Drug interactions
ondansetron + voriconazole
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.
Overview
Additive QTc prolongation with potential torsades de pointes; voriconazole (strong CYP3A4 inhibitor) may increase ondansetron exposure, further elevating arrhythmia risk.
Mechanism of action
Pharmacodynamic additive QT prolongation; pharmacokinetic increase in ondansetron via CYP3A4 inhibition by voriconazole.
Clinical management
Avoid combination if possible. If necessary, use lowest effective ondansetron dose, correct K/Mg, obtain baseline and follow-up ECGs, monitor QTc and for palpitations/syncope; consider alternative antiemetic with lower QT risk.
Drug reference
References
Frequently asked questions
Can I take ondansetron with voriconazole?
The interaction is rated: Major. Additive QTc prolongation with potential torsades de pointes; voriconazole (strong CYP3A4 inhibitor) may increase ondansetron exposure, further elevating arrhythmia risk.
How serious is the interaction between ondansetron and voriconazole?
The interaction is rated: Major. Evidence level: High.
How is the interaction between ondansetron and voriconazole managed?
Avoid combination if possible. If necessary, use lowest effective ondansetron dose, correct K/Mg, obtain baseline and follow-up ECGs, monitor QTc and for palpitations/syncope; consider alternative antiemetic with lower QT risk.
Why do ondansetron and voriconazole interact?
Pharmacodynamic additive QT prolongation; pharmacokinetic increase in ondansetron via CYP3A4 inhibition by voriconazole.
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