Drug interactions
Ciprofloxacin + Ondansetron
Severity: Moderate
Ciprofloxacin 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
Both can prolong the QT interval, so together they may increase the likelihood of torsades de pointes. Patients with electrolyte abnormalities, heart disease or other QT-prolonging therapy are at greatest risk.
What this interaction means in plain words
Ciprofloxacin 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.
Ciprofloxacin belongs to Anti Bacterial; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Additive QT prolongation via cardiac potassium channel blockade; ciprofloxacin has a relatively modest QT effect.
What to do
Correct hypokalemia and hypomagnesemia and obtain an ECG in at-risk patients. Avoid in congenital long QT syndrome or choose another antibiotic or antiemetic.
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 Ciprofloxacin
- Agomelatine + Ciprofloxacin Contraindicated
- Ciprofloxacin + Fezolinetant Contraindicated
- Ciprofloxacin + Thioridazine Contraindicated
- Ciprofloxacin + Tizanidine Contraindicated
- Ciprofloxacin + Vandetanib Contraindicated
- Alosetron + Ciprofloxacin Major
Frequently asked questions
Can I take Ciprofloxacin with Ondansetron?
MediHelp rates the interaction as moderate. Ciprofloxacin 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. Both can prolong the QT interval, so together they may increase the likelihood of torsades de pointes. Patients with electrolyte abnormalities, heart disease or other QT-prolonging therapy are at greatest risk.
How serious is the interaction between Ciprofloxacin 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: Correct hypokalemia and hypomagnesemia and obtain an ECG in at-risk patients. Avoid in congenital long QT syndrome or choose another antibiotic or antiemetic.
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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