Vinflunine 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
Vinflunine
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.
You've been prescribed two medicines, relugolix (Orgovyx) and vinflunine. Each one can affect the timing of your heartbeat, causing something called QT prolongation. When two medicines that both do this are taken together, the effect can add up and, in rare cases, lead to a dangerous irregular heartbeat.
Right now this concern is based on how these drugs work rather than lots of real-world reports, so please don't worry. Your care team knows how to handle this. They may check your heart rhythm with an ECG, keep an eye on blood minerals like potassium and magnesium, and decide the safest plan for you. Keep taking both as prescribed and talk with your doctor or pharmacist with any questions.
Effect: Additive QT interval prolongation with combined relugolix and vinflunine.
Mechanism: Both agents independently prolong the QT interval (relugolix via androgen-deprivation-related effects; vinflunine has documented QT liability). The effect is pharmacodynamic and additive, not a metabolic/prodrug issue.
- Direction: Increased QT prolongation / torsades risk.
- Evidence: Theoretical; onset unspecified.
- Management: Avoid concomitant use when possible. If required, weigh benefit vs risk (especially in congenital long QT, CHF, electrolyte disturbances). Correct and avoid hypokalemia/hypomagnesemia; perform 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 and 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 are greater than the possible risks 1. Where feasible, do not use relugolix alongside QT prolonging agents. When coadministration cannot be avoided, refrain from using drugs that produce electrolyte abnormalities (that is, hypokalemia or hypomagnesemia) 2, correct any electrolyte abnormalities, and consider periodic monitoring of ECGs and electrolytes 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
The main concern is that both drugs can lengthen the QT interval, so your care team's goal is to keep your heart rhythm safe.
- Keep taking both medicines as prescribed unless your doctor tells you otherwise.
- Your team may check ECGs and blood minerals (potassium and magnesium) from time to time, and correct any low levels.
- They will weigh the benefits against the risks, especially if you have a heart rhythm condition, heart failure, or frequent electrolyte problems. In some cases they may choose an alternative.
- Tell your prescriber or pharmacist about all your medicines, and report fainting, palpitations, or dizziness right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In an investigation of male patients undergoing androgen deprivation therapy (ADT) using individual case safety reports from VigiBase, the international pharmacovigilance database, researchers 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 (62%) and sudden death (88%) cases connected to ADT arose without concurrent use of other agents recognized to elevate TdP risk; nevertheless, use of 1 drug and use of 2 or more drugs carrying conditional, possible, or known TdP risk was noted in a portion of aLQTS/TdP (23% or 43%) and sudden death (18% and 22%) events. The agents classified as ADTs included abiraterone, gonadotropin-releasing hormone agonists and antagonists, nonsteroidal androgen receptor inhibitors used for prostate cancer, and 5-alpha-reductase inhibitors used for androgenic alopecia and prostatism. Among the 10 ADTs assessed, 7 demonstrated 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 of aLQTS/TdP events was 170 days (range, 7 to 4884 days), while for sudden death events it was 92 days (range, 0.25 to 4984 days). Patients were taking ADT chiefly to manage prostate cancer, with some receiving it for prostatism and androgenic alopecia. The bulk of patients were on ADT monotherapy (83%); 17% were on ADT combination therapy 3.
Common questions
Can I take Vinflunine and Relugolix together?
Relugolix and vinflunine can each stretch the QT interval, so together the risk of an irregular heartbeat adds up; your care team can manage this with ECG and electrolyte monitoring, and by avoiding the combination when possible. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Vinflunine 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 Vinflunine and Relugolix interaction managed?
The main concern is that both drugs can lengthen the QT interval, so your care team's goal is to keep your heart rhythm safe. Keep taking both medicines as prescribed unless your doctor tells you otherwise. Your team may check ECGs and blood minerals (potassium and magnesium) from time to time, and correct any low levels. They will weigh the benefits against the risks, especially if you have a hea… 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 Vinflunine 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 Vinflunine
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