Drug interactions
Fluphenazine + Granisetron
Severity: Moderate
Fluphenazine and Granisetron: 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
Phenothiazine antipsychotics such as fluphenazine can lengthen the QT interval, and granisetron may add to it. This may increase the risk of torsades de pointes in predisposed patients.
What this interaction means in plain words
Fluphenazine and Granisetron 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.
Fluphenazine belongs to Central Nervous System; Granisetron belongs to Gastrointestinal Tract.
Why it happens
Additive QT prolongation through blockade of cardiac potassium channels.
What to do
Monitor the ECG and correct electrolyte abnormalities. Choose an antiemetic with less QT liability if the QTc is already 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 Granisetron
- Apomorphine + Granisetron Contraindicated
- Amiodarone + Granisetron Major
- Amisulpride + Granisetron Major
- Arsenic trioxide + Granisetron Major
- Artemether / lumefantrine + Granisetron Major
- Artemether + Granisetron Major
Other interactions of Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Granisetron?
MediHelp rates the interaction as moderate. Fluphenazine and Granisetron 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. Phenothiazine antipsychotics such as fluphenazine can lengthen the QT interval, and granisetron may add to it. This may increase the risk of torsades de pointes in predisposed patients.
How serious is the interaction between Fluphenazine and Granisetron?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor the ECG and correct electrolyte abnormalities. Choose an antiemetic with less QT liability if the QTc is already prolonged.
What other medicines interact with Granisetron?
MediHelp also lists interactions of Granisetron with, for example, Apomorphine, Amiodarone, Amisulpride. The full list is on the Granisetron page.
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