Midostaurin 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
Midostaurin
Trospium / 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.
You've been prescribed midostaurin (Rydapt), a cancer medicine, along with Cobenfy, which contains xanomeline and trospium. The xanomeline part can briefly slow down an enzyme in your gut called CYP3A4, the same enzyme that helps break down midostaurin after you swallow it.
When that enzyme is slowed, a bit more midostaurin may be absorbed. That could make its side effects (like nausea, tiredness, or low blood counts) show up more often or feel stronger. This concern is theoretical, meaning it's based on how the drugs work rather than reported problems. The good news is your care team can watch for this and adjust things if needed. Keep taking both exactly as prescribed and share any new symptoms.
Effect: Xanomeline (in Cobenfy) may increase exposure to midostaurin, a sensitive oral CYP3A4 substrate, raising the frequency/severity of midostaurin-related adverse effects.
Mechanism: Xanomeline transiently inhibits enteric (gut) CYP3A4, not systemic CYP3A4, reducing first-pass metabolism and increasing substrate AUC.
- Direction: Increased midostaurin exposure (neither drug is a prodrug relevant here).
- Onset: Unspecified.
- Evidence: Theoretical.
- Magnitude: Not quantified.
Management: Monitor for increased midostaurin toxicity (GI effects, cytopenias, QT prolongation, fatigue). Dose may need individualization by the oncology team.
What happens
Increased oral sensitive CYP3A4 substrate exposure and an increased risk on severity and frequency of sensitive CYP3A4 substrate-related adverse reactions
Interaction Deep Dive
In the gut, xanomeline produces a temporary, localized inhibition of CYP3A4 without affecting the enzyme systemically. When xanomeline is taken together with oral medications that are sensitive substrates of CYP3A4, the exposure to those oral sensitive CYP3A4 substrates may rise. As a result, adverse reactions associated with these substrates may occur more often and/or become more severe. For patients receiving both agents together, watch for any increase in the frequency and/or severity of adverse reactions linked to oral drugs that are sensitive substrates of CYP3A41.
Why it happens (mechanism)
Inhibition of CYP3A4-substrate metabolism by xanomeline
How to manage this interaction
This interaction can usually be managed. Here's what typically happens and what you can do:
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your care team may monitor you more closely for midostaurin side effects such as nausea, vomiting, fatigue, or changes in blood counts.
- Your midostaurin dose may need to be adjusted and individualized by your oncology team if side effects increase.
- Report any new or worsening symptoms promptly.
Because this concern is theoretical, it's mainly about watchfulness. Ask your pharmacist if you have questions about timing or symptoms to watch for.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Midostaurin and Trospium / Xanomeline together?
Taking Cobenfy with midostaurin may modestly raise midostaurin levels and side effects because xanomeline briefly slows a gut enzyme; keep taking both as prescribed and watch for increased midostaurin side effects, letting your care team adjust and monitor as needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Midostaurin and Trospium / Xanomeline interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Midostaurin and Trospium / Xanomeline interaction managed?
This interaction can usually be managed. Here's what typically happens and what you can do: Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your care team may monitor you more closely for midostaurin side effects such as nausea, vomiting, fatigue, or changes in blood counts. Your midostaurin dose may need to be adjusted and individualized by your oncology team… 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 Midostaurin 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 anything you'd monitor while I'm on both?
References (1)
- Citation #1
Keep reading about Midostaurin
Keep reading about Trospium / Xanomeline
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