Belumosudil and Artemether: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 15, 2026 · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Artemether
No brand names on recordBelumosudil
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 affect each other by working on the same liver pathway (an enzyme called CYP3A4). Belumosudil (Rezurock) can slow the breakdown of your malaria medicine artemether, so more of it may build up in your body. That matters because artemether can affect your heart's rhythm (a change called QT prolongation), and higher levels may raise that risk. At the same time, artemether may speed up how your body clears belumosudil, which could make belumosudil work less well.
The good news is this concern is based on theory, not on confirmed reports. Your care team can manage it by watching you more closely, so please tell your pharmacist or doctor you take both.
Effect: Bidirectional CYP3A4 interaction. Belumosudil (a CYP3A4 substrate and inhibitor) may inhibit metabolism of artemether/lumefantrine, increasing their exposure and the risk of QT prolongation. Conversely, artemether/lumefantrine may induce CYP3A4, reducing belumosudil exposure and efficacy.
- Mechanism: CYP3A4 inhibition (raised antimalarial levels) plus CYP3A4 induction (lowered belumosudil levels).
- Evidence: Theoretical; magnitude and onset unspecified.
- Management: Use with caution. Consider ECG/QT monitoring and correction of electrolytes (K+, Mg2+) during the short antimalarial course; watch for reduced belumosudil efficacy.
What happens
Increased artemether/lumefantrine exposure, an increased risk of QT prolongation, reduced CYP3A4 substrate exposure and reduced efficacy of CYP3A4 substrate
Interaction Deep Dive
Caution is warranted when artemether/lumefantrine is given together with agents that act as both CYP3A4 inhibitors and CYP3A4 substrates, because such coadministration can raise artemether/lumefantrine exposure, thereby heightening the potential for QT interval prolongation, while also lowering exposure to the CYP3A4 substrates1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of artemether/lumefantrine; induction of CYP3A4-substrate metabolism by artemether/lumefantrine
How to manage this interaction
Keep taking both exactly as prescribed unless your care team tells you otherwise. Because these medicines can influence each other through the same liver enzyme, your team may take a few practical steps:
- Watch you more closely for heart-rhythm changes (they may check an ECG and your electrolytes) while you are on the malaria treatment.
- Keep an eye on whether your belumosudil is still working as expected, since its levels could drop.
- Adjust and individualize your plan if needed.
Tell your pharmacist or doctor that you take both, and report any dizziness, fainting, or palpitations right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Belumosudil and Artemether together?
Combining artemether with belumosudil may raise artemether levels (increasing QT-prolongation risk) while possibly lowering belumosudil's effectiveness; the concern is theoretical, so let your care team know so they can monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Belumosudil and Artemether 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 Belumosudil and Artemether interaction managed?
Keep taking both exactly as prescribed unless your care team tells you otherwise. Because these medicines can influence each other through the same liver enzyme, your team may take a few practical steps: Watch you more closely for heart-rhythm changes (they may check an ECG and your electrolytes) while you are on the malaria treatment. Keep an eye on whether your belumosudil is still working as ex… 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 Belumosudil or Artemether 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 Artemether
Keep reading about Belumosudil
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