What is the most appropriate treatment regimen for a 70-year-old female patient with Streptococcus pneumoniae (S. pneumoniae) meningitis and improving clinical condition?

Treatment of Penicillin-Sensitive Pneumococcal Meningitis

IV ceftriaxone and IV dexamethasone is the most appropriate treatment regimen for this 70-year-old female patient with penicillin-sensitive Streptococcus pneumoniae meningitis. 1

Rationale for Treatment Selection

Antibiotic Selection

• The patient has confirmed S. pneumoniae meningitis with a penicillin MIC of ≤0.12 mg/L, indicating penicillin sensitivity

• For penicillin-sensitive pneumococcal meningitis (MIC ≤0.06 mg/L), the UK Joint Specialist Societies guideline recommends any of the following options:

  • IV benzylpenicillin 2.4 g 4 hourly
  • IV ceftriaxone 2 g 12 hourly
  • IV cefotaxime 2 g 6 hourly 1

• Ceftriaxone is preferred over penicillin VK (oral) because:

  • Intravenous administration ensures reliable drug delivery and CNS penetration
  • Oral penicillin VK would not achieve adequate CSF concentrations needed for meningitis treatment 2
  • The patient is still in the ICU with improving but not fully resolved condition

De-escalation of Therapy

• The patient was initially on empiric therapy with:

  • IV vancomycin
  • IV ceftriaxone
  • IV ampicillin
  • IV acyclovir
  • IV dexamethasone

• De-escalation is appropriate now because:

  • S. pneumoniae has been identified as the causative organism
  • Susceptibility testing confirms penicillin sensitivity (MIC ≤0.12 mg/L)
  • Viral PCR tests are negative, eliminating need for acyclovir
  • No evidence of Listeria, eliminating need for ampicillin
  • No need for vancomycin as the organism is penicillin-sensitive 1, 3

Continued Dexamethasone Therapy

• Dexamethasone should be continued for a total of 4 days in confirmed pneumococcal meningitis 1, 3
• Dexamethasone reduces inflammatory response and improves outcomes in pneumococcal meningitis when started before or with antibiotics 3

Treatment Duration

• For patients with confirmed pneumococcal meningitis who have recovered by day 10, treatment should be stopped 1
• If not recovered by day 10, extend treatment to 14 days 1

Monitoring and Follow-up

• Continue to monitor neurological status and clinical improvement
• Repeat CSF analysis is not routinely required if clinical improvement occurs
• Watch for potential complications such as seizures, hydrocephalus, or cerebral edema

Common Pitfalls to Avoid

1. Switching to oral antibiotics too early (inadequate CSF penetration)
2. Discontinuing dexamethasone prematurely (should complete full 4-day course)
3. Using linezolid when not indicated (unnecessary for penicillin-sensitive pneumococci)
4. Using cefepime when ceftriaxone is appropriate and has proven efficacy
5. Stopping antibiotics too early (minimum 10-day course for pneumococcal meningitis)

By continuing IV ceftriaxone and IV dexamethasone, you are providing optimal therapy for this patient with penicillin-sensitive pneumococcal meningitis while appropriately de-escalating from the initial broad-spectrum regimen.