Lumefantrine and Trospium / Xanomeline: 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 recordTrospium / Xanomeline
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.
What's going on: Lumefantrine (part of an antimalaria medicine) can slow down a liver enzyme called CYP2D6. Some medicines are broken down by that enzyme, so if you take them together, those medicines can build up in your body and cause more side effects than usual.
On top of that, both drugs can affect your heart's rhythm (a change on the ECG called QT prolongation), and combining them may add to that effect. This concern is based on how the drugs work rather than lots of real-world reports, but it is taken seriously. Please don't change anything on your own. Your pharmacist or doctor can look at your specific medicines and keep you safe.
Mechanism: Lumefantrine (with artemether) inhibits CYP2D6, reducing metabolism of CYP2D6 substrates and increasing their exposure (AUC/Cmax), raising the risk of dose-related adverse effects. Both agents also carry QT-prolongation potential, so the combination may be additive on the QT interval.
- Direction: Increased substrate exposure (neither drug here is a prodrug requiring CYP2D6 activation).
- Onset: Unspecified.
- Evidence: Theoretical.
- Severity: Major.
- Management: Avoid coadministration where possible; if used together, obtain baseline and follow-up ECGs, monitor electrolytes, and watch for substrate toxicity. Doses should be individualized by the care team.
What happens
Increased CYP2D6 substrate exposure and an increased risk of CYP2D6 substrate-related adverse reactions
Interaction Deep Dive
Avoid giving artemether/lumefantrine together with CYP2D6 substrates, because doing so could produce an additive effect on the QT interval, substantially raise exposure to the CYP2D6 substrates, and heighten the likelihood of adverse effects. For this reason, watch for prolongation of the QT interval1.
Why it happens (mechanism)
Inhibition of CYP2D6-substrate metabolism by artemether/lumefantrine
How to manage this interaction
What your care team may do:
- Prefer to avoid using these together when there is a reasonable alternative.
- If both are needed, they may check your heart rhythm with an ECG and watch your electrolytes.
- They may monitor you more closely for side effects, and any affected medicine's dose may be adjusted and individualized to you.
What you should do: Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Tell your pharmacist or doctor about all your medicines, and report symptoms like fainting, dizziness, palpitations, or a racing/irregular heartbeat right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Lumefantrine and Trospium / Xanomeline together?
Combining lumefantrine with a CYP2D6 substrate can raise that drug's levels and add to QT-prolongation risk, so this pairing is usually avoided. Don't change anything yourself; ask your pharmacist or doctor to review it. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lumefantrine and Trospium / Xanomeline 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 Lumefantrine and Trospium / Xanomeline interaction managed?
What your care team may do: Prefer to avoid using these together when there is a reasonable alternative. If both are needed, they may check your heart rhythm with an ECG and watch your electrolytes. They may monitor you more closely for side effects, and any affected medicine's dose may be adjusted and individualized to you. What you should do: Keep taking both exactly as prescribed unless your pr… 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 Lumefantrine or Trospium / Xanomeline 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 (1)
- 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 Trospium / Xanomeline
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist