Drug interactions
Lumacaftor / ivacaftor + Posaconazole
Severity: Major
Lumacaftor / ivacaftor and Posaconazole: major interaction.
Last updated Sources: US FDA label
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
Lumacaftor is a strong CYP3A inducer and may lower posaconazole concentrations. Reduced exposure risks antifungal treatment or prophylaxis failure, which matters in patients with cystic fibrosis. Posaconazole may also raise ivacaftor levels, though induction by lumacaftor typically predominates.
What this interaction means in plain words
Lumacaftor / ivacaftor 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.
Why it happens
Lumacaftor induces CYP3A and other enzymes, which increases posaconazole clearance.
What to do
Avoid if possible or monitor posaconazole trough concentrations and adjust dosing accordingly. Consider an alternative antifungal if levels are inadequate.
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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References
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 Lumacaftor / ivacaftor with Posaconazole?
MediHelp rates the interaction as major. Lumacaftor / ivacaftor 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. Lumacaftor is a strong CYP3A inducer and may lower posaconazole concentrations. Reduced exposure risks antifungal treatment or prophylaxis failure, which matters in patients with cystic fibrosis. Posaconazole may also raise ivacaftor levels, though induction by lumacaftor typically predominates.
How serious is the interaction between Lumacaftor / ivacaftor 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 if possible or monitor posaconazole trough concentrations and adjust dosing accordingly. Consider an alternative antifungal if levels are inadequate.
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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