Drug interactions
Granisetron + Saquinavir
Severity: Major
Granisetron and Saquinavir: 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
Saquinavir boosted with ritonavir prolongs the QT and PR intervals and is contraindicated with other QT-prolonging drugs in some labeling. Granisetron adds to the QT effect, and CYP3A4 inhibition may raise granisetron exposure.
What this interaction means in plain words
Granisetron and Saquinavir 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.
Why it happens
Additive QT prolongation, with CYP3A4 inhibition possibly increasing granisetron levels.
What to do
Avoid if possible and use an antiemetic with less QT liability. If used, obtain a baseline ECG, correct electrolytes and monitor the ECG during treatment.
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
Frequently asked questions
Can I take Granisetron with Saquinavir?
MediHelp rates the interaction as major. Granisetron and Saquinavir 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. Saquinavir boosted with ritonavir prolongs the QT and PR intervals and is contraindicated with other QT-prolonging drugs in some labeling. Granisetron adds to the QT effect, and CYP3A4 inhibition may raise granisetron exposure.
How serious is the interaction between Granisetron and Saquinavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible and use an antiemetic with less QT liability. If used, obtain a baseline ECG, correct electrolytes and monitor the ECG during treatment.
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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