Relugolix and Taletrectinib: 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
Taletrectinib
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, relugolix (Orgovyx) and taletrectinib (Ibtrozi), can affect the timing of your heartbeat in a small way. Doctors call this QT prolongation. When two medicines that do this are taken together, the effect can add up, which in rare cases can lead to an irregular heartbeat.
Please don't worry or stop either medicine on your own. This is something your care team knows how to handle. They may check your heart rhythm with an EKG now and then, keep an eye on blood minerals like potassium and magnesium, and make sure everything stays in balance. Bring up any fainting, dizziness, or a fluttering heartbeat right away.
Interaction: Additive QT interval prolongation with coadministration of relugolix (GnRH antagonist) and taletrectinib. Androgen deprivation from GnRH agonists/antagonists can prolong QTc; combining with another QT-prolonging agent increases the risk of torsades de pointes.
- Mechanism: Additive pharmacodynamic effect on cardiac repolarization (not a CYP/transporter PK interaction).
- Direction: Increased QT-prolonging effect; neither drug is a prodrug.
- Evidence: Theoretical; severity rated major.
- Management: Avoid concurrent use where possible. If required, correct and avoid hypokalemia/hypomagnesemia and perform periodic ECG and electrolyte monitoring. Weigh benefit/risk in congenital long QT, CHF, or frequent electrolyte disturbances.
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 those receiving drugs recognized to prolong the QT interval, weigh whether the benefits 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 disturbances (that is, hypokalemia or hypomagnesemia) 2, correct any electrolyte disturbances, and consider periodic monitoring of ECGs and electrolytes 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Because both can add to QT prolongation, your team may take steps to keep you safe:
- Check periodic EKGs to watch your heart rhythm.
- Monitor and correct blood potassium and magnesium, since low levels raise the risk.
- Weigh the benefits of therapy against your personal heart history (for example, long QT syndrome or heart failure).
- Consider an alternative when possible.
Tell your pharmacist or doctor if you feel dizzy, faint, or notice a fluttering or racing heartbeat, and mention any other medicines that affect the heart.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A study examined male patients undergoing androgen deprivation therapy (ADT) using individual case safety reports from VigiBase, the international pharmacovigilance database, and identified 184 cases of acquired long-QT syndrome (aLQTS) and/or torsades de pointes (TdP; 11% of cases 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 concurrent use of other drugs known to raise TdP risk; nevertheless, use of 1 drug and of 2 or more drugs carrying conditional, possible, or known TdP risk was recorded in some 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 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 mainly taking ADT to treat prostate cancer, with some being 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 Taletrectinib together?
Taking relugolix with taletrectinib can add to QT prolongation and, rarely, dangerous heart rhythms. Keep both as prescribed and let your care team monitor your EKG and electrolytes. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Taletrectinib 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 Taletrectinib interaction managed?
Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Because both can add to QT prolongation, your team may take steps to keep you safe: Check periodic EKGs to watch your heart rhythm. Monitor and correct blood potassium and magnesium, since low levels raise the risk. Weigh the benefits of therapy against your personal heart history (for example, long QT synd… 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 Taletrectinib 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 Taletrectinib
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