Drug interactions
Fluconazole + Mobocertinib
Severity: Major
Fluconazole and Mobocertinib: 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
Fluconazole increases mobocertinib exposure and both drugs prolong the QT interval, so the risk of serious ventricular arrhythmia is compounded. Mobocertinib carries a boxed warning for QTc prolongation and torsades de pointes.
What this interaction means in plain words
Fluconazole and Mobocertinib 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
CYP3A4 inhibition by fluconazole raises mobocertinib levels, combined with additive QT prolongation.
What to do
Prefer an antifungal that does not inhibit CYP3A4 or prolong QT. If unavoidable, reduce the mobocertinib dose by about half and monitor ECG and electrolytes frequently.
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 Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
Frequently asked questions
Can I take Fluconazole with Mobocertinib?
MediHelp rates the interaction as major. Fluconazole and Mobocertinib 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. Fluconazole increases mobocertinib exposure and both drugs prolong the QT interval, so the risk of serious ventricular arrhythmia is compounded. Mobocertinib carries a boxed warning for QTc prolongation and torsades de pointes.
How serious is the interaction between Fluconazole and Mobocertinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an antifungal that does not inhibit CYP3A4 or prolong QT. If unavoidable, reduce the mobocertinib dose by about half and monitor ECG and electrolytes frequently.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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