Drug interactions
Isavuconazonium + Posaconazole
Severity: Major
Isavuconazonium and Posaconazole: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Posaconazole may raise isavuconazole concentrations, increasing the risk of dose-related adverse effects such as hepatotoxicity. Combining two azole antifungals offers little benefit and adds toxicity.
What this interaction means in plain words
Isavuconazonium and Posaconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Isavuconazonium belongs to Anti Fungals; Posaconazole belongs to Anti Fungals.
Why it happens
Posaconazole inhibits CYP3A4, which metabolizes isavuconazole.
What to do
Avoid combined azole therapy unless specifically justified. If needed, monitor liver tests and isavuconazole adverse effects.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Other interactions of Isavuconazonium
- Amobarbital + Isavuconazonium Contraindicated
- Apalutamide + Isavuconazonium Contraindicated
- Carbamazepine + Isavuconazonium Contraindicated
- Cisapride + Isavuconazonium Contraindicated
- Efavirenz + Isavuconazonium Contraindicated
- Enzalutamide + Isavuconazonium Contraindicated
Frequently asked questions
Can I take Isavuconazonium with Posaconazole?
MediHelp rates the interaction as major. Isavuconazonium and Posaconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Posaconazole may raise isavuconazole concentrations, increasing the risk of dose-related adverse effects such as hepatotoxicity. Combining two azole antifungals offers little benefit and adds toxicity.
How serious is the interaction between Isavuconazonium and Posaconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combined azole therapy unless specifically justified. If needed, monitor liver tests and isavuconazole adverse effects.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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