What is the treatment for meningitis?

Treatment of Bacterial Meningitis

Bacterial meningitis is a neurological emergency requiring immediate empiric antibiotic therapy within 60 minutes of hospital arrival, even before lumbar puncture or imaging, as delays in treatment are strongly associated with death and poor neurological outcomes. 1

Immediate Management Algorithm

Time-Critical Actions (Within 60 Minutes)

• Draw blood cultures immediately upon suspicion of meningitis, but do not delay antibiotics waiting for results 1
• Administer empiric antibiotics within 1 hour of hospital presentation, regardless of whether lumbar puncture has been performed 1
• Perform lumbar puncture immediately unless contraindications are present 2, 1
• Give dexamethasone with or just before the first antibiotic dose in adults with suspected pneumococcal meningitis 1

When to Delay Lumbar Puncture

Perform cranial CT before lumbar puncture only if the patient has: 1, 3

• Focal neurologic deficits
• New-onset seizures
• Severely altered mental status (Glasgow Coma Scale <10)
• Severely immunocompromised state

Critical pitfall: If lumbar puncture is delayed for any reason, blood cultures must be obtained and empiric antibiotics plus dexamethasone must be started immediately before imaging or LP 2, 1

Empiric Antibiotic Regimens

Adults <60 Years

Ceftriaxone 2g IV every 12 hours PLUS vancomycin 15-20 mg/kg IV every 8-12 hours 1, 4

Adults ≥60 Years

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

• The addition of ampicillin in older adults covers Listeria monocytogenes, which has increased incidence in this age group 1, 5

Neonates <1 Month

Ampicillin 50 mg/kg IV every 6-8 hours PLUS cefotaxime 50 mg/kg IV every 6-8 hours 1

• Critical warning: Ceftriaxone is contraindicated in neonates ≤28 days due to risk of bilirubin encephalopathy and precipitation with calcium-containing solutions 4
• Administer IV doses over 60 minutes in neonates to reduce risk of bilirubin encephalopathy 4

Children 1 Month to 18 Years

Ceftriaxone 50 mg/kg IV every 12 hours PLUS vancomycin 10-15 mg/kg IV every 6 hours 1

Regions with High Pneumococcal Resistance

In areas where pneumococcal resistance to third-generation cephalosporins exceeds critical thresholds, add vancomycin or rifampicin to the empiric regimen 3

Adjunctive Dexamethasone Therapy

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 1

• The rationale is that subarachnoid space inflammation is a major contributor to morbidity and mortality, and attenuation of this response decreases cerebral edema, increased intracranial pressure, and neuronal injury 2
• Dexamethasone should also be administered in children with suspected S. pneumoniae or H. influenzae meningitis 5
• Timing is critical: Dexamethasone must be given with or before antibiotics to be effective 2, 1

Pathogen-Specific Definitive Therapy

Once culture and susceptibility results are available, narrow therapy to pathogen-specific regimens: 1

Streptococcus pneumoniae

• Ceftriaxone 2g IV every 12 hours for 10-14 days 1, 6
• Alternative: Benzylpenicillin 2.4g IV every 4 hours if susceptible 1
• Use the longer duration (14 days) if clinical response is delayed 6

Neisseria meningitidis

• Ceftriaxone 2g IV every 12 hours for 5-7 days 1, 6
• Alternative: Benzylpenicillin 2.4g IV every 4 hours if susceptible 1
• This is the shortest duration among bacterial causes 6

Listeria monocytogenes

• Ampicillin 2g IV every 4 hours for 21 days 1, 6
• Alternative: Co-trimoxazole 10-20 mg/kg IV in 4 divided doses 1
• The 21-day duration is required due to the intracellular nature of this pathogen 6
• Common pitfall: Listeria is frequently undertreated due to confusion with other bacterial causes—ensure the full 21-day course 6

Haemophilus influenzae

• Ceftriaxone or cefotaxime for 10 days 6, 7
• Third-generation cephalosporins are effective even against beta-lactamase producing strains 4

Staphylococcus aureus

• At least 14 days of therapy is recommended, though optimal duration is not well-established 6

Gram-Negative Bacilli (Enterobacteriaceae)

• 21 days of treatment for CSF/blood infections 6
• Aminoglycosides should be added, especially in infants <3 months 7

Culture-Negative Meningitis

When CSF is suggestive of bacterial meningitis but cultures and PCR remain negative, continue empiric treatment for at least 14 days 6

Special Situations

Penicillin Allergy

Chloramphenicol 25 mg/kg IV every 6 hours is the recommended alternative 1

Viral (VZV) Meningitis

Aciclovir 10-15 mg/kg IV every 8 hours for 10-14 days 1, 8

• Consider adding corticosteroids if a vasculitic component is suspected 1, 8
• For post-varicella meningitis with vasculitis, add prednisolone 60-80 mg daily for 3-5 days 8

Administration Considerations

• Ceftriaxone should be administered intravenously by infusion over 30 minutes in adults 4
• Do not use calcium-containing diluents (Ringer's solution, Hartmann's solution) with ceftriaxone due to precipitation risk 4
• Ceftriaxone and calcium-containing IV solutions must not be administered simultaneously via Y-site 4

Critical Pitfalls to Avoid

• Never delay antibiotics for imaging or lumbar puncture—bacterial meningitis is a neurological emergency where every hour counts 1, 9
• Do not shorten treatment duration based on early clinical improvement alone—complete the full pathogen-specific course 6
• Do not use short-course therapy (5-7 days) for pneumococcal meningitis—this requires 10-14 days minimum 6
• Do not forget ampicillin in adults ≥60 years—Listeria coverage is essential in this population 1
• Do not administer dexamethasone after antibiotics have been started—it must be given with or before the first dose to be effective 2, 1
• Ensure adequate treatment duration for Listeria (21 days)—this is frequently undertreated 6