Goserelin and Relugolix: 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
Goserelin
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 relugolix and goserelin lower testosterone to treat prostate cancer. One known side effect of this kind of hormone therapy is a small change in your heart's electrical timing, called QT prolongation. When two medicines that can do this are used together, the effect may add up, which in rare cases can lead to an irregular heartbeat.
The good news is this is a theoretical concern, not something proven to happen often. Your care team can manage it easily by keeping an eye on your heart rhythm and your blood minerals. Please don't stop either medicine on your own. Just talk with your doctor or pharmacist so they can watch you closely.
Effect: Additive QT interval prolongation. Both agents suppress androgens (GnRH antagonist and agonist, respectively), and androgen deprivation itself can prolong the QT interval, so combined use may be additive.
- Direction: Increased QT prolongation risk (pharmacodynamic, not PK).
- Evidence: Theoretical; severity rated major.
- Onset: Unspecified.
- Higher-risk patients: Congenital long QT, CHF, electrolyte abnormalities.
- Management: Avoid combining when possible. If required, correct and avoid hypokalemia/hypomagnesemia and consider periodic ECG and electrolyte monitoring.
Neither drug requires metabolic activation, so this is purely an additive PD interaction.
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 advantages of androgen deprivation therapy such as relugolix outweigh the possible risks 1. Where feasible, refrain from using relugolix alongside QT prolonging agents. Should coadministration be necessary, steer clear of drugs that produce electrolyte abnormalities (that is, hypokalemia or hypomagnesemia) 2, correct any electrolyte abnormalities, and consider intermittent monitoring of ECGs and electrolytes 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
This interaction is managed by monitoring, not by stopping your treatment. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your care team may weigh the benefits of hormone therapy against your personal heart risk, especially if you have a heart condition or a history of low potassium or magnesium.
- They may check ECGs and blood electrolytes periodically, and correct any low potassium or magnesium.
- Tell your pharmacist or doctor about all your medicines, including any that affect heart rhythm.
Report fainting, dizziness, or palpitations to your care team promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In an analysis of male patients on androgen deprivation therapy (ADT) using individual case safety reports from VigiBase, the international pharmacovigilance database, investigators identified 184 cases of acquired long-QT syndrome (aLQTS) and/or torsades de pointes (TdP; 11% fatal cases), along with 99 cases of sudden death linked to ADT. The majority of aLQTS/TdP cases (62%) and sudden death cases (88%) tied to ADT arose in the absence of other agents recognized to raise TdP risk; nevertheless, exposure to 1 drug and to 2 or more drugs carrying conditional, possible, or known TdP risk was documented in a portion of the aLQTS/TdP events (23% or 43%) and sudden death events (18% and 22%). The agents classified 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 median patient age was approximately 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 taking ADT chiefly for prostate cancer, with some using it for prostatism and androgenic alopecia. The majority of patients were on ADT monotherapy (83%); 17% were receiving ADT combination therapy 3.
Common questions
Can I take Goserelin and Relugolix together?
Using relugolix and goserelin together may add to the risk of QT prolongation, so keep taking both as prescribed while your care team monitors your heart rhythm and blood minerals. Report any fainting or palpitations promptly. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Goserelin and Relugolix 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 Goserelin and Relugolix interaction managed?
This interaction is managed by monitoring, not by stopping your treatment. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your care team may weigh the benefits of hormone therapy against your personal heart risk, especially if you have a heart condition or a history of low potassium or magnesium. They may check ECGs and blood electrolytes periodically,… 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 Goserelin or Relugolix 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 Goserelin
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