Empiric therapy for adults with suspected acute bacterial meningitis includes which regimen?

• A. Vancomycin plus ceftriaxone
• B. Ampicillin only
• C. Doxycycline
• D. Metronidazole

Answer: (A)

In adults with suspected acute bacterial meningitis, you need immediate empiric therapy that covers the most common meningitis pathogens: Streptococcus pneumoniae and Neisseria meningitidis, with added coverage for Listeria in older or immunocompromised patients. Vancomycin paired with a third-generation cephalosporin such as ceftriaxone provides that broad coverage, including penicillin-resistant pneumococcus and meningococcus. Ampicillin alone won’t address the typical pathogens in most adults, and doxycycline or metronidazole don’t reliably cover the main meningitis organisms. Therefore, vancomycin plus ceftriaxone is the appropriate empiric regimen.