Drug interactions
Itraconazole + Ondansetron
Severity: Moderate
Itraconazole and Ondansetron: moderate 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
Itraconazole can prolong the QT interval and inhibits CYP3A4, which contributes to ondansetron metabolism. The combination may increase ondansetron exposure and QT-related arrhythmic risk.
What this interaction means in plain words
Itraconazole and Ondansetron can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Itraconazole belongs to Anti Fungals; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Additive QT prolongation with CYP3A4 inhibition by itraconazole modestly raising ondansetron levels.
What to do
Check ECG and electrolytes at baseline when other risk factors exist, and use the lowest effective ondansetron dose. Consider an alternative antiemetic if QTc is prolonged.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
Other interactions of Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Frequently asked questions
Can I take Itraconazole with Ondansetron?
MediHelp rates the interaction as moderate. Itraconazole and Ondansetron can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Itraconazole can prolong the QT interval and inhibits CYP3A4, which contributes to ondansetron metabolism. The combination may increase ondansetron exposure and QT-related arrhythmic risk.
How serious is the interaction between Itraconazole and Ondansetron?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check ECG and electrolytes at baseline when other risk factors exist, and use the lowest effective ondansetron dose. Consider an alternative antiemetic if QTc is prolonged.
What other medicines interact with Ondansetron?
MediHelp also lists interactions of Ondansetron with, for example, Apomorphine, Thioridazine, Vandetanib. The full list is on the Ondansetron page.
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