Drug Interaction Report

Apomorphine and Granisetron Transdermal Patch: Interaction Details

A pharmacist-reviewed analysis of the Apomorphine and Granisetron Transdermal Patch interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Granisetron Transdermal Patch

Sancuso Sancuso®
+

Apomorphine

Apokyn Kynmobi Onapgo
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Contraindicated
These should generally not be used together.
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.

Of 73 documented Apomorphine interactions, 5 are rated contraindicated — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Contraindicated

What happens

Increased risk of profound hypotension and altered consciousness and an increased risk of QT interval prolongation, associated with torsade's de pointes and sudden death

Interaction Deep Dive

Coadministration of apomorphine with granisetron is contraindicated, as it may cause profound hypotension and loss of consciousness. Concomitant use may also increase QT interval prolongation12.

Why it happens (mechanism)

Additive hypotensive effects; additive QT interval prolongation

Literature reports

1 report — tap to read

a) Based on reports, profound hypotension and loss of consciousness has been observed in patients when apomorphine was coadministered with ondansetron (serotonin antagonist). Although torsades de pointes has not been observed in association with the use of apomorphine at recommended doses in clinical studies, experience is too limited to rule out an increased risk 12.

Common questions

Can I take Apomorphine and Granisetron Transdermal Patch together?

Increased risk of profound hypotension and altered consciousness and an increased risk of QT interval prolongation, associated with torsade's de pointes and sudden death Always confirm with your pharmacist or prescriber before making any change.

How serious is the Apomorphine and Granisetron Transdermal Patch 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 Apomorphine or Granisetron Transdermal Patch 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)

  1. Product Information: ONAPGO subcutaneous injection, apomorphine HCl subcutaneous injection. MDD US Operations LLC (per FDA), Rockville, MD, 2025. DailyMed
  2. Product Information: APOKYN(R) subcutaneous injection, apomorphine HCl subcutaneous injection. MDD US Operations LLC (per FDA), Rockville, MD, 2025. DailyMed
Was this write-up helpful?
Granisetron Transdermal Patch

Keep reading about Granisetron Transdermal Patch

All Granisetron Transdermal Patch interactions (281) Granisetron Transdermal Patch drug information
Also serious with: Phenelzine Pimozide Piperaquine Saquinavir
Apomorphine

Keep reading about Apomorphine

All Apomorphine interactions (73)
Also serious with: Dolasetron Dolasetron Injection Granisetron Injection Palonosetron Injection
Beyond drug–drug

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:

Apomorphine + Activated Charcoal St. John's Wort Ayahuasca Bitter Melon Black Horehound Black Pepper Breadfruit Brussels Sprout + 59 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.