Relugolix and Pexidartinib: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Pexidartinib
Relugolix
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.
Let's talk about taking pexidartinib (Turalio) and relugolix (Orgovyx) together. Pexidartinib slows down a pump in your body called P-gp that normally helps move relugolix along and out. When that pump is blocked, more relugolix stays in your bloodstream. In fact, a similar blocker raised relugolix levels by about 3 times.
Higher levels can mean more side effects from relugolix, like hot flashes, fatigue, or other reactions. The good news is your care team can manage this by spacing the doses out, watching you more closely, or adjusting your plan. Please don't stop either medicine on your own. Just check with your doctor or pharmacist.
Effect: Increased relugolix exposure. Pexidartinib inhibits P-gp, reducing the efflux transport of relugolix (a P-gp substrate), raising its plasma concentration and adverse-reaction risk. Neither drug requires activation, so the direction is a straightforward increase in relugolix effect.
- Magnitude: A P-gp inhibitor (erythromycin) increased relugolix AUC 3.5-fold and Cmax 2.9-fold.
- Evidence: Probable; severity major.
- Management: Avoid combination if possible. If unavoidable, give relugolix first, separate dosing by at least 6 hours, and monitor for adverse reactions more frequently.
- Relugolix may be interrupted up to 2 weeks for short P-gp inhibitor courses; if interrupted >7 days, restart with 360 mg loading dose, then 120 mg daily.
What happens
Increased relugolix exposure
Interaction Deep Dive
Concurrent administration of relugolix (a P-gp substrate) with P-gp inhibitors should be avoided, since it can raise relugolix exposure and thereby heighten the likelihood of adverse reactions linked to relugolix. When coadministration cannot be avoided, give relugolix or relugolix/estradiol/norethindrone acetate first, allow a gap of at least 6 hours between doses, and increase the frequency of monitoring for adverse reactions12. Relugolix therapy may be paused for as long as 2 weeks to accommodate a brief course of certain P-gp inhibitors, resuming relugolix once the P-gp inhibitor has been stopped. Should relugolix be withheld for more than 7 days, it should be restarted using a loading dose of 360 mg on day one, followed by 120 mg once daily thereafter. In a drug interaction study, giving relugolix (P-gp substrate) together with erythromycin (P-gp inhibitor) raised relugolix AUC and Cmax by 3.5-fold and 2.9-fold, respectively1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix
How to manage this interaction
Your care team will likely try to avoid combining these two when possible. If you do need both, here is what they typically do:
- Take relugolix first, then separate it from pexidartinib by at least 6 hours.
- Monitor you more closely for relugolix side effects.
- Sometimes pause relugolix for a short course of the other drug, then resume it (with a loading dose if the pause is longer than 7 days) as directed by your prescriber.
Keep taking both as prescribed unless your doctor tells you otherwise, and ask your pharmacist how to time your doses.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a study examining drug interactions, giving relugolix (a P-gp substrate) together with erythromycin (a P-gp inhibitor) raised the AUC and Cmax of relugolix by 3.5-fold and 2.9-fold, respectively 1.
Common questions
Can I take Relugolix and Pexidartinib together?
Pexidartinib can raise relugolix levels and side effects by blocking a transport pump; your care team can manage this by avoiding the combo, separating doses by at least 6 hours, or monitoring you more closely. Do not change either medicine on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Pexidartinib 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 is the Relugolix and Pexidartinib interaction managed?
Your care team will likely try to avoid combining these two when possible. If you do need both, here is what they typically do: Take relugolix first, then separate it from pexidartinib by at least 6 hours. Monitor you more closely for relugolix side effects. Sometimes pause relugolix for a short course of the other drug, then resume it (with a loading dose if the pause is longer than 7 days) as di… Management is individual — always follow your own care team's guidance.
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 Relugolix or Pexidartinib 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)
- Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
- Product Information: MYFEMBREE(R) oral tablets, relugolix, estradiol, norethindrone acetate oral tablets. Myovant Sciences Inc (per FDA), Brisbane, CA, 2021. DailyMed
Keep reading about Pexidartinib
Keep reading about Relugolix
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.
Check another combination
Our instant two-drug interaction checker is almost here.
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