Granisetron Transdermal Patch and Tranylcypromine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tranylcypromine
Granisetron Transdermal Patch
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
An increased risk of serotonin syndrome
Interaction Deep Dive
Concurrent use of tranylcypromine and granisetron is contraindicated, as it may lead to severe or life-threatening reactions including hypertensive crisis or serotonin syndrome. Discontinue granisetron and wait at least 1 week or 4 to 5 half-lives (whichever is longer) of granisetron before initiating tranylcypromine. The potential for interactions persists after discontinuation of tranylcypromine tablets until MAO activity has sufficiently recovered. Inhibition of MAO may persist up to 10 days following discontinuation2. If coadministration is required, monitor for the emergence of serotonin syndrome. Discontinue treatment with granisetron and institute supportive therapy if symptoms of serotonin syndrome occur 1.
Why it happens (mechanism)
Additive serotonergic effects
Common questions
Can I take Granisetron Transdermal Patch and Tranylcypromine together?
An increased risk of serotonin syndrome Always confirm with your pharmacist or prescriber before making any change.
How serious is the Granisetron Transdermal Patch and Tranylcypromine interaction?
It is rated contraindicated. These should generally not be used together.
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 Granisetron Transdermal Patch or Tranylcypromine 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)
Keep reading about Tranylcypromine
Keep reading about Granisetron Transdermal Patch
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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