Relugolix and Solifenacin: 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
Solifenacin
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.
Both of your medicines can affect your heart's electrical rhythm in a small way. Solifenacin (for an overactive bladder) and relugolix (Orgovyx, used to lower testosterone) can each slightly lengthen a part of the heartbeat called the QT interval. When taken together, those effects can add up, which in rare cases could lead to an abnormal heart rhythm.
The good news is this is mostly a theoretical concern, and your care team can manage it easily. They may check an ECG or your blood minerals (like potassium and magnesium) from time to time. Keep taking both as prescribed, and let your doctor or pharmacist know if you feel faint, dizzy, or notice a fluttering heartbeat.
Effect: Additive QT interval prolongation with combined solifenacin and relugolix.
Mechanism: Pharmacodynamic (additive). Solifenacin carries a QT-prolonging signal; androgen deprivation from relugolix (a GnRH antagonist) may also prolong QT. Neither is a prodrug; effect is additive, not metabolic.
- Evidence: Theoretical; onset unspecified.
- Risk factors: Congenital long QT, CHF, hypokalemia/hypomagnesemia, other QT-prolonging agents.
- Management: Avoid combination when feasible. If required, correct and maintain electrolytes, avoid agents causing hypokalemia/hypomagnesemia, and consider 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 or 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 outweigh the possible risks 1. Where feasible, do not use relugolix concurrently with QT prolonging agents. When coadministration cannot be avoided, refrain from using drugs that produce electrolyte abnormalities (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
This combination is generally best avoided when there is a good alternative, but if your care team decides you need both, they can manage it safely.
- Keep taking both exactly as prescribed unless your doctor tells you otherwise.
- Your team may check ECGs and blood minerals (potassium and magnesium) from time to time and correct any low levels.
- Tell your prescriber if you have a history of heart rhythm problems, heart failure, or long QT syndrome.
- Report symptoms like fainting, dizziness, palpitations, or a racing heart right away.
Ask your pharmacist before adding any new medicine, since some others also affect QT.
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% 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 elevate TdP risk; nonetheless, use of 1 drug and of 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. 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 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 receiving ADT chiefly for prostate cancer, with some treated 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 Solifenacin together?
Taking solifenacin and relugolix together can add up to a slightly higher risk of QT prolongation, so keep both as prescribed and let your care team monitor your ECG and electrolytes and watch for fainting or palpitations. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Solifenacin 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 Solifenacin interaction managed?
This combination is generally best avoided when there is a good alternative, but if your care team decides you need both, they can manage it safely. Keep taking both exactly as prescribed unless your doctor tells you otherwise. Your team may check ECGs and blood minerals (potassium and magnesium) from time to time and correct any low levels. Tell your prescriber if you have a history of heart rhyt… 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 Solifenacin 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 Solifenacin
Keep reading about Relugolix
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