Relugolix and Lumefantrine: 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
Lumefantrine
No brand names on recordRelugolix
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.
You've been prescribed relugolix (Orgovyx) for prostate cancer, and you may also take artemether/lumefantrine to treat or prevent malaria. There are two things worth knowing. First, relugolix can speed up how your body breaks down the malaria medicine, which could make it work less well against the infection. Second, both medicines can affect your heart's rhythm (the QT interval), and together that effect can add up.
This is based on how the drugs are expected to behave, not on confirmed cases, so please don't panic. Keep taking both exactly as prescribed and let your care team know you're on both. They can watch you closely and manage this safely.
Direction: Relugolix is a CYP3A4 inducer and may increase metabolism of artemether/lumefantrine, lowering their systemic exposure and risking reduced antimalarial efficacy. Neither is activated by this pathway here, so induction reduces effect.
Additive risk: Both agents prolong the QT interval; coadministration may be additive.
- Evidence: theoretical; onset unspecified; severity major.
- Management: Weigh benefit of ADT in patients with congenital long QT, CHF, electrolyte abnormalities, or other QT-prolonging drugs. Correct electrolytes; consider periodic ECG and electrolyte monitoring. Watch for malaria treatment failure.
What happens
Reduced artemether/lumefantrine exposure, reduced efficacy of artemether/lumefantrine, loss of antimalarial efficacy and an increased risk of QT interval prolongation
Interaction Deep Dive
Use caution when combining artemether/lumefantrine with relugolix, which is a CYP3A4 inducer, because this combination can lower exposure to artemether/lumefantrine and thereby diminish its efficacy2. Because artemether/lumefantrine prolongs the QT interval, giving relugolix alongside it may produce additive QT interval effects. In patients who have congenital long QT syndrome, congestive heart failure, or recurrent electrolyte disturbances, as well as those receiving other agents known to prolong the QT interval, weigh whether the benefits of androgen deprivation therapy such as relugolix justify the potential risks. Any electrolyte abnormalities should be corrected, and periodic ECG and electrolyte monitoring should be considered1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of artemether/lumefantrine; additive QT interval prolongation
How to manage this interaction
Both medicines are important, so the usual approach is to keep taking them as prescribed while your care team keeps a closer eye on you.
- Tell your prescriber and pharmacist you take both drugs so they can weigh the benefits of your cancer therapy against the risks.
- Your team may check your electrolytes (like potassium and magnesium) and correct any imbalances, and may do periodic ECGs to watch your heart rhythm.
- They may also watch to make sure the malaria treatment is actually working, since its effect could be weakened.
- Report symptoms like fainting, palpitations, dizziness, or a returning fever right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Relugolix and Lumefantrine together?
Relugolix may lower the malaria drug's effectiveness and both can affect heart rhythm, so keep taking both as prescribed and let your care team monitor your electrolytes, ECG, and malaria response. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Relugolix and Lumefantrine 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 Lumefantrine interaction managed?
Both medicines are important, so the usual approach is to keep taking them as prescribed while your care team keeps a closer eye on you. Tell your prescriber and pharmacist you take both drugs so they can weigh the benefits of your cancer therapy against the risks. Your team may check your electrolytes (like potassium and magnesium) and correct any imbalances, and may do periodic ECGs to watch you… 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 Lumefantrine 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)
- Product Information: ORGOVYX oral tablets, relugolix oral tablets. Sumitomo Pharma America, Inc (per FDA), Marlborough, MA, 2025. DailyMed
- Product Information: COARTEM® oral tablets, artemether lumefantrine oral tablets. Novartis Pharmaceuticals Corporation (per DailyMed), East Hanover, NJ, 2025. DailyMed
Keep reading about Lumefantrine
Keep reading about Relugolix
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major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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