What is the treatment for meningitis?

Treatment for Meningitis

Start empiric antibiotics immediately within 1 hour of hospital arrival upon clinical suspicion of bacterial meningitis—do not delay for lumbar puncture or imaging, as every hour of delay increases mortality and poor neurologic outcomes. 1, 2

Immediate Management Algorithm

Time-Critical Actions (Within 60 Minutes)

• Draw blood cultures immediately upon suspicion, but do not wait for results before starting antibiotics 1, 2
• Administer empiric antibiotics within 60 minutes of hospital presentation, even before diagnostic procedures 1, 2
• Perform lumbar puncture immediately if clinically safe—only delay for CT imaging if the patient has:
  • Focal neurologic deficits
  • New-onset seizures
  • Severely altered mental status
  • Severely immunocompromised state 1, 2

Critical pitfall: Never delay antibiotics while waiting for imaging or lumbar puncture—bacterial meningitis is a neurological emergency where every hour counts 2, 3, 4

Empiric Antibiotic Regimens (Start Before Pathogen Identified)

Adults <60 Years

• Ceftriaxone 2g IV every 12 hours 1, 2, 5
• PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours 1, 2

Adults ≥60 Years

• Ceftriaxone 2g IV every 12 hours 1, 2
• PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours 1, 2
• PLUS Ampicillin 2g IV every 4 hours (to cover Listeria monocytogenes, which is more common in elderly patients) 1, 2

Children (1 Month to 18 Years)

• Ceftriaxone 50 mg/kg IV every 12 hours (maximum 2g per dose) 1, 2, 5
• PLUS Vancomycin 10-15 mg/kg IV every 6 hours 1, 2

Neonates (<1 Month)

• Ampicillin 50 mg/kg IV every 6-8 hours 1
• PLUS Cefotaxime 50 mg/kg IV every 6-8 hours 1
• Administer IV doses over 60 minutes in neonates to reduce risk of bilirubin encephalopathy 5

Critical pitfall: Ceftriaxone is contraindicated in neonates receiving calcium-containing IV solutions due to risk of fatal precipitation 5

Adjunctive Dexamethasone Therapy

• Start dexamethasone 10mg IV every 6 hours with or just before the first antibiotic dose in adults with suspected pneumococcal meningitis 1, 2
• Continue for 4 days if pneumococcal meningitis is confirmed 1, 2
• Dexamethasone reduces mortality and adverse neurologic outcomes by attenuating the subarachnoid inflammatory response 2, 6

Pathogen-Specific Definitive Therapy (After Identification)

Streptococcus pneumoniae (Pneumococcal Meningitis)

• Ceftriaxone 2g IV every 12 hours for 10-14 days 1, 2, 7
• Use the longer duration (14 days) if clinical response is delayed 7
• Alternative: Benzylpenicillin 2.4g IV every 4 hours 1

Neisseria meningitidis (Meningococcal Meningitis)

• Ceftriaxone 2g IV every 12 hours for 5-7 days 1, 2, 7
• This is the shortest duration among bacterial causes 7
• Alternative: Benzylpenicillin 2.4g IV every 4 hours 1

Listeria monocytogenes

• Ampicillin 2g IV every 4 hours for 21 days 1, 2, 7
• Alternative: Co-trimoxazole 10-20 mg/kg IV in 4 divided doses 1
• Critical pitfall: This requires the longest duration (21 days) due to intracellular nature—frequently undertreated due to confusion with other bacterial causes 7

Haemophilus influenzae

• Ceftriaxone 2g IV every 12 hours for 10 days 7, 8

Gram-Negative Bacilli (Enterobacteriaceae)

• 21 days of treatment required for CSF/blood infections 7

Culture-Negative Bacterial Meningitis

• Continue empiric treatment for at least 14 days when CSF is suggestive but cultures and PCR remain negative 7

Special Situations

Penicillin Allergy

• Chloramphenicol 25 mg/kg IV every 6 hours as alternative 1

High Penicillin-Resistant Pneumococci Areas

• Add vancomycin 15-20 mg/kg IV every 12 hours OR rifampicin 600mg every 12 hours if recent travel to countries with high resistance rates 2, 6

Viral Meningitis (Herpes Simplex Encephalitis)

• Aciclovir 10-15 mg/kg IV every 8 hours for 10-14 days 1
• Consider adding corticosteroids if vasculitic component suspected 1

Administration Details

• Ceftriaxone should be infused over 30 minutes in adults 5
• Infuse over 60 minutes in neonates to reduce bilirubin encephalopathy risk 5
• Do not use calcium-containing diluents (Ringer's, Hartmann's) with ceftriaxone—can cause fatal precipitation 5
• Concentrations between 10-40 mg/mL are recommended for IV administration 5

Critical Pitfalls to Avoid

• Never shorten treatment duration based on early clinical improvement alone—complete the full pathogen-specific course 2, 7
• Do not use short-course therapy (5-7 days) for pneumococcal meningitis—requires minimum 10-14 days 7
• Ensure adequate 21-day duration for Listeria—most frequently undertreated 7
• Extend therapy if clinical response is delayed—standard durations assume appropriate improvement 7
• Never delay antibiotics beyond 3 hours from first medical contact, even if imaging or LP not yet performed 6, 4