Relugolix and Vardenafil: 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
Vardenafil
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 these medicines can affect the timing of your heartbeat in a small way. This is called QT prolongation. Vardenafil (Levitra or Staxyn) is used for erectile function, and relugolix (Orgovyx) lowers testosterone to treat prostate cancer. On their own each has a modest effect on heart rhythm, but taken together the effects can add up and, rarely, could lead to an irregular heartbeat.
Please don't stop either medicine on your own. This is a theoretical concern, meaning it's based on how the drugs work rather than lots of reported cases. Your care team can manage it by checking your heart tracing (ECG) and blood minerals if needed.
Effect: Additive QT interval prolongation with concomitant vardenafil and relugolix. Both agents carry independent QT-prolonging potential; androgen deprivation from relugolix can itself prolong QT.
- Mechanism: Pharmacodynamic (additive), not a metabolic/prodrug interaction.
- Direction: Increased combined torsadogenic risk.
- Evidence: Theoretical; severity rated major.
- Onset: Unspecified.
- Management: Avoid combination when possible. If used together, correct and avoid hypokalemia/hypomagnesemia, and consider periodic ECG and electrolyte monitoring. Extra 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 known 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 agents that prolong the QT interval. 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 monitoring of ECGs and electrolytes 1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
The main goal is to keep your heart rhythm safe while you get the benefit of both medicines.
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may check an ECG (heart tracing) and blood electrolytes from time to time.
- They will want to keep your potassium and magnesium in a normal range, since low levels raise the risk.
- Tell your prescriber if you have a history of long QT syndrome, heart failure, or fainting spells.
- Report symptoms like palpitations, dizziness, or fainting right away.
Your care team can individualize this and may choose an alternative where possible.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A study assessed male patients treated with 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% 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%) related to ADT arose without concurrent exposure to other agents known to raise TdP risk; nevertheless, exposure to 1 drug and to 2 or more drugs carrying conditional, possible, or known TdP risk was noted 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 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 about 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 being 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 Vardenafil together?
Taking vardenafil with relugolix can add up to affect your heart rhythm (QT prolongation), so your care team may monitor your ECG and blood minerals or choose an alternative. Keep taking both as prescribed and report any palpitations, dizziness, or fainting. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Vardenafil 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 Vardenafil interaction managed?
The main goal is to keep your heart rhythm safe while you get the benefit of both medicines. Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may check an ECG (heart tracing) and blood electrolytes from time to time. They will want to keep your potassium and magnesium in a normal range, since low levels raise the risk. Tell your prescriber if you have… 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 Vardenafil 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 Vardenafil
Keep reading about Relugolix
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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