Maraviroc 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
Maraviroc
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.
Here's what's going on. Maraviroc (Selzentry) is broken down in your body by an enzyme called CYP3A4. The Cobenfy combination contains xanomeline, which can briefly slow that enzyme down in your gut. When it does, your body may clear maraviroc a little more slowly, so more of it can build up.
In plain terms, that could mean a stronger dose effect from maraviroc and a higher chance of side effects like dizziness, headache, or an upset stomach. This is based on theoretical reasoning, not strong real-world reports, so try not to worry. Keep taking both exactly as prescribed and let your pharmacist or doctor know how you're feeling.
Mechanism: Xanomeline (in Cobenfy) transiently inhibits intestinal CYP3A4. Maraviroc is a sensitive CYP3A4 substrate, so gut-level inhibition may increase maraviroc oral bioavailability and systemic exposure (AUC/Cmax), raising the risk of dose-related adverse effects.
Direction: Increased maraviroc effect (neither drug is a prodrug requiring activation).
- Magnitude: not quantified.
- Onset: unspecified.
- Evidence: theoretical.
- Management: Monitor for increased frequency/severity of maraviroc-related adverse reactions (orthostatic hypotension, dizziness, hepatotoxicity signs, GI effects). Dose may be individualized by the care team if warranted.
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 transient, local inhibition of CYP3A4, without affecting the enzyme systemically. When it is taken together with oral medications that are sensitive substrates of CYP3A4, the exposure to those oral CYP3A4 sensitive substrates may rise. As a result, adverse reactions from these substrates could occur more often and/or more severely. Should the two be administered together, watch patients for an increase in the frequency and/or severity of adverse reactions associated with oral drugs that are sensitive substrates of CYP3A41.
Why it happens (mechanism)
Inhibition of CYP3A4-substrate metabolism by xanomeline
How to manage this interaction
The good news: this is a manageable interaction, and your care team has clear options.
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may watch you more closely for maraviroc side effects such as dizziness, lightheadedness on standing, headache, or stomach upset.
- If side effects appear, your maraviroc dose may be adjusted and individualized by your care team.
What to do: Tell your pharmacist or prescriber that you take both medicines, and report any new or worsening symptoms so they can tailor your plan.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Maraviroc and Trospium / Xanomeline together?
Cobenfy (xanomeline) can briefly slow how your gut breaks down maraviroc, so more maraviroc may build up and side effects could increase; this is theoretical, so keep taking both as prescribed and report any new symptoms so your team can monitor and adjust if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Maraviroc 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 Maraviroc and Trospium / Xanomeline interaction managed?
The good news: this is a manageable interaction, and your care team has clear options. Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may watch you more closely for maraviroc side effects such as dizziness, lightheadedness on standing, headache, or stomach upset. If side effects appear, your maraviroc dose may be adjusted and individualized by your c… 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 Maraviroc 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 Maraviroc
Keep reading about Trospium / Xanomeline
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