Granisetron Transdermal Patch and Metaxalone: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Metaxalone
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
Increased risk of serotonin syndrome
Interaction Deep Dive
Serotonin syndrome has been reported with concomitant use of metaxalone (dosed within the usual therapeutic range) and serotonergic agents. Onset of symptoms such as mental status changes, autonomic instability, neuromuscular aberrations, and gastrointestinal symptoms typically occurs within several hours to a few days, but may occur later. When such concomitant use is required, careful observation is recommended, particularly at initiation of treatment and during dosage adjustment1.
Why it happens (mechanism)
Additive serotonergic effects
Literature reports
1 report — tap to read
a) Serotonin syndrome has been reported with concomitant use of metaxalone (dosed within the usual therapeutic range) and serotonergic agents 1.
Common questions
Can I take Granisetron Transdermal Patch and Metaxalone together?
Increased risk of serotonin syndrome Always confirm with your pharmacist or prescriber before making any change.
How serious is the Granisetron Transdermal Patch and Metaxalone 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Granisetron Transdermal Patch or Metaxalone 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 (1)
- Product Information: SKELAXIN(R) oral tablets, metaxalone oral tablets. King Pharmaceuticals, Inc. (per FDA), Bristol, TN, 2018. DailyMed
Keep reading about Metaxalone
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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