Scenario:
A 57‑year‑old woman with acute myeloid leukaemia is 7 days post‑induction chemotherapy. Her absolute neutrophil count is 80 cells/µL. She presents with a single episode of fever (38.6 °C) and mild malaise. There are no focal signs of infection on exam, and chest X‑ray is clear.
Question:
Which empiric IV antibiotic is most appropriate to cover her risk of Gram‑negative bacteraemia, including Pseudomonas?
A) Cefepime
B) Piperacillin–Tazobactam
C) Meropenem
D) Ceftazidime
E) Aztreonam
✅ Preferred Answer: A) Cefepime
📘 Mini‑Lesson & Explanation
Why Cefepime?
Broad Gram‑negative coverage including Pseudomonas aeruginosa
Reliable Gram‑positive activity against Streptococcus spp. and MSSA (No MRSA coverage —add vancomycin if needed)
Lower propensity to select for carbapenem‑resistant organisms compared with meropenem
Why Not Piperacillin–Tazobactam?
Also covers Pseudomonas, but its anaerobic spectrum is unnecessary in neutropenic fever without a clear source
Higher risk of Clostridioides difficile infection
May alter the gut microbiome more profoundly
Why Not Meropenem?
Excellent anti‑Pseudomonal and ESBL coverage, but
Reserve carbapenems for suspected resistant organisms or documented ESBL bacteremia to preserve efficacy and limit resistance
Why Not Ceftazidime?
Covers Pseudomonas well, but
Poor Streptococcal activity—leaving a gap against Gram‑positives common even in febrile neutropenia
Often requires combination with another agent for Gram‑positive coverage
Why Not Aztreonam?
Covers Pseudomonas and most Gram‑negatives, but
No Gram‑positive activity—would need a second agent (e.g. vancomycin) empirically
Typically reserved for patients with severe β‑lactam allergy
💡 Teaching Pearls
Febrile Neutropenia Protocols: First‑line monotherapy is an anti‑Pseudomonal β‑lactam with reliable Gram‑negative and some Gram‑positive coverage (cefepime, ceftazidime, piperacillin‑tazobactam, or a carbapenem).
Agent Selection: Choose the narrowest-spectrum agent that still covers P. aeruginosa; cefepime is often favoured unless local resistance patterns dictate otherwise.
Escalation & De‑escalation:
Escalate if fever persists after 48 hours or cultures grow resistant organisms.
De‑escalate based on culture results and clinical response to minimise collateral damage.
MRSA Coverage: Add vancomycin or linezolid only if there are signs of catheter‑related infection, skin/soft tissue infection, or known colonisation.
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