Relugolix and Ebastine: 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
Relugolix
Ebastine
No brand names on record
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.
Both of your medicines can affect your heart's rhythm in the same way. Relugolix (Orgovyx) lowers testosterone as part of your treatment, and lowering it can gently stretch out a part of your heartbeat called the QT interval. Ebastine, an antihistamine used for allergies, can do the same thing. When two medicines both push in that direction, the effect can add up and, in rare cases, lead to an abnormal heart rhythm.
This is a theoretical concern, meaning it is based on how the drugs work rather than lots of reported cases. Your care team can manage this by checking your heart tracing (ECG) and blood minerals if needed. Please don't stop either drug on your own, just talk with your pharmacist or doctor.
Additive QT prolongation. Relugolix-induced androgen deprivation can prolong the QT interval; ebastine also carries QT-prolonging potential. Combined use may produce additive QTc effects and increase torsades risk.
- Direction: additive pharmacodynamic effect (not a metabolic/prodrug interaction).
- Evidence: theoretical; severity rated major.
- Onset: unspecified.
- Management: avoid concomitant use where possible. Weigh ADT benefit against risk in congenital long QT, CHF, or recurrent electrolyte disturbance. If used together, avoid agents causing hypokalemia/hypomagnesemia, correct electrolytes, and consider periodic ECG and electrolyte monitoring.
What happens
Increased risk of QT interval prolongation
Interaction Deep Dive
When relugolix is given together with medications that prolong the QT interval, the effects on the QT interval are additive. The androgen deprivation produced by GnRH agonists or antagonists can itself lengthen the QT interval. In patients who have congenital long QT syndrome, congestive heart failure, or recurrent electrolyte disturbances, as well as in those receiving drugs recognized to prolong the QT interval, weigh whether the benefits of androgen deprivation therapy such as relugolix outweigh the potential risks 1. Where feasible, do not use relugolix concurrently with QT prolonging agents. Should coadministration be necessary, refrain from using drugs that produce electrolyte disturbances (such as hypokalemia or hypomagnesemia) 2, correct any electrolyte abnormalities, and think about periodically monitoring ECGs and electrolytes 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Both drugs can nudge your heart's QT interval in the same direction, so your care team pays extra attention when they are combined.
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may check an ECG and blood electrolytes (like potassium and magnesium) periodically, and correct any low levels.
- They will consider whether an alternative to one drug is possible, especially if you have a heart condition or a history of electrolyte problems.
- Tell them about any fainting, dizziness, or a fluttering or pounding heartbeat right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A study assessed male patients undergoing androgen deprivation therapy (ADT) using individual case safety reports from VigiBase, the international pharmacovigilance database. It identified 184 cases of acquired long-QT syndrome (aLQTS) and/or torsades de pointes (TdP; 11% of which were fatal), along with 99 cases of sudden death linked to ADT. The majority of aLQTS/TdP cases (62%) and sudden death cases (88%) associated with ADT arose without exposure to other agents recognized as increasing TdP risk; nevertheless, exposure to 1 drug and to 2 or more drugs carrying conditional, possible, or known TdP risk was documented in some aLQTS/TdP (23% or 43%) and sudden death (18% and 22%) events. The agents regarded as ADTs included abiraterone, gonadotropin-releasing hormone agonists and antagonists, nonsteroidal androgen receptor inhibitors indicated for prostate cancer, and 5-alpha-reductase inhibitors indicated for androgenic alopecia and prostatism. Among the 10 ADTs assessed, 7 showed a disproportional association (reporting odds ratio, 1.4 to 4.7) with aLQTS, TdP, or sudden death, namely leuprorelin, goserelin, triptorelin, degarelix, bicalutamide, finasteride, and dutasteride. The patients had a median age of roughly 76 years, and the median time to onset was 170 days (range, 7 to 4884 days) for aLQTS/TdP events and 92 days (range, 0.25 to 4984 days) for sudden death events. Patients were mainly receiving ADT for prostate cancer, with some treated for prostatism and androgenic alopecia. Most patients received ADT as monotherapy (83%); 17% were on ADT combination therapy 3.
Common questions
Can I take Relugolix and Ebastine together?
Relugolix and ebastine can each prolong the QT interval, and using them together may add up. Keep taking both as prescribed and ask your doctor or pharmacist whether ECG and electrolyte checks are needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Ebastine 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 Ebastine interaction managed?
Both drugs can nudge your heart's QT interval in the same direction, so your care team pays extra attention when they are combined. Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may check an ECG and blood electrolytes (like potassium and magnesium) periodically, and correct any low levels. They will consider whether an alternative to one drug is pos… Management is individual — always follow your own care team's guidance.
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 Relugolix or Ebastine 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 (3)
- Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
- Lyon AR, Lopez-Fernandez T, Couch LS, et al: 2022 ESC guidelines on cardio-oncology developed in collaboration with the European Hematology Association (EHA), the European Society for Therapeutic Radiology and Oncology (ESTRO) and the International Cardio-Oncology Society (IC-OS). Eur Heart J 2022; 43(41):4229-4361.
- Salem JE, Yang T, Moslehi JJ, et al: Androgenic effects on ventricular repolarization: a translational study from the international pharmacovigilance database to iPSC-cardiomyocytes. Circulation 2019; 140(13):1070-1080. PubMed
Keep reading about Relugolix
Keep reading about Ebastine
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