Relugolix and Givinostat: 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
Givinostat
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.
These two medicines can each affect your heart's rhythm. Relugolix (Orgovyx) lowers testosterone, and that hormone change can slightly stretch out part of the heart's electrical cycle, called the QT interval. Givinostat (Duvyzat) can do the same thing. Taken together, those effects can add up, which in rare cases could lead to an irregular heartbeat.
The good news is this is a possible, theoretical concern, not something guaranteed to happen. Your care team can watch for it. Please don't stop either medicine on your own. Just talk with your pharmacist or doctor so they can decide the safest plan for you.
Additive QT prolongation. Relugolix-induced androgen deprivation can prolong the QT interval, and givinostat carries its own QT liability. Concurrent use may produce additive PD effects on cardiac repolarization, increasing torsades risk.
- Direction: additive, not metabolic; neither drug is a prodrug.
- Evidence: theoretical; severity: major; onset: unspecified.
- Management: avoid combination when possible. Weigh benefit vs risk in congenital long QT, CHF, or electrolyte instability. If used together, correct and maintain K+ and Mg2+, avoid additional QT-prolonging or electrolyte-depleting agents, and obtain 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. 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
This can usually be managed with monitoring. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your team may check ECGs and electrolytes (potassium and magnesium) from time to time, and correct any low levels.
- They will try to avoid other medicines that stretch the QT interval or lower electrolytes.
- Tell your care team if you have a history of long QT syndrome, heart failure, or frequent electrolyte problems.
- Report fainting, palpitations, or a racing/irregular heartbeat right away.
Ask your pharmacist before adding any new prescription, over-the-counter, or supplement product.
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 undergoing 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% 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%) tied to ADT arose without concurrent use of other agents recognized to raise TdP risk; nevertheless, use of 1 drug and of 2 or more drugs carrying conditional, possible, or known TdP risk was reported 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 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 primarily on ADT for prostate cancer, with some treated for prostatism and androgenic alopecia. Most patients received ADT as monotherapy (83%), while 17% were on ADT combination therapy 3.
Common questions
Can I take Relugolix and Givinostat together?
Relugolix and givinostat can each prolong the QT interval, so combining them may add up and slightly raise the risk of a dangerous heart rhythm; your care team can manage this with ECG and electrolyte monitoring, so don't stop either drug on your own, just check with them. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Givinostat 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 Givinostat interaction managed?
This can usually be managed with monitoring. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your team may check ECGs and electrolytes (potassium and magnesium) from time to time, and correct any low levels. They will try to avoid other medicines that stretch the QT interval or lower electrolytes. Tell your care team if you have a history of long QT syn… 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 Givinostat 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 Givinostat
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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