Drug interactions
Granisetron + Posaconazole
Severity: Major
Granisetron and Posaconazole: major interaction.
Last updated Sources: US FDA label
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
Posaconazole can prolong the QT interval and strongly inhibits CYP3A4, which participates in granisetron metabolism. Together they may produce additive QT effects and higher granisetron exposure.
What this interaction means in plain words
Granisetron and Posaconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Granisetron belongs to Gastrointestinal Tract; Posaconazole belongs to Anti Fungals.
Why it happens
Additive QT prolongation plus CYP3A4 inhibition that may raise granisetron concentrations.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during combined use. Consider an alternative antiemetic if the QTc lengthens.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
Frequently asked questions
Can I take Granisetron with Posaconazole?
MediHelp rates the interaction as major. Granisetron and Posaconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Posaconazole can prolong the QT interval and strongly inhibits CYP3A4, which participates in granisetron metabolism. Together they may produce additive QT effects and higher granisetron exposure.
How serious is the interaction between Granisetron and Posaconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during combined use. Consider an alternative antiemetic if the QTc lengthens.
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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