Telavancin and Relugolix: 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
Telavancin
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 your heart's rhythm. Relugolix (Orgovyx) is used for prostate cancer, and telavancin (Vibativ) is an antibiotic. Each one can slightly stretch out the electrical timing of your heartbeat, something doctors call the QT interval. When you take them together, that effect can add up and, in rare cases, lead to an irregular heartbeat.
Please don't worry or stop either medicine on your own. This is a possible risk, not something that happens to everyone. Your care team can manage it easily, often by checking your heart rhythm with an EKG and keeping your minerals like potassium and magnesium in a healthy range. Just make sure your pharmacist and doctor know you take both.
Interaction: Additive QT interval prolongation when relugolix is combined with telavancin.
- Mechanism: Both agents independently prolong the QT interval (relugolix via androgen deprivation; telavancin has documented QTc effects). Effect is pharmacodynamic and additive. Neither is a prodrug relevant here.
- Direction: Increased risk of QTc prolongation and torsades de pointes.
- Evidence: Theoretical; severity rated major. Onset unspecified.
- Management: Avoid concurrent use when possible. If required, correct and avoid hypokalemia/hypomagnesemia, and perform periodic ECG and electrolyte monitoring. Weigh benefit/risk in patients 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 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 abnormalities, as well as 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 hazards1. Where feasible, do not use relugolix alongside QT prolonging agents. Should combined use be necessary, refrain from drugs that produce electrolyte abnormalities (that is, hypokalemia or hypomagnesemia)2, correct any electrolyte abnormalities, and think about periodic monitoring of ECGs and electrolytes1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
Keep taking both medicines as prescribed unless your doctor or pharmacist tells you otherwise. Here is how a care team usually handles this:
- They may decide whether an alternative antibiotic is a better fit, or whether the benefit of relugolix outweighs the risk in your case.
- If both are needed, they will often check an EKG and your electrolytes (potassium and magnesium) and correct any low levels.
- Let them know if you have a history of heart rhythm problems, heart failure, or long QT syndrome.
Call your doctor right away if you feel fainting, dizziness, or a pounding or irregular heartbeat.
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 which were 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 medications known to raise TdP risk; nevertheless, use of 1 drug and of 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 medications 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%); 17% were on ADT combination therapy 3.
Common questions
Can I take Telavancin and Relugolix together?
Combining relugolix and telavancin can add up to a higher risk of a QT-prolonging heart rhythm change, so your care team may monitor your EKG and keep your electrolytes balanced. Tell your pharmacist and doctor you take both, and report any dizziness or palpitations. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Telavancin and Relugolix 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 Telavancin and Relugolix interaction managed?
Keep taking both medicines as prescribed unless your doctor or pharmacist tells you otherwise. Here is how a care team usually handles this: They may decide whether an alternative antibiotic is a better fit, or whether the benefit of relugolix outweighs the risk in your case. If both are needed, they will often check an EKG and your electrolytes (potassium and magnesium) and correct any low levels… 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 Telavancin or Relugolix 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 Telavancin
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