Ace the Antibacterials Exam 2026 – Boost Your ABX Knowledge and Outshine the Rest!

In hospital-acquired pneumonia, you start with an anti-pseudomonal beta-lactam to cover Pseudomonas and other Gram-negatives, but MRSA can also be a cause. To address MRSA, you add an MRSA-active agent such as vancomycin or linezolid because they reliably cover MRSA in the lungs. Vancomycin inhibits cell wall synthesis in MRSA and is commonly used with monitoring of drug levels, while linezolid has excellent lung penetration and is a strong alternative when vancomycin isn’t suitable. The other options don’t provide MRSA coverage: aztreonam targets Gram-negatives only, cefepime lacks reliable MRSA activity, and doxycycline isn’t considered dependable for MRSA coverage in severe hospital-acquired pneumonia.