Loading
Some people on intensive chemotherapy, such as for acute leukaemia, are offered an antibiotic tablet while their white cells are lowest,. Guidelines disagree on who should have it: NICE offers it to more adults; children's and Australian guidelines limit it to the highest risk, as it breeds resistant germs. It does not replace calling the team at once with a fever.
Guidelines agree that prophylaxis is a fluoroquinolone given only for the period of severe neutropenia, and differ on who gets it. NICE CG151 offers fluoroquinolone prophylaxis to adults with acute leukaemias, stem cell transplants or solid tumours in whom a neutrophil count of 0.5 × 10⁹/L or lower is anticipated, noting that only ciprofloxacin was licensed for it in September 2024 and pointing to the MHRA January 2024 restrictions; units using it should monitor resistance. ASCO/IDSA (2018) recommend antibacterial prophylaxis for patients at high risk, including those expected to have profound, protracted neutropenia (under 100 neutrophils/µL for more than 7 days). For children, the international paediatric guideline (2020, endorsed by COG) says consider prophylaxis only in AML and relapsed ALL on intensive chemotherapy expected to cause neutrophils under 500/µL for at least 7 days (weak, high quality), not routinely in ALL induction or after autologous or allogeneic HSCT (weak), and not at all when severe neutropenia for 7 days is not expected (strong, moderate); levofloxacin is preferred (strong, moderate), ciprofloxacin an alternative with weaker gram-positive cover. Prophylaxis halved bacteraemia in children with AML or relapsed ALL but increased resistance and did not reduce overall mortality. The 2025 Australian and New Zealand consensus concludes that in most circumstances the harms outweigh the benefit.
Why: Prophylaxis helps only when neutrophils will be very low for long enough; for shorter, milder neutropenia it adds harm without benefit.
“Do not use systemic antibacterial prophylaxis for children whose therapy is not expected to result in severe neutropenia (absolute neutrophil count <500/μL) for at least 7 days.”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Strong recommendation, moderate-quality evidence
Why: NICE judged that preventing infections in this group outweighs the costs; other guidelines limit prophylaxis to people at higher risk (see variants).
Why: In these children prophylaxis halved bloodstream infections, but it also raised resistance and did not lower overall deaths, so the panel kept it to the highest-risk group.
“Consider systemic antibacterial prophylaxis administration in children with AML and relapsed ALL receiving intensive chemotherapy expected to result in severe neutropenia (absolute neutrophil count <500/μL) for at least 7 days.”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Weak recommendation, high-quality evidence
Why: Their baseline risk of bloodstream infection is lower, so the smaller benefit was judged not to outweigh the resistance it causes.
“We suggest that systemic antibacterial prophylaxis not be used routinely for children receiving induction chemotherapy for newly diagnosed ALL.”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Weak recommendation, low-quality evidence
Why: Levofloxacin was tested in the large paediatric trial and covers the streptococci that ciprofloxacin covers less well. The 2026 update kept this strong recommendation.
“Levofloxacin is the preferred agent if antibacterial prophylaxis is planned.”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Strong recommendation, moderate-quality evidence
Why: New in the 2026 update; the 2020 edition had named ciprofloxacin as the alternative, with weaker cover against streptococci.
“A new conditional recommendation was introduced to consider using no antibacterial prophylaxis in patients unable to receive levofloxacin.”
Pediatric Oncology Group of Ontario panel, Journal of Clinical Oncology 2026 · conditional (as described in the abstract)
Why: Fluoroquinolones can cause disabling and long-lasting side effects, such as tendon damage; knowing this, some families choose not to have prophylaxis.
“Patients and families should be informed about potential short- and long-term fluoroquinolone-related adverse effects prior to administration and this information may lead to some families choosing against prophylaxis.”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020
Why: Limiting the time on the antibiotic limits resistance and side effects; the trials gave it only during severe neutropenia.
“If antibacterial prophylaxis is planned, we suggest that administration be restricted to the expected period of severe neutropenia (absolute neutrophil count <500/μL).”
Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Weak recommendation, low-quality evidence
Why: Widespread prophylaxis can make the germs that cause infections resistant to the same drugs used to treat them.
“Rates of antibiotic resistance and infection patterns should be monitored in treatment facilities where patients are having fluoroquinolones for the prophylaxis of neutropenic sepsis.”
Why: Infections still happen on prophylaxis, and the first-hour fever pathway applies in full.
Common practice: Every guideline read assumes that febrile neutropenia on prophylaxis is managed as an emergency; none states it as a separate recommendation. The first-hour protocol covers it.
How care is usually carried out, read from the guidelines and standards cited. Your own team's protocol and their judgement come first; this page is for understanding it, not for doing it yourself.
