Relugolix and Fluvoxamine: 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
Fluvoxamine
No brand names on recordRelugolix
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.
You've been prescribed relugolix (Orgovyx) along with fluvoxamine. Here's what matters: fluvoxamine can block a 'pump' in your gut (called P-gp) that normally limits how much relugolix gets absorbed. When that pump is blocked, more relugolix ends up in your body, which can raise your chance of side effects.
The good news is that this is very manageable. Your care team may space the two medicines apart, watch you more closely, or adjust your plan. Please don't stop or change either drug on your own. Just check in with your pharmacist or doctor so they can set up the safest schedule for you.
Effect: Increased relugolix exposure. Fluvoxamine is a P-gp inhibitor; relugolix is a P-gp substrate, so inhibition of intestinal P-gp-mediated efflux raises relugolix AUC and Cmax and increases adverse-reaction risk.
- Magnitude (reference): erythromycin (P-gp inhibitor) raised relugolix AUC ~3.5-fold and Cmax ~2.9-fold.
- Evidence: probable; onset unspecified.
- Management: Avoid coadministration if possible. If unavoidable, give relugolix first, separate by at least 6 hours, and monitor 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 relugolix-related adverse reactions. When the combination 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 when a brief course of certain P-gp inhibitors is needed, with relugolix resumed once the P-gp inhibitor has been stopped. Should relugolix be interrupted for more than 7 days, restart it 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 the AUC and Cmax of relugolix 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
This interaction is manageable with the right plan from your care team. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your team may avoid using them together, or if both are needed, have you take relugolix first and separate the doses by at least 6 hours.
- They may monitor you more closely for relugolix side effects.
- In some cases relugolix can be paused for a short course of the other drug and restarted afterward (sometimes with a loading dose your team decides).
Ask your pharmacist or prescriber to confirm your dosing schedule and what side effects to watch for.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) During a drug interaction study, giving relugolix (a P-gp substrate) together with erythromycin (a P-gp inhibitor) raised relugolix AUC by 3.5-fold and Cmax by 2.9-fold, respectively 1.
Common questions
Can I take Relugolix and Fluvoxamine together?
Fluvoxamine can raise relugolix levels and side-effect risk by blocking its P-gp transporter; keep taking both as prescribed and ask your pharmacist or doctor to set up safe timing and monitoring. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Fluvoxamine 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 Fluvoxamine interaction managed?
This interaction is manageable with the right plan from your care team. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your team may avoid using them together, or if both are needed, have you take relugolix first and separate the doses by at least 6 hours. They may monitor you more closely for relugolix side effects. In some cases relugolix can be paus… 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 Fluvoxamine 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 Fluvoxamine
Keep reading about Relugolix
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