Relugolix and Olanzapine: 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
Olanzapine
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.
Taking olanzapine (a medicine for mood and mental health) together with relugolix (Orgovyx, used in prostate cancer) can add up in one specific way. Both can affect the heart's electrical timing, something called the QT interval. When that timing is stretched too far, it can raise the risk of an unusual heartbeat.
Right now this is a theoretical concern based on how each drug works, not on lots of real cases with these two together. Please don't stop either medicine on your own. Your care team can manage this well by checking your heart tracing (ECG) and blood levels of things like potassium and magnesium when needed. Talk with your pharmacist or doctor if you have questions.
Effect: Additive QT-interval prolongation. Both agents independently prolong QT (olanzapine as a QT-prolonging antipsychotic; relugolix via androgen deprivation), so combined use raises torsadogenic risk. Neither is a prodrug; this is a pharmacodynamic, not pharmacokinetic, interaction.
- Severity: Major; evidence: theoretical; onset: unspecified.
- Higher-risk patients: congenital long QT, CHF, recurrent electrolyte abnormalities.
- Management: Avoid combination where possible. If required, correct and maintain normal K+/Mg2+, avoid additional QT-prolonging or electrolyte-depleting drugs, and perform periodic ECG and electrolyte monitoring. Weigh benefit of ADT against risk.
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 abnormalities, as well as in those receiving drugs recognized to prolong the QT interval, weigh whether the benefits 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 such coadministration cannot be avoided, refrain from using drugs that produce electrolyte abnormalities (namely hypokalemia or hypomagnesemia) 2, correct any electrolyte abnormalities, and consider periodic ECG and electrolyte monitoring 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Both medicines can affect your heart's rhythm, so your care team pays extra attention when they are used together.
- Keep taking both exactly as prescribed unless your doctor tells you otherwise.
- Your team may order periodic ECGs (heart tracings) and blood tests for potassium and magnesium.
- They will correct any low potassium or magnesium and try to avoid other drugs that lower these.
- They will weigh whether the benefits of relugolix outweigh the risks, especially if you have long QT syndrome, heart failure, or frequent electrolyte problems.
Tell your pharmacist or doctor about fainting, palpitations, dizziness, or all other medicines you take.
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, and 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 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 aLQTS/TdP events (23% or 43%) and sudden death events (18% and 22%). 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. 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 principally receiving ADT to treat prostate cancer, with some receiving it for prostatism and androgenic alopecia. Most patients were on ADT monotherapy (83%); 17% were receiving ADT combination therapy 3.
Common questions
Can I take Relugolix and Olanzapine together?
Olanzapine and relugolix can both stretch the heart's QT interval, so together they may raise the risk of an abnormal heartbeat. Keep taking both as prescribed and let your care team monitor your ECG and electrolytes. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Olanzapine 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 Olanzapine interaction managed?
Both medicines can affect your heart's rhythm, so your care team pays extra attention when they are used together. Keep taking both exactly as prescribed unless your doctor tells you otherwise. Your team may order periodic ECGs (heart tracings) and blood tests for potassium and magnesium. They will correct any low potassium or magnesium and try to avoid other drugs that lower these. They will weig… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Relugolix or Olanzapine 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 Olanzapine
Keep reading about Relugolix
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