Drug interactions
Posaconazole + Voriconazole
Severity: Major
Posaconazole and Voriconazole: 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
Two azole antifungals given together offer no clear benefit and may increase adverse effects such as QT prolongation, hepatotoxicity and visual disturbances. Both are CYP3A4 inhibitors and voriconazole is also a substrate, so exposure may change unpredictably.
What this interaction means in plain words
Posaconazole and Voriconazole 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 belongs to Anti Fungals; Voriconazole belongs to Anti Fungals.
Why it happens
Overlapping CYP3A4 inhibition and additive QT effects; interaction pharmacokinetics are not well characterized.
What to do
Avoid routine combination of azoles. If sequential use is needed, monitor ECG, liver tests and drug levels.
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 Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole Contraindicated
Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Frequently asked questions
Can I take Posaconazole with Voriconazole?
MediHelp rates the interaction as major. Posaconazole and Voriconazole 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. Two azole antifungals given together offer no clear benefit and may increase adverse effects such as QT prolongation, hepatotoxicity and visual disturbances. Both are CYP3A4 inhibitors and voriconazole is also a substrate, so exposure may change unpredictably.
How serious is the interaction between Posaconazole and Voriconazole?
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 routine combination of azoles. If sequential use is needed, monitor ECG, liver tests and drug levels.
What other medicines interact with Voriconazole?
MediHelp also lists interactions of Voriconazole with, for example, Avanafil, Butabarbital, Carbamazepine. The full list is on the Voriconazole page.
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