Relugolix and Sertindole: 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
Sertindole
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.
Both of these medicines can affect your heart's rhythm. Sertindole (an antipsychotic) and relugolix (used for prostate cancer) can each stretch out a part of your heartbeat called the QT interval. When you take them together, that effect can add up and, in some people, raise the risk of a dangerous irregular heartbeat.
This is based mostly on theory and how these drugs work, not on lots of real-world cases, so try not to worry. Your care team can manage it by keeping your potassium and magnesium in a good range and checking your heart with an ECG when needed. Please talk with your pharmacist or doctor before changing anything.
Mechanism: Additive QT prolongation. Sertindole is a known QT-prolonging antipsychotic; relugolix causes androgen deprivation, which can itself prolong the QT interval. This is a pharmacodynamic (not metabolic) interaction, so neither prodrug status nor enzyme inhibition applies.
- Direction: Additive increase in QT-prolongation risk / torsades de pointes.
- Evidence: Theoretical; severity major; onset unspecified.
- Management: Avoid concomitant use when possible. Weigh benefit vs risk in congenital long QT, CHF, or recurrent electrolyte disturbance. If combined, avoid agents causing hypokalemia/hypomagnesemia, correct electrolytes, and 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 outweigh the possible risks 1. Where feasible, do not use relugolix alongside QT prolonging agents. Should coadministration be necessary, refrain from using drugs that produce electrolyte disturbances (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
Keep taking both medicines as prescribed unless your care team tells you otherwise. Because both can lengthen the QT interval, your team may take steps to keep this safe:
- Deciding whether the benefit of relugolix outweighs the risk, especially if you have congenital long QT, heart failure, or frequent electrolyte problems.
- Keeping potassium and magnesium levels corrected and avoiding drugs that lower them.
- Checking periodic ECGs and electrolytes.
Ask your pharmacist or prescriber whether these two are the best choice for you, and report fainting, dizziness, palpitations, or an irregular heartbeat 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% fatal cases), along with 99 cases of sudden death linked to ADT. The majority of aLQTS/TdP cases (62%) and sudden death cases (88%) related to ADT arose without concurrent use of other agents recognized to raise TdP risk; nonetheless, use of 1 drug and 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 classified as ADTs included abiraterone, gonadotropin-releasing hormone agonists and antagonists, nonsteroidal androgen receptor inhibitors approved for prostate cancer, and 5-alpha-reductase inhibitors approved 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 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 treated for prostatism and androgenic alopecia. Most patients received ADT monotherapy (83%); 17% were on ADT combination therapy 3.
Common questions
Can I take Relugolix and Sertindole together?
Taking sertindole and relugolix together can add up to a higher risk of QT prolongation and irregular heartbeat, so this combo is best avoided; if both are needed, your team should keep your electrolytes in range and monitor your ECG. Talk to your pharmacist or doctor before making any changes. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Sertindole 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 Sertindole interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. Because both can lengthen the QT interval, your team may take steps to keep this safe: Deciding whether the benefit of relugolix outweighs the risk, especially if you have congenital long QT, heart failure, or frequent electrolyte problems. Keeping potassium and magnesium levels corrected and avoiding drugs that lo… 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 Sertindole 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 Sertindole
Keep reading about Relugolix
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