Give a fluoroquinolone only to people expected to have severe, prolonged neutropenia, only for that period, with resistance monitored. The guidelines differ on who qualifies. NICE CG151 offers it to all adults with acute leukaemia, stem cell transplant or a solid tumour in whom neutrophils of 0.5 × 10⁹/L or lower are expected, and does not grade recommendations. ASCO/IDSA (2018) limit it to adults at high risk, including profound, protracted neutropenia (under 100/µL for more than 7 days). The paediatric guideline (2020, endorsed by COG; its 2026 update maintains these recommendations and adds a conditional recommendation to consider no prophylaxis where levofloxacin cannot be used) limits it to AML and relapsed ALL with neutrophils under 500/µL for at least 7 days (weak, high quality) and prefers levofloxacin (strong, moderate). The Australian and New Zealand consensus (2025) concludes that in most circumstances the harms of resistance, side effects and microbiome disruption outweigh a benefit that does not include lower mortality.
NICE 2012 · ASCO and IDSA, Journal of Clinical Oncology 2018 · Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 · Pediatric Oncology Group of Ontario panel, Journal of Clinical Oncology 2026 · Children's Oncology Group 2020 · Internal Medicine Journal (Australian and New Zealand consensus) 2025
Where it differs: Offers fluoroquinolone prophylaxis to any adult with acute leukaemia, stem cell transplant or a solid tumour in whom neutrophils of 0.5 × 10⁹/L or lower are anticipated, including solid tumour chemotherapy, rather than only profound and protracted neutropenia.
Evidence: NICE does not grade recommendations. It notes that in September 2024 only ciprofloxacin was licensed for this use and refers to the MHRA January 2024 advice on fluoroquinolone restrictions.
Where it differs: Recommends antibacterial prophylaxis for patients at high risk of infection, including those expected to have profound, protracted neutropenia, defined as fewer than 100 neutrophils/µL for more than 7 days, or other risk factors.
Evidence: Read as an abstract only; the grade is not given here.
Where it differs: The updated consensus for adults and children concludes that the potential harm of resistance, adverse effects and microbiome disruption outweighs the reduction in infection in most circumstances, given no mortality benefit and better sepsis pathways.
Evidence: Read as an abstract only; its specific recommendations and grades were not read.
Internal Medicine Journal (Australian and New Zealand consensus) 2025
| Recommendation | Grade, as printed | Source |
|---|---|---|
| Consider prophylaxis in children with AML or relapsed ALL with neutrophils under 500/µL for at least 7 days | Weak recommendation, high-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| No routine prophylaxis in induction for newly diagnosed ALL | Weak recommendation, low-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| No prophylaxis when severe neutropenia for 7 days is not expected | Strong recommendation, moderate-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| No routine prophylaxis for children having autologous HSCT “We suggest that systemic antibacterial prophylaxis not be used routinely for children undergoing autologous HSCT.” | Weak recommendation, moderate-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| No routine prophylaxis for children having allogeneic HSCT “We suggest that systemic antibacterial prophylaxis not be used routinely for children undergoing allogeneic HSCT.” | Weak recommendation, moderate-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| Levofloxacin preferred | Strong recommendation, moderate-quality evidence | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
| Effect of levofloxacin on bacteraemia in children with AML and relapsed ALL “Levofloxacin prophylaxis significantly reduced bacteremia in this group (RR, .50; 95% CI, .32–.78).” | RR 0.50, 95% CI 0.32 to 0.78 (trial result reported by the guideline) | Pediatric Oncology Group of Ontario panel (Lehrnbecher et al.), Clinical Infectious Diseases 2020 |
Shares Febrile neutropenia, Neutropenia, Autologous stem cell transplant (high-dose therapy), Allogeneic stem cell transplantation and the tags protocol, paediatric.
Shares Febrile neutropenia, Neutropenia, Allogeneic stem cell transplantation, American Society of Clinical Oncology (ASCO) and the tags protocol, paediatric.
Shares National Institute for Health and Care Excellence, Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Fever and neutropenia in children with cancer or after stem cell transplant, Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Autologous stem cell transplant (high-dose therapy), Allogeneic stem cell transplantation, American Society of Clinical Oncology (ASCO), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Suspected febrile neutropenia (neutropenic sepsis): the first hour, Febrile neutropenia, Neutropenia, Acute lymphoblastic leukaemia and the tag protocol.
Shares Autologous stem cell transplant (high-dose therapy), Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Suspected febrile neutropenia (neutropenic sepsis): the first hour, Febrile neutropenia, Neutropenia, National Institute for Health and Care Excellence and the tag protocol.