Last reviewed: April 2026

Key points

  • Antifungal medicines can interact with other medicines, including inhalers, steroid tablets, blood thinners, heart medicines, cholesterol tablets, and some over-the-counter or herbal products.
  • The azole antifungals usually interact by affecting how the liver handles medicines.
  • Amphotericin B is different: its main interaction risks are more often linked to kidneys, potassium, magnesium, and infusion-related effects.
  • This page gives an overview. It does not list every interaction.
  • For a full medicine-by-medicine check, use the BNF interaction checker or ask a pharmacist or clinician.

Why interactions matter in aspergillosis

People with aspergillosis often take more than one medicine. This may include inhalers, steroid tablets, medicines for reflux, antibiotics, pain relief, blood pressure treatment, blood thinners, cholesterol tablets, and drugs for other long-term conditions. That means medicine checks are especially important whenever an antifungal is started, stopped, or changed.

How the main antifungals differ

Most long-term interaction questions in aspergillosis involve the azole antifungals: itraconazole, voriconazole, posaconazole, and isavuconazole. These mainly interact because they affect liver enzymes, especially CYP3A4, although some also affect CYP2C9 and CYP2C19.

Amphotericin B behaves differently. Its most important risks are usually kidney stress, low potassium, low magnesium, and additive toxicity with other medicines rather than classic liver-enzyme interactions.

Quick comparison table

Antifungal Main interaction pattern Typical complexity Important extra point
Itraconazole Strong enzyme-based interactions, especially CYP3A4 High Capsules and liquid are not handled by the body in the same way
Voriconazole Complex enzyme-based interactions involving several CYP pathways High More variable between patients; visual side effects and photosensitivity are well recognised
Posaconazole Mainly CYP3A4-related interactions Moderate Tablets and oral suspension are not interchangeable in the same way
Isavuconazole Mainly CYP3A4-related interactions, usually less complex than older azoles Lower to moderate Can shorten the QT interval
Amphotericin B Kidney, potassium, magnesium, and infusion-related interaction risks Different rather than simpler Formulations are not interchangeable

Individual antifungal guides

What patients should do in practice

  • Keep an up-to-date list of all medicines, including inhalers, creams, over-the-counter medicines, supplements, and herbal products.
  • Tell your doctor, nurse, pharmacist, or hospital team that you are taking an antifungal.
  • Do not start, stop, or swap medicines on your own because of something you have read online.
  • Ask specifically about new medicines, steroid changes, reflux treatment, blood thinners, cholesterol medicines, and heart medicines.

When to seek medical advice

Seek medical advice promptly if symptoms change after a medicine is started, stopped, or changed. Seek urgent help for severe bleeding, fainting, severe muscle pain, marked palpitations, rapidly worsening breathlessness, severe drowsiness, or a sudden significant decline in your health.

Important

This resource is educational. It does not replace personalised advice from your clinical team, GP, or pharmacist, and it is not a complete interaction database.

References

Path: Start » Treatment » Antifungals » Antifungal drug interactions: what patients with aspergillosis need to know

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