterial pressure ≥65 mmHg
• Target euvolemia (avoid fluid restriction)
• Consider intubation for GCS <12
• Monitor for signs of increased intracranial pressure
• Provide antipyretics and analgesics as needed

Important Considerations

1. Time is critical: Each hour of delay in antibiotic administration worsens outcomes 1, 3, 4

2. Avoid unnecessary CT scans: Many patients receive unnecessary CT scans before LP, delaying treatment 5

3. Diagnostic yield: CSF cultures are positive in 73% of cases if LP is performed within 4 hours of starting antibiotics, but only 11% if performed later 5

4. Dexamethasone timing: Must be given before or with the first antibiotic dose to be effective 1, 2

5. Vancomycin considerations: When used, maintain serum trough concentrations of 15-20 mg/mL 1

Bacterial meningitis remains a medical emergency with high mortality despite advances in treatment. The most crucial factor in improving outcomes is rapid recognition and immediate initiation of appropriate antibiotic therapy.