Drug interactions
Granisetron + Paroxetine
Severity: Moderate
Granisetron and Paroxetine: 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 raise serotonergic activity, and rare cases of serotonin syndrome have been reported when 5-HT3 antagonists are given with SSRIs. Paroxetine and granisetron may also each have a small effect on QT interval. The overall risk is low in most patients but the consequences can be serious.
What this interaction means in plain words
Granisetron and Paroxetine 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.
Granisetron belongs to Gastrointestinal Tract; Paroxetine belongs to Central Nervous System.
Why it happens
Additive pharmacodynamic serotonergic effects, with a possible minor additive effect on cardiac repolarisation.
What to do
Co-administration is acceptable when clinically needed; watch for agitation, tremor, hyperreflexia, diarrhoea and fever after starting or increasing doses. Consider an ECG if other QT-prolonging risks or electrolyte disturbances are present.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Granisetron with Paroxetine?
MediHelp rates the interaction as moderate. Granisetron and Paroxetine 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 raise serotonergic activity, and rare cases of serotonin syndrome have been reported when 5-HT3 antagonists are given with SSRIs. Paroxetine and granisetron may also each have a small effect on QT interval. The overall risk is low in most patients but the consequences can be serious.
How serious is the interaction between Granisetron and Paroxetine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Co-administration is acceptable when clinically needed; watch for agitation, tremor, hyperreflexia, diarrhoea and fever after starting or increasing doses. Consider an ECG if other QT-prolonging risks or electrolyte disturbances are present.
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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