What is the treatment for meningitis?

Treatment of Bacterial Meningitis

Bacterial meningitis requires immediate antibiotic therapy within 1 hour of clinical suspicion, even before diagnostic confirmation, to reduce mortality and morbidity.

Initial Assessment and Management

When to Suspect Bacterial Meningitis

• Classic symptoms: fever, neck stiffness, altered mental status, and headache
• High index of suspicion needed for immunocompromised patients and the elderly who may present atypically

Diagnostic Approach

1. Blood cultures should be obtained before antibiotics
2. Lumbar puncture (LP) should be performed immediately unless contraindicated
3. CT scan before LP is only indicated if patient has 1:
   • Focal neurologic deficits (excluding cranial nerve palsies)
   • New-onset seizures
   • Severely altered mental status (Glasgow Coma Scale score <10)
   • Severely immunocompromised state

Critical Time Considerations

• Do not delay antibiotics for imaging or LP if bacterial meningitis is suspected
• Start antibiotics within 1 hour of presentation 1
• If LP is delayed, obtain blood cultures and start empiric antibiotics immediately 1
• CSF cultures remain positive in 73% of cases if LP is performed within 4 hours of antibiotic administration 2

Empiric Antibiotic Therapy

Adults < 60 years old 1:

• Ceftriaxone 2g IV q12h OR Cefotaxime 2g IV q6h

Adults ≥ 60 years old or immunocompromised 1:

• Ceftriaxone 2g IV q12h OR Cefotaxime 2g IV q6h
• PLUS Amoxicillin 2g IV q4h (to cover Listeria)

When to suspect penicillin-resistant pneumococci 1:

• Add Vancomycin 15-20 mg/kg IV q12h OR Rifampicin 600mg IV/PO q12h if:
  • Patient recently arrived from a country with high pneumococcal resistance
  • Local epidemiology suggests high resistance rates

Pediatric dosing 1, 3:

• For meningitis: Ceftriaxone 100 mg/kg/day (not to exceed 4g daily)
• Duration: 7-14 days depending on pathogen

Adjunctive Therapy

Dexamethasone

• Adults with suspected or proven pneumococcal meningitis 1:

  • Dexamethasone 0.15 mg/kg IV q6h for 2-4 days
  • First dose 10-20 minutes before or with first antibiotic dose
  • Benefits include reduced unfavorable outcomes (15% vs 25%) and mortality (7% vs 15%)

• Children with bacterial meningitis 1:

  • Dexamethasone 0.15 mg/kg IV q6h for 2-4 days
  • Most beneficial for H. influenzae type b meningitis

Pathogen-Specific Treatment and Duration

Streptococcus pneumoniae 1:

• Penicillin-sensitive (MIC ≤0.06 mg/L):
  • Benzylpenicillin 2.4g IV q4h OR
  • Ceftriaxone 2g IV q12h OR
  • Cefotaxime 2g IV q6h
• Duration: 10 days if stable; 14 days if slow response

Neisseria meningitidis 1:

• Ceftriaxone 2g IV q12h OR
• Cefotaxime 2g IV q6h OR
• Benzylpenicillin 2.4g IV q4h
• Duration: 5 days

Listeria monocytogenes 1:

• Amoxicillin 2g IV q4h
• Duration: 21 days

Haemophilus influenzae 1:

• Cefotaxime 2g IV q6h
• Duration: 10 days

Special Considerations

Penicillin and Cephalosporin-Resistant S. pneumoniae 1:

• Continue ceftriaxone/cefotaxime PLUS
• Vancomycin 15-20 mg/kg IV q12h (maintain trough levels 15-20 μg/mL) PLUS
• Rifampicin 600 mg IV/PO q12h
• Duration: 14 days

Viral Meningitis

• Supportive care with analgesia and fluids
• For suspected HSV encephalitis: IV aciclovir 1

Common Pitfalls to Avoid

1. Delaying antibiotics for imaging or LP - this increases mortality
2. Unnecessary CT scans before LP in patients without contraindications
3. Failure to consider Listeria in elderly or immunocompromised patients
4. Inadequate dosing of antibiotics for CNS penetration
5. Not adjusting therapy based on local resistance patterns

Bacterial meningitis remains a neurologic emergency with high mortality despite advances in treatment. Early recognition, prompt antibiotic administration, and appropriate adjunctive therapy are crucial for improving outcomes.