skip to main content

Pseudomonas Pneumonia — SCE Infectious Diseases MCQ

Instant feedback + full explanation. One question, done properly.

HardRespiratory InfectionPseudomonas PneumoniaSCE Infectious Diseases

A 70-year-old man with COPD is admitted with type 2 respiratory failure requiring non-invasive ventilation. He has had two courses of oral steroids in the past month. Sputum culture grows Pseudomonas aeruginosa. He is allergic to penicillin (anaphylaxis). CRP is 180 mg/L. What is the most appropriate empirical IV antibiotic while awaiting sensitivities?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — IV Meropenem 1 g TDS

With true penicillin anaphylaxis, Piperacillin/Tazobactam and Co-amoxiclav are contraindicated. Cross-reactivity between penicillins and carbapenems is very low (<1%), making Meropenem acceptable in severe penicillin allergy with anaphylaxis in most guidelines. Ceftazidime has approximately 1–2% cross-reactivity with penicillins. For Pseudomonas coverage in this context, Meropenem is the safest choice with the broadest cover. Ciprofloxacin plus Gentamicin is an alternative but dual non-beta-lactam therapy is less effective for serious Pseudomonal infections.

Reference: NICE NG138 2023 – Pneumonia: antimicrobial prescribing; BSAC 2019 – Antimicrobial guidelines