Dolasetron and Granisetron: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Dolasetron
Granisetron
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of serotonin syndrome and QT-interval prolongation
Interaction Deep Dive
Concomitant use of granisetron with a drug that is a serotonergic and QT-interval prolonging drug may increase the risk of serotonin syndrome2 and the risk of QT-interval prolongation 1. Serotonin syndrome has been reported with the concurrent use of 5-hydroxytryptamine-3 antagonists and serotonergic drugs, primarily in infusion centers or in post-anesthesia care units. If concomitant use is required, monitor for the emergence of serotonin syndrome. Discontinue treatment with granisetron and institute supportive therapy if symptoms of serotonin syndrome occur 2. Additionally, coadministration with other drugs that prolong the QT-interval may result in additive effects on the QT-interval, therefore use with caution 1.
Why it happens (mechanism)
Additive serotonergic effects; additive QT-interval prolongation
Common questions
Can I take Dolasetron and Granisetron together?
Increased risk of serotonin syndrome and QT-interval prolongation Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dolasetron and Granisetron interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Dolasetron or Granisetron need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: KYTRIL(R) IV injection, granisetron HCl IV injection. Genentech USA, Inc, South San Francisco, CA, 2011.
- Product Information: SANCUSO(R) transdermal system, granisetron transdermal system. Kyowa Kirin Inc (per FDA), Bedminster, NJ, 2020. DailyMed
Keep reading about Dolasetron
Keep reading about Granisetron
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