For bacterial meningitis in adults, which antibiotic is typically used as a first-line treatment?

Ceftriaxone is commonly utilized as a first-line antibiotic for bacterial meningitis in adults due to its broad-spectrum activity, particularly against the most prevalent pathogens associated with this condition, including Streptococcus pneumoniae and Neisseria meningitidis. It penetrates well into the central nervous system (CNS) and provides reliable coverage. The dosing schedule typically allows for ease of administration and effective therapeutic levels in the cerebrospinal fluid.

While Vancomycin is also critical, especially in areas with high rates of methicillin-resistant Staphylococcus aureus (MRSA), it is generally used in combination with ceftriaxone, rather than as a standalone first-line treatment. Ampicillin can be utilized in certain cases, particularly for coverage against Listeria monocytogenes, especially in specific populations such as the elderly or immunocompromised, but it is not typically used alone for the most common bacterial pathogens. Doxycycline, while effective for certain infections, does not provide adequate coverage for the primary organisms causing adult bacterial meningitis and is therefore not considered a first-line choice.