Relugolix and Sevoflurane: 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
Sevoflurane
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.
These two medicines can each affect your heart's rhythm in the same way. Sevoflurane is an anesthesia gas used during surgery, and relugolix (Orgovyx) is a hormone therapy used mainly for prostate cancer. Both can slightly stretch out a part of your heartbeat called the QT interval. When used together, that effect can add up and, in rare cases, lead to an irregular heartbeat.
The good news is that this concern is mostly theoretical, and your care team knows how to handle it. Before surgery they can check your heart tracing and blood minerals, and watch you closely. Just make sure your surgical team and anesthesiologist know you take relugolix.
Effect: Additive QT interval prolongation. Both agents independently prolong the QT interval (sevoflurane via inhalational anesthetic effects on cardiac repolarization; relugolix via androgen-deprivation-related QT effects). Neither is a prodrug; this is a pharmacodynamic, not metabolic, interaction.
- Direction: Additive increase in QT prolongation risk and torsades de pointes potential.
- Onset: Unspecified; relevant acutely during anesthesia.
- Evidence: Theoretical.
- Severity: Major.
- Management: Avoid combination when feasible. If required, correct and avoid hypokalemia/hypomagnesemia, obtain baseline and periodic ECGs, and monitor electrolytes. Exercise particular caution with 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 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 for prolonging the QT interval, weigh whether the advantages of androgen deprivation therapy such as relugolix are greater than the possible risks1. Where feasible, do not combine relugolix with 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 ECG and electrolyte monitoring1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Keep taking your medicines as prescribed, and do not stop anything on your own. Because both drugs can affect heart rhythm, your care team can manage this safely.
- Tell your surgical and anesthesia team that you take relugolix before any procedure.
- Your team may check an ECG (heart tracing) and your electrolytes (like potassium and magnesium) before and during care.
- They will aim to correct any low potassium or magnesium, since these raise the risk.
- Where possible, they may choose an alternative or monitor you more closely.
Raise any history of heart rhythm problems, heart failure, or long QT syndrome 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 examined male patients undergoing androgen deprivation therapy (ADT) using individual case safety reports from VigiBase, the international pharmacovigilance database, and found 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; nevertheless, use of 1 drug and 2 or more drugs carrying conditional, possible, or known TdP risk was documented 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 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 of aLQTS/TdP events was 170 days (range, 7 to 4884 days) while sudden death events occurred at a median of 92 days (range, 0.25 to 4984 days). Patients were primarily receiving ADT for prostate cancer, with some treated for prostatism and androgenic alopecia. The majority of patients were on ADT monotherapy (83%); 17% were receiving ADT combination therapy 3.
Common questions
Can I take Relugolix and Sevoflurane together?
Sevoflurane and relugolix can each prolong the QT interval, so together they may add up and slightly raise the risk of an abnormal heart rhythm; your care team can manage this by checking your ECG and electrolytes and monitoring you closely. Make sure your surgical team knows you take relugolix. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Sevoflurane 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 Sevoflurane interaction managed?
Keep taking your medicines as prescribed, and do not stop anything on your own. Because both drugs can affect heart rhythm, your care team can manage this safely. Tell your surgical and anesthesia team that you take relugolix before any procedure. Your team may check an ECG (heart tracing) and your electrolytes (like potassium and magnesium) before and during care. They will aim to correct any low… 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 Sevoflurane 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 Sevoflurane
Keep reading about Relugolix
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