Drug interactions
Ondansetron + Vardenafil
Severity: Moderate
Ondansetron and Vardenafil: 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
Both drugs can lengthen the QT interval, and vardenafil has labeled QT effects at higher doses. Co-use may add to the risk of torsades de pointes, mainly in patients with other risk factors.
What this interaction means in plain words
Ondansetron and Vardenafil 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.
Ondansetron belongs to Gastrointestinal Tract; Vardenafil belongs to Genitourinary.
Why it happens
Additive prolongation of cardiac repolarization.
What to do
Avoid in congenital long QT syndrome and use the lowest effective vardenafil dose. Obtain an ECG and correct electrolytes in patients with heart disease or other QT-prolonging drugs.
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 Vardenafil
- Amyl nitrite + Vardenafil Contraindicated
- Glyceryl trinitrate pr + Vardenafil Contraindicated
- Isosorbide dinitrate + Vardenafil Contraindicated
- Isosorbide mononitrate + Vardenafil Contraindicated
- Nicorandil + Vardenafil Contraindicated
- Nitroglycerin po + Vardenafil Contraindicated
Frequently asked questions
Can I take Ondansetron with Vardenafil?
MediHelp rates the interaction as moderate. Ondansetron and Vardenafil 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. Both drugs can lengthen the QT interval, and vardenafil has labeled QT effects at higher doses. Co-use may add to the risk of torsades de pointes, mainly in patients with other risk factors.
How serious is the interaction between Ondansetron and Vardenafil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid in congenital long QT syndrome and use the lowest effective vardenafil dose. Obtain an ECG and correct electrolytes in patients with heart disease or other QT-prolonging drugs.
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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