What is the treatment for meningitis?

Treatment for 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 is performed. 1

Immediate Management

• Start antibiotics within 1 hour of hospital presentation - delays in treatment are strongly associated with death and poor outcomes 1, 2
• Draw blood cultures immediately, but do not delay antibiotic administration while awaiting results 1, 2
• Perform lumbar puncture immediately if clinically safe; if delayed by imaging or contraindications, administer antibiotics first 3
• CT imaging before lumbar puncture is only indicated for focal neurologic deficits, new-onset seizures, severely altered mental status, or severely immunocompromised state 1

Empiric Antibiotic Regimens (Before Pathogen Identification)

Adults <60 Years

• Ceftriaxone 2g IV every 12 hours PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours 1, 3
• Alternative if penicillin allergy: Chloramphenicol 25 mg/kg IV every 6 hours 3, 2

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, 3
• The ampicillin addition covers Listeria monocytogenes, which is more common in this age group 3, 4

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

Neonates (<1 month)

• Ampicillin 50 mg/kg IV every 6-8 hours 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
• Ceftriaxone is contraindicated in neonates due to risk of calcium-ceftriaxone precipitation 5

Pathogen-Specific Definitive Therapy (After Identification)

Streptococcus pneumoniae (Pneumococcal Meningitis)

• Continue ceftriaxone 2g IV every 12 hours for 10-14 days 3, 6
• If penicillin-sensitive (MIC ≤0.06 mg/L): may switch to benzylpenicillin 2.4g IV every 4 hours 3
• If penicillin AND cephalosporin resistant: ceftriaxone 2g IV every 12 hours PLUS vancomycin 15-20 mg/kg IV every 12 hours PLUS rifampicin 600mg IV/oral every 12 hours 3
• Duration: 10 days if recovered by day 10; extend to 14 days if delayed recovery or resistant organism 3, 6

Neisseria meningitidis (Meningococcal Meningitis)

• Ceftriaxone 2g IV every 12 hours for 5-7 days 3, 2, 6
• Alternative: benzylpenicillin 2.4g IV every 4 hours 3, 2
• Critical: If benzylpenicillin is used instead of ceftriaxone, add ciprofloxacin 500mg oral single dose to eradicate throat carriage and prevent transmission 2
• Ceftriaxone is preferred because it reliably eradicates meningococcal carriage in the oropharynx 2

Listeria monocytogenes

• Ampicillin 2g IV every 4 hours for 21 days 1, 6, 4
• Alternative if penicillin allergy: co-trimoxazole 10-20 mg/kg IV in 4 divided doses for 21 days 1
• The 21-day duration is required due to the intracellular nature of this pathogen 6

Haemophilus influenzae

• Ceftriaxone 2g IV every 12 hours for 10 days 6
• Third-generation cephalosporins are preferred due to beta-lactamase production 5

Culture-Negative Bacterial Meningitis

• Continue empiric treatment for at least 14 days when CSF is suggestive of bacterial meningitis but cultures and PCR remain negative 6

Adjunctive Dexamethasone Therapy

• Dexamethasone 10mg IV every 6 hours should be started with or just before the first antibiotic dose in adults with suspected pneumococcal meningitis 1
• Continue for 4 days if pneumococcal meningitis is confirmed 1
• Dexamethasone reduces mortality and adverse neurologic outcomes in pneumococcal meningitis by attenuating the subarachnoid inflammatory response 3, 7
• For children with H. influenzae type B meningitis, dexamethasone 0.15 mg/kg every 6 hours for 2-4 days has confirmed benefit 3
• The benefit in children with pneumococcal meningitis remains controversial 7

Special Considerations for Penicillin-Resistant Pneumococci

• Add vancomycin 15-20 mg/kg IV every 12 hours OR rifampicin 600mg every 12 hours if the patient has recently traveled to countries with high rates of penicillin-resistant pneumococci 3
• Check current resistance patterns via European Centre for Disease Prevention and Control or WHO websites 3

Critical Pitfalls to Avoid

• Never delay antibiotics for lumbar puncture or imaging - bacterial meningitis is a neurological emergency where every hour counts 3, 1
• 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
• Ensure adequate 21-day treatment for Listeria - this is frequently undertreated due to confusion with other bacterial causes 6
• Do not use ceftriaxone in neonates due to risk of fatal calcium-ceftriaxone precipitation 5
• Always add ampicillin for patients ≥60 years to cover Listeria, which is more common in this age group 3, 1