Empiric meningitis therapy in adults over 50 includes an agent to cover Listeria: which drug?

Prepare for the Antibacterials (ABX) Exam. Study with flashcards and multiple-choice questions, each question comes with hints and explanations. Get ready to ace your test!

Listeria coverage is essential in empiric meningitis therapy for adults over 50. Listeria monocytogenes becomes a more likely cause in this age group, so the regimen must include an agent active against it. Ampicillin provides reliable activity against Listeria and is added to empiric therapy to cover this organism. In practice, clinicians often combine a third-generation cephalosporin like ceftriaxone to cover the common pathogens (Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae) with ampicillin for Listeria. Vancomycin broadens coverage against penicillin-resistant pneumococcus but does not cover Listeria. Doxycycline is not used for meningitis due to poor central nervous system penetration and lack of reliable Listeria activity. So ampicillin is the drug needed to ensure Listeria coverage in adults over 50.