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Treatment and the treatment process

Antifungal medicines

During prolonged neutropenia, fungal infections — especially moulds — can be severe. Antifungal medicines prevent and treat them.

Last updated: ~2 min read
Glowing mould spores on a dark navy background deflected by a teal shield around the lungs.
Figure 1.Prevention protects against mould spores in the air.

01Short answer

Fungi are everywhere: the yeast Candida lives on the skin and in the gut, and spores of the mould Aspergillus float in the air. Healthy immunity keeps them in check easily, but during the long neutropenia after intensive acute leukemia treatment or allogeneic transplant they can cause serious infection of the lungs, sinuses or blood. So in high-risk periods a preventive medicine — such as posaconazole or fluconazole — is often given. If infection is suspected, a galactomannan blood test and a chest CT are done, and voriconazole, isavuconazole, lipid amphotericin B or echinocandins are used for treatment. The doctor chooses the medicine and duration according to the protocol.

02Simple explanation

Fungi are everywhere. Usually immunity keeps them in check.

Weak defences. In long neutropenia a fungal infection can be dangerous.

Protection. At high risk a preventive medicine is given.

Treatment. If suspected, special tests and strong medicines are used.

03Scientific explanation

Prophylaxis: during AML/MDS induction and in GVHD after transplant, posaconazole reduces invasive mould infections (IDSA, ECIL, NCCN guidance); fluconazole covers Candida only.

Mechanism: azoles block ergosterol synthesis in the fungal membrane (CYP51); amphotericin B binds ergosterol and forms pores; echinocandins (caspofungin, micafungin, anidulafungin) stop β-glucan synthesis in the cell wall.

Interactions and monitoring: azoles inhibit CYP3A4, so doses of venetoclax, vinca alkaloids and some TKIs are adjusted or the drug is changed; for voriconazole and posaconazole, blood levels (TDM), liver tests and the QT interval on ECG are monitored.

04What happens in the body?

Why prevention?

A mould infection gives few signs early on but can spread quickly. So in the highest-risk period — long neutropenia or after transplant — giving a medicine in advance is safer.

How do they work?

A fungal cell has a special wall and membrane that human cells lack. Antifungals target exactly these parts, weakening or killing the fungus.

A round fungal cell on a dark background whose wall is held by small golden locks.
Figure 2.An antifungal targets the fungal wall.

How is it found?

If a lasting fever does not respond to antibiotics, the doctor may check fungal markers in the blood, order a chest CT and sometimes a bronchoscopy.

A modern CT scanner in a calm hospital room in teal light.
Figure 3.When fungus is suspected, a chest CT is done.

05Protecting against fungi

A simplified outline.

Risk assessed — Length of neutropenia, transplant.1Risk assessedLength of neutropenia, transplant.
Prevention — A daily medicine.2PreventionA daily medicine.
Monitoring — Levels, liver, ECG.3MonitoringLevels, liver, ECG.
Treatment — If suspected — tests and a strong medicine.4TreatmentIf suspected — tests and a strong medicine.
Preventing infectionMoulds and yeasts.
InteractionsChecked by doctor and pharmacist.
Early detectionGalactomannan, CT.

06Antifungal medicines in leukemia

GroupExamplesMain use
AzolesFluconazolePreventing Candida
AzolesPosaconazolePreventing mould infection
AzolesVoriconazole, isavuconazoleTreating aspergillosis
PolyenesLipid amphotericin BSevere infection, mucormycosis
EchinocandinsCaspofungin, micafunginCandida bloodstream infection, empirical therapy

* The protocol and your doctor decide the medicine, form and duration.

07Key terms

Antifungal
A medicine against fungi.
Aspergillosis
Infection caused by the mould Aspergillus.
Candidiasis
Infection with the yeast Candida.
Galactomannan
A marker of Aspergillus found in the blood.
Azoles
A drug group that blocks ergosterol synthesis.
TDM
Measuring a drug’s level in the blood.

08Key points

  • Fungal infection is dangerous in long neutropenia.
  • Preventive medicine is given at high risk.
  • Azoles interact with many medicines.
  • Drug levels and the liver are monitored.
  • If suspected, CT and blood tests are done.
  • At home, keep away from mould sources.

09Frequently asked questions

How should I take posaconazole?

Your doctor and pharmacist explain how to take it (for example, with food); follow the instructions.

Can my vision change on voriconazole?

Brief visual changes and sun sensitivity sometimes occur; protect yourself from the sun and tell your doctor.

How do I protect myself from fungi at home?

Avoid soil, compost, building dust and mouldy places; your team will give exact advice.

How long does prevention last?

Usually until recovery from neutropenia or until immunity is strong enough — your doctor decides.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. How should I take posaconazole?

  2. Can my vision change on voriconazole?

  3. How do I protect myself from fungi at home?

  4. How long does prevention last?

My questions

12Sources

  1. National Cancer Institute (NCI). Chemotherapy to Treat Cancer
  2. Cancer Research UK. Chemotherapy
  3. National Cancer Institute (NCI). Infection and Neutropenia during Cancer Treatment
  4. MedlinePlus. Posaconazole
  5. MedlinePlus. Voriconazole
  6. NHS. Aspergillosis
  7. MedlinePlus. Aspartate aminotransferase (AST) blood test
  8. Canadian Cancer Society. Heart problems
  9. MedlinePlus. Electrocardiogram
  10. European Society of Cardiology (ESC). 2022 ESC Guidelines on cardio-oncology
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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