Dacomitinib and Pimozide: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Pimozide
No brand names on recordDacomitinib
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 pimozide exposure
Interaction Deep Dive
Concomitant use of pimozide (CYP2D6 substrate) and strong CYP2D6 inhibitors is contraindicated as it may increase pimozide exposure. In healthy subjects, coadministration of pimozide 2 mg (single dose) and PARoxetine 60 mg resulted in a 151% increase in pimozide AUC and a 62% increase in pimozide Cmax compared to pimozide administered alone. The increase in pimozide AUC and Cmax is related to the CYP2D6 inhibitory properties of PARoxetine2.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated metabolism of pimozide
Literature reports
3 reports — tap to read
a) In healthy subjects, coadministration of pimozide 2 mg (single dose) and PARoxetine 60 mg resulted in a 151% increase in pimozide AUC and a 62% increase in pimozide Cmax compared to pimozide administered alone. The increase in pimozide AUC and Cmax is related to the CYP2D6 inhibitory properties of PARoxetine 2.
b) Coadministration of buPROPion (a CYP2D6 inhibitor) 150 mg twice daily and a single dose of desipramine 50 mg (a CYP2D6 substrate) in healthy volunteers who were extensive CYP2D6 metabolizers (n=15) resulted in a 2-fold, 5-fold, and 2-fold increase in desipramine Cmax, AUC, and t(1/2), respectively. The effect persisted for 7 days following the last dose of buPROPion 3456.
c) Coadministration of a single 45 mg dose of dacomitinib increased dextromethorphan (a CYP2D6 substrate) Cmax by 9.7-fold and AUC by 9.6-fold 1.
Common questions
Can I take Dacomitinib and Pimozide together?
Increased pimozide exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dacomitinib and Pimozide 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Dacomitinib or Pimozide 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 (6)
- Product Information: VIZIMPRO(R) oral tablets, dacomitinib oral tablets. Pfizer Labs (per FDA), New York, NY, 2018. DailyMed
- Product Information: Pimozide oral tablet, pimozide oral tablet. Endo USA, Inc (per DailyMed), Malvern, PA, 2017. DailyMed
- Product Information: WELLBUTRIN XL(R) oral extended-release tablets, bupropion hydrochloride oral extended-release tablets. Bausch Health US, LLC (per FDA), Bridgewater, NJ, 2024. DailyMed
- Product Information: WELLBUTRIN(R) SR oral sustained-release tablets, bupropion hydrochloride oral sustained-release tablets. GlaxoSmithKline (per FDA), Durham, NC, 2024. DailyMed
- Product Information: WELLBUTRIN(R) oral tablets, bupropion hydrochloride oral tablets. GlaxoSmithKline (per FDA), Durham, NC, 2024. DailyMed
- Product Information: FORFIVO XL(R) oral extended-release tablets, bupropion hydrochloride oral extended-release tablets. TWi Pharmaceuticals USA, Inc (per FDA), Paramus, NJ, 2024. DailyMed
Keep reading about Pimozide
Keep reading about Dacomitinib
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