Gemfibrozil and Imatinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Imatinib
Gemfibrozil
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 imatinib trough level or reduced imatinib exposure
Interaction Deep Dive
Repeated coadministration of gemfibrozil, an inhibitor of CYP2C8 with imatinib, a CYP2C8 substrate, may increase imatinib exposure. However in a randomized crossover study in healthy subjects (n=10) who received gemfibrozil 600 mg or placebo twice daily for 6 days, coadministration of a single dose of imatinib 200 mg on day 3 resulted in reduced imatinib exposure in subjects who received gemfibrozil. Impairment in the formation of imatinib's main metabolite, N-desmethylimatinib, was also seen and was reflected in decreased N-desmethylimatinib exposure. However, the CYP2C8-inhibiting action of gemfibrozil may increase imatinib trough levels above the 1000 ng/mL therapeutic threshold with ongoing exposure. Imatinib dose reduction may be necessary with higher or multiple imatinib doses. Caution is warranted if these drugs are concurrently administered1.
Why it happens (mechanism)
Inhibition of CYP2C8-mediated metabolism of imatinib by gemfibrozil; reduced imatinib absorption and impaired CYP2C8-mediated conversion of imatinib to its active metabolite
Literature reports
1 report — tap to read
a) In a randomized crossover study of 10 healthy subjects administered gemfibrozil 600 mg or placebo twice daily for 6 days and imatinib 200 mg on day 3, imatinib peak plasma concentrations (Cmax) and 0-to-12-hour AUC were reduced by 35% and 23%, respectively, compared with placebo (p less than 0.001). Impaired imatinib absorption was seen in all subjects, with the peak plasma concentration/plasma concentration at 24 hours ratio (Cmax/C24h) reduced by 44% (p less than 0.001). Cmax and 0-to-12-hour AUC of imatinib's main metabolite, N-desmethylimatinib, were reduced by 56% and 48%, respectively, compared with placebo (p less than 0.001). Gemfibrozil also reduced the Cmax/C24h ratio of N-desmethylimatinib by 17% (p=0.222). However, imatinib dose reduction may be necessary with higher or multiple imatinib doses, as the CYP2C8-inhibiting action of gemfibrozil may increase imatinib trough levels above the 1000 ng/mL therapeutic threshold with ongoing exposure. Caution is warranted if these drugs are concurrently administered 1.
Common questions
Can I take Gemfibrozil and Imatinib together?
Increased imatinib trough level or reduced imatinib exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Gemfibrozil and Imatinib 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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Gemfibrozil or Imatinib 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)
- Filppula AM, Tornio A, Niemi M, et al: Gemfibrozil impairs imatinib absorption and inhibits the CYP2C8-mediated formation of its main metabolite. Clin Pharmacol Ther 2013; 94(3):383-393. PubMed
Keep reading about Imatinib
Keep reading about Gemfibrozil
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