A 19-year-old presents with fever, neck stiffness, and petechial rash. CSF shows: glucose 32 mg/dL (serum 92), protein 240 mg/dL, WBC 1800 cells/µL (90% neutrophils). Gram stain shows Gram-negative diplococci. What is the empiric antibiotic of choice and the most important adjunctive therapy?

• A Ampicillin + gentamicin; rifampicin
• B IV vancomycin + ceftriaxone; mannitol for raised ICP
• C IV ceftriaxone; dexamethasone before or with first antibiotic dose ✓
• D IV penicillin G; aspirin for antipyresis

Explanation

Gram-negative diplococci in CSF indicates Neisseria meningitidis meningococcal meningitis. IV ceftriaxone (or cefotaxime) is the antibiotic of choice. Adjunctive dexamethasone given before or simultaneously with the first antibiotic dose reduces meningeal inflammation, lowers risk of hearing loss, and improves outcomes in bacterial meningitis. Vancomycin is added for pneumococcal meningitis suspicion in areas with penicillin-resistant Streptococcus pneumoniae. Mannitol is not routinely used unless herniation is imminent.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.