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 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; if imaging or contraindications delay LP, give antibiotics first 2

When to Obtain CT Before Lumbar Puncture

Cranial CT is indicated only for these specific findings 1, 2:

• Focal neurologic deficits
• New-onset seizures
• Severely altered mental status
• Severely immunocompromised state

Critical pitfall: Never delay antibiotics while waiting for imaging or LP—bacterial meningitis is a neurological emergency where mortality increases with each hour of treatment delay 2

Empiric Antibiotic Regimens (Age-Based)

Adults <60 Years

• Ceftriaxone 2g IV every 12 hours 1, 2, 3
• 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) 1, 2

Children (1 Month to 18 Years)

• Ceftriaxone 50 mg/kg IV every 12 hours (maximum 2g per dose) 1, 2, 3
• 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 3

Critical pitfall: Ceftriaxone is contraindicated in neonates receiving calcium-containing IV solutions due to precipitation risk 3

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

Pathogen-Specific Definitive Therapy (After Culture Results)

Streptococcus pneumoniae (Pneumococcal Meningitis)

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

Neisseria meningitidis (Meningococcal Meningitis)

• Ceftriaxone 2g IV every 12 hours for 5-7 days 1, 2, 4
• Alternative: Benzylpenicillin 2.4g IV every 4 hours 1
• Shorter duration than other bacterial causes 4

Listeria monocytogenes

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

Haemophilus influenzae

• Ceftriaxone 2g IV every 12 hours for 10 days 4

Staphylococcus aureus

• At least 14 days of therapy 4

Gram-Negative Bacilli (Enterobacteriaceae)

• 21 days of treatment 4

Culture-Negative Meningitis

• Continue empiric treatment for at least 14 days when CSF suggests bacterial meningitis but cultures/PCR remain negative 4

Special Situations

Penicillin Allergy

• Chloramphenicol 25 mg/kg IV every 6 hours 1

High Penicillin-Resistant Pneumococci Risk (Recent Travel)

• Add vancomycin 15-20 mg/kg IV every 12 hours OR rifampicin 600mg every 12 hours 2

Viral Meningitis (Suspected HSV Encephalitis)

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

Critical Pitfalls to Avoid

• Never shorten treatment duration based on early clinical improvement alone—complete the full pathogen-specific course 2, 4
• Do not use short-course therapy (5-7 days) for pneumococcal meningitis—requires 10-14 days minimum 4
• Ensure adequate 21-day treatment for Listeria—frequently undertreated 4
• Extend therapy if clinical response is delayed—standard durations assume appropriate clinical improvement 4
• Never delay antibiotics for lumbar puncture or imaging—every hour counts in this neurological emergency 2