Treatment Guidelines for Bacterial Meningitis
Bacterial meningitis requires immediate empirical antibiotic therapy with third-generation cephalosporins, with specific adjustments based on age, suspected pathogens, and local resistance patterns. 1
Empirical Antibiotic Therapy
Adults < 60 years
- First-line treatment: Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours 2
- Alternative: Chloramphenicol 25 mg/kg IV every 6 hours (if cephalosporin allergy) 2
Adults ≥ 60 years
- First-line treatment: Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours PLUS Amoxicillin 2g IV every 4 hours (to cover Listeria monocytogenes) 2, 1
- Alternative: Chloramphenicol 25 mg/kg IV every 6 hours AND Co-trimoxazole 10-20 mg/kg (of trimethoprim component) in four divided doses 2
Pediatric Patients
- For meningitis: 100 mg/kg/day of ceftriaxone (not exceeding 4g daily), administered once daily or in divided doses every 12 hours 3
- Duration: 7-14 days typically 1
Adjustments for Antimicrobial Resistance
Suspected Penicillin-Resistant Pneumococci
- Add Vancomycin 15-20 mg/kg IV twice daily (aim for trough levels 15-20 μg/mL) 2, 1
- OR add Rifampicin 600 mg twice daily 2
- Consider this approach if patient has recently traveled to areas with high pneumococcal resistance 2
Confirmed Pathogen-Specific Treatment
Pneumococcal Meningitis
- Penicillin-sensitive (MIC ≤ 0.06 mg/L): Continue ceftriaxone/cefotaxime OR switch to benzylpenicillin 2.4g IV every 4 hours 2
- Penicillin-resistant but cephalosporin-sensitive: Continue ceftriaxone/cefotaxime 2
- Penicillin and cephalosporin-resistant: Continue ceftriaxone/cefotaxime PLUS vancomycin AND rifampicin 2
- Duration: 10 days if recovered by day 10; 14 days if not recovered by day 10 or for resistant strains 2, 1
Meningococcal Meningitis
- Continue ceftriaxone/cefotaxime OR switch to benzylpenicillin 2.4g IV every 4 hours 2
- Duration: 5 days with clinical improvement 1
Adjunctive Therapy
Dexamethasone
- 10 mg IV every 6 hours for 4 days 1
- Should be started with or before the first dose of antibiotics 1
- Particularly beneficial for pneumococcal meningitis 2
Special Considerations
Administration
- Administer antibiotics as soon as possible after diagnosis is considered likely 2
- For ceftriaxone, intravenous administration should be over 30 minutes (60 minutes in neonates) 3
- Vancomycin should never be used alone due to concerns about CSF penetration, especially when dexamethasone is given 1
Monitoring
- Monitor for clinical improvement within 24-48 hours 1
- Assess renal function, electrolytes, and clinical response 1
- Consider repeat lumbar puncture in patients who have not responded clinically after 48 hours of appropriate antimicrobial therapy
Prophylaxis for Contacts
- Close contacts of patients with Neisseria meningitidis require prophylaxis 1
- Options include:
- Ciprofloxacin: single 500mg oral dose
- Ceftriaxone: single intramuscular dose
- Rifampicin: oral administration for 2 days 1
Common Pitfalls and Caveats
Delayed antibiotic administration: Bacterial meningitis is a neurological emergency - administer antibiotics immediately once diagnosis is suspected 2
Inadequate coverage for Listeria in older adults: Always add amoxicillin for patients ≥60 years 2, 1
Failure to consider resistant organisms: Add vancomycin when resistance is suspected, particularly with recent travel history to areas with high resistance rates 2
Inappropriate duration of therapy: Treatment duration varies by pathogen - ensure adequate length of treatment to prevent relapse 1
Neglecting adjunctive dexamethasone: Should be started with or before the first antibiotic dose to reduce inflammatory response and improve outcomes 2, 1
Inadequate assessment for complications: All patients should be evaluated for potential long-term sequelae, including hearing tests before discharge 1
Overlooking prophylaxis for contacts: Close contacts of meningococcal meningitis patients require prophylaxis due to high risk of secondary infection 1