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, or severe immunocompromise 1, 2, 3
• If lumbar puncture is delayed for any reason, start antibiotics first and perform LP afterward 2, 3

Empiric Antibiotic Regimens by Age

Adults <60 Years

• Ceftriaxone 2g IV every 12 hours PLUS vancomycin 15-20 mg/kg IV every 8-12 hours 1, 2
• This combination covers Streptococcus pneumoniae (including resistant strains), Neisseria meningitidis, and Haemophilus influenzae 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, 2
• The addition of ampicillin is essential to cover Listeria monocytogenes, which has increased incidence in this age group 1, 2

Children (1 Month to 18 Years)

• Ceftriaxone 50 mg/kg IV every 12 hours (max 2g per dose) PLUS vancomycin 10-15 mg/kg IV every 6 hours 1, 2
• For meningitis specifically, use ceftriaxone 100 mg/kg/day (not to exceed 4g daily) as initial dose, then continue at this higher dose 5

Neonates (<1 Month)

• Ampicillin 50 mg/kg IV every 6-8 hours PLUS cefotaxime 50 mg/kg IV every 6-8 hours 1
• Ceftriaxone is contraindicated in neonates due to risk of bilirubin encephalopathy and precipitation with calcium-containing solutions 5
• If ceftriaxone must be used, administer over 60 minutes (not 30 minutes) to reduce bilirubin encephalopathy risk 5

Adjunctive Dexamethasone Therapy

• Give 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 subarachnoid inflammation 2, 6

Pathogen-Specific Definitive Therapy (After Culture Results)

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 if MIC <0.5 mg/L 1, 8

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, 6

Listeria monocytogenes

• Ampicillin 2g IV every 4 hours for 21 days 1, 2, 7
• The 21-day duration is critical due to the intracellular nature of this pathogen 7
• Alternative: Co-trimoxazole 10-20 mg/kg IV in 4 divided doses 1
• This organism is frequently undertreated—do not shorten the 21-day course 7

Haemophilus influenzae

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

Staphylococcus aureus

• At least 14 days of therapy is recommended 7

Gram-Negative Bacilli (Enterobacteriaceae)

• 21 days of treatment for CSF/blood infections 7
• Add aminoglycosides, especially in neonates under 3 months 8

Culture-Negative Bacterial Meningitis

• Continue empiric treatment for at least 14 days if CSF is suggestive of bacterial meningitis but cultures and PCR remain negative 7

Special Situations

Penicillin Allergy

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

Penicillin-Resistant Pneumococci (High-Risk Regions)

• Add vancomycin 15-20 mg/kg IV every 12 hours OR rifampicin 600mg every 12 hours to the standard regimen 2
• Consider this in patients with recent travel to areas with high resistance rates 2

Viral Meningitis (Herpes Simplex Encephalitis)

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

Ceftriaxone Administration Precautions

• Do not use calcium-containing diluents (Ringer's, Hartmann's) as ceftriaxone-calcium precipitates can form 5
• Never administer simultaneously with calcium-containing IV solutions via Y-site 5
• In non-neonates, ceftriaxone and calcium solutions may be given sequentially if lines are thoroughly flushed 5
• Infuse over 30 minutes in adults and children; 60 minutes in neonates 5

Critical Pitfalls to Avoid

• Never delay antibiotics for lumbar puncture or imaging—bacterial meningitis is a neurological emergency where every hour counts 2, 3
• Do not 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—this requires 10-14 days minimum 7
• Ensure adequate 21-day treatment for Listeria—this is frequently undertreated due to confusion with other bacterial causes 7
• Do not forget to add ampicillin in adults ≥60 years—Listeria coverage is essential in this population 1, 2
• Extend therapy if clinical response is delayed—standard durations assume appropriate clinical improvement 7