Febrile neutropenia: antibiotics within 60 minutes.
A single fever plus an ANC under 500 is the whole trigger. The first-60-minute workup, antipseudomonal monotherapy, when vancomycin is actually indicated, and the common sources when the usual signs are blunted.
Reviewed June 2026 · verify against current guidelines
Corrected October 2026. This page now follows the IDSA 2010 and ASCO/IDSA 2018 wording on vancomycin indications, penicillin allergy, low-risk outpatient care, antifungals and stopping antibiotics. The slides were posted before these corrections. Work a patient in the febrile neutropenia tool.
Definition & Risk
Define it fast.
Diagnostic criteria
| Fever | Single oral ≥38.3°C (101°F), or ≥38.0°C (100.4°F) for 1 h |
|---|---|
| Neutropenia | ANC <500, or expected to fall below 500 within 48 h |
| Profound | ANC <100 (highest infection risk) |
Risk stratification
- High risk: prolonged (>7 d) profound neutropenia, instability, comorbidity.
- MASCC ≥21 flags low risk; CISNE refines apparently stable patients.
Febrile neutropenia is an emergency.
ANC absolute neutrophil countMASCC / CISNE febrile-neutropenia risk scores
Why The Source Hides
Few neutrophils, few signs.
Blunted inflammation
Without neutrophils there is little pus, often no infiltrate, and minimal exam findings. Fever may be the only clue, cultures are often negative, and no source is found in roughly half of episodes.
Common sources and organisms
| Bloodstream, line | Coag-negative staph, S. aureus, gram-negatives |
|---|---|
| Mucositis | Viridans group streptococci (can cause shock) |
| Gut, perianal | Enteric gram-negatives, anaerobes |
| Lungs | Bacteria; mold (Aspergillus) if prolonged |
| Prolonged FN | Candida, invasive mold |
Gram-positives are the most common isolates, but gram-negatives like Pseudomonas are the most lethal. That is why empiric therapy must cover Pseudomonas.
FN febrile neutropenia
First 60 Minutes
Cultures, then antibiotics.
Draw before the first dose, but don't delay it
- Two blood culture sets: peripheral plus every central line lumen.
- CBC with differential, CMP, lactate, urinalysis and culture.
- Chest imaging if respiratory signs; culture any symptomatic site.
- Exam skin, catheter site, mouth, perianal. No DRE, no rectal temps.
Antibiotics within 60 minutes of presentation. The clock starts at triage.
DRE digital rectal examCMP comprehensive metabolic panel
Empiric Antibiotics
Antipseudomonal monotherapy.
First-line (high risk, inpatient)
| Monotherapy | Cefepime, piperacillin-tazobactam, or a carbapenem (meropenem, imipenem) |
|---|---|
| Penicillin allergy | Most tolerate a cephalosporin such as cefepime (IDSA Rec 12). Immediate-type reaction (hives, bronchospasm, anaphylaxis): aztreonam + vancomycin, or ciprofloxacin + clindamycin; no ciprofloxacin after fluoroquinolone prophylaxis, and no aztreonam with prior ESBL. Work the allergy answer in the febrile neutropenia tool. |
| Aminoglycoside | Consider adding if unstable or resistant gram-negatives are suspected (IDSA B-III); routine addition is not beneficial (ASCO 2018) |
Add vancomycin only for
- Hemodynamic instability or severe sepsis.
- Suspected catheter or skin/soft-tissue infection.
- Pneumonia on imaging, or MRSA, VRE or penicillin-resistant pneumococcus colonization (VRE: linezolid or daptomycin instead).
- Gram-positive bacteria in a blood culture, before identification.
- Severe mucositis only with fluoroquinolone prophylaxis and ceftazidime as the empiric agent; cefepime, piperacillin-tazobactam and carbapenems cover viridans streptococci.
Vancomycin is not routine. Stop it at 48 h if no gram-positive organism. Tailor all choices to prior cultures and local resistance.
MRSA methicillin-resistant Staphylococcus aureus
Pitfalls & Disposition
Where teams slip.
- Delaying antibiotics for the workup or a risk score.
- Reflexive vancomycin: no survival benefit, drives resistance.
- Missing the source: lines, perianal, mucositis, skin.
- Fever persisting 4 to 7 days with neutropenia expected beyond 7 days: consider empiric antifungal therapy and a fungal workup (chest CT, galactomannan), or a pre-emptive approach if stable with a negative CT and serology (IDSA Recs 28-29).
- Unexplained fever: IDSA continues antibiotics until the ANC recovers; ECIL-4 allows stopping after 72 hours or more if stable and afebrile for 48 hours.
- Abdominal pain or diarrhea: think neutropenic enterocolitis (CT; anaerobic cover with piperacillin-tazobactam, a carbapenem, or cefepime plus metronidazole) and send a C. difficile toxin assay.
- Steroids can blunt fever; trust vitals and exam even if afebrile.
Low risk means MASCC 21 or more (CISNE 0 to 2 if a stable solid tumor), no ASCO exclusion criteria, a caregiver, phone and transport around the clock, and within 1 hour of the hospital. Give the first dose in clinic or the ED and observe for at least 4 hours, then oral ciprofloxacin or levofloxacin plus amoxicillin-clavulanate (clindamycin if penicillin-allergic). Not after fluoroquinolone prophylaxis (IDSA 14ii; ASCO 2018).
Sources
Verify against current guidelines and local protocol before acting.
- Freifeld AG et al. Clinical Practice Guideline for the Use of Antimicrobial Agents in Neutropenic Patients with Cancer: 2010 Update by the IDSA. Clin Infect Dis 2011;52:e56-e93.
- NCCN Clinical Practice Guidelines in Oncology. Prevention and Treatment of Cancer-Related Infections, Version 1.2025.
- Taplitz RA et al. Outpatient Management of Fever and Neutropenia in Adults Treated for Malignancy: ASCO/IDSA Guideline Update. J Clin Oncol 2018;36:1443-1453.
- Klastersky J et al. The MASCC risk index: identification of low-risk febrile neutropenic patients. J Clin Oncol 2000;18:3038-3051.
- Carmona-Bayonas A et al. CISNE: clinical index of stable febrile neutropenia. J Clin Oncol 2015;33:465-471.
- Wingard JR. Overview of neutropenic fever syndromes. UpToDate; literature review through May 2026, topic updated Apr 2026.
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