Relugolix and Dronedarone: 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
Dronedarone
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 be a risky combination, which is why doctors generally avoid using them together. Dronedarone (Multaq) is a heart rhythm drug, and relugolix (Orgovyx) is used for certain hormone-related conditions. Both can affect your heart's electrical rhythm in a way called QT prolongation, and using them together adds those effects up. That can raise the chance of a dangerous, fast heartbeat.
On top of that, dronedarone can cause more relugolix to build up in your body, which may increase relugolix side effects. The good news is your care team knows how to handle this. Please don't stop or change either medicine on your own. Just talk with your doctor or pharmacist so they can guide you safely.
Direction: Dronedarone increases relugolix exposure and adds to QT prolongation risk.
- Mechanism: Dronedarone inhibits P-gp, reducing efflux of the P-gp substrate relugolix, increasing its exposure; additive QT-interval prolongation from both agents.
- Risk: Potential for torsade de pointes-type ventricular tachycardia.
- Severity/evidence: Contraindicated; substantiation is theoretical.
- Management: Avoid coadministration. If unavoidable, give relugolix first, separate doses by at least 6 hours, and monitor for adverse reactions more frequently. Relugolix may be interrupted up to 2 weeks for short P-gp inhibitor courses; if interrupted >7 days, restart with a 360 mg loading dose then 120 mg daily.
What happens
Increased relugolix exposure and an increased risk of QT interval prolongation
Interaction Deep Dive
Because of the possibility of torsade de pointes-type ventricular tachycardia, dronedarone must not be given together with agents that prolong the QT interval, including relugolix2. Since relugolix is a substrate of P-gp and dronedarone acts as a P-gp inhibitor, combining the two can raise relugolix exposure, thereby heightening the likelihood of relugolix-related adverse reactions. When their combined use cannot be avoided, give relugolix first, allow a gap of no less than 6 hours between doses, and increase how often adverse reactions are monitored. For a brief course involving certain P-gp inhibitors, relugolix therapy may be paused for as long as 2 weeks. Once the P-gp inhibitor has been stopped, relugolix can be resumed. Should relugolix be withheld for more than 7 days, reinitiate it with a 360 mg loading dose on day one, followed by 120 mg once daily thereafter1.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of relugolix; additive QT interval prolongation
How to manage this interaction
Because this pair is flagged as one to avoid, your care team will usually choose an alternative or hold one drug when possible. Keep taking both exactly as prescribed until you have spoken with them.
- Tell your pharmacist and prescriber that you are on (or considering) both medicines.
- If they must be used together, the plan may include giving relugolix first, separating doses by at least 6 hours, and monitoring you more closely for side effects.
- Your relugolix may be paused during a short course of dronedarone; restarting has specific dosing your team will manage.
- Report any dizziness, fainting, or heart palpitations promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Relugolix and Dronedarone together?
Combining dronedarone and relugolix is generally contraindicated because it can raise relugolix levels and add to the risk of a dangerous heart rhythm; do not change either drug yourself and speak with your care team. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Dronedarone interaction?
It is rated contraindicated. These should generally not be used together.
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 Dronedarone interaction managed?
Because this pair is flagged as one to avoid, your care team will usually choose an alternative or hold one drug when possible. Keep taking both exactly as prescribed until you have spoken with them. Tell your pharmacist and prescriber that you are on (or considering) both medicines. If they must be used together, the plan may include giving relugolix first, separating doses by at least 6 hours, a… 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 Dronedarone 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 (2)
Keep reading about Dronedarone
Keep reading about Relugolix
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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