Relugolix and Desflurane: 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
Desflurane
Relugolix
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 given two medicines that can each affect your heart's electrical rhythm. Desflurane is an anesthesia gas used during surgery, and relugolix (Orgovyx) lowers testosterone to treat prostate cancer. Both can stretch out a part of the heartbeat called the QT interval. When used together, that effect can add up, which in rare cases can lead to an irregular heartbeat.
The good news is this is a theoretical concern, and your surgical and cancer teams know how to watch for it. They can check your heart rhythm and blood minerals (like potassium and magnesium) and keep them balanced. Keep taking your medicines as prescribed and let your doctors know you take both.
Effect: Additive QT interval prolongation. Both agents independently prolong the QT interval (desflurane is a known QT-prolonging volatile anesthetic; relugolix, a GnRH antagonist, prolongs QT via androgen deprivation). Combined use is additive (pharmacodynamic, not metabolic; neither is a prodrug here).
- Severity: Major; evidence: theoretical; onset: unspecified.
- Higher risk: congenital long QT, CHF, electrolyte abnormalities, other QT-prolonging drugs.
- Management: Avoid concomitant use where possible. If required, correct and avoid causes of hypokalemia/hypomagnesemia, and consider periodic ECG and electrolyte monitoring. Weigh benefits of ADT against risk.
What happens
Increased risk of QT interval prolongation
Interaction Deep Dive
When relugolix is given together with agents 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 benefits of androgen deprivation therapy such as relugolix are greater than the possible risks 1. Where feasible, do not use relugolix at the same time as QT prolonging agents. Should coadministration be necessary, refrain from using drugs that produce electrolyte abnormalities (that is, 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
This is a manageable, mostly precautionary concern. Your care team can tailor how they handle it:
- Keep taking both as prescribed unless your team tells you otherwise, and make sure your surgical and oncology teams know you take relugolix.
- Your team may check an ECG (heart tracing) and blood electrolytes (potassium, magnesium) periodically and correct any imbalances.
- Where possible, they may avoid combining QT-prolonging drugs, especially if you have a heart rhythm condition or heart failure.
Raise any history of fainting, palpitations, or irregular heartbeat with your pharmacist or doctor.
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 in 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 agents recognized to elevate TdP risk; nonetheless, use of 1 drug and 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 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. The 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 mainly receiving ADT for prostate cancer, with some treated for prostatism and androgenic alopecia. Most patients were on ADT monotherapy (83%), whereas 17% were receiving ADT combination therapy 3.
Common questions
Can I take Relugolix and Desflurane together?
Desflurane and relugolix can each prolong the QT interval, so together the effect may add up. Keep taking both as prescribed and let your care team monitor your heart rhythm and electrolytes. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Desflurane 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 Desflurane interaction managed?
This is a manageable, mostly precautionary concern. Your care team can tailor how they handle it: Keep taking both as prescribed unless your team tells you otherwise, and make sure your surgical and oncology teams know you take relugolix. Your team may check an ECG (heart tracing) and blood electrolytes (potassium, magnesium) periodically and correct any imbalances. Where possible, they may avoid… 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 Desflurane 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 Desflurane
Keep reading about Relugolix
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