Abametapir and Rolapitant: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Abametapir
No brand names on recordRolapitant
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.
Abametapir is a lotion used to treat head lice. Even though you only put it on your scalp, a little can get into your body and briefly slow down a liver enzyme (called CYP3A4) that helps clear certain medicines. Rolapitant (Varubi) is one of those medicines, used to prevent nausea from chemotherapy.
When this enzyme is slowed, rolapitant can build up more than expected, which may raise the chance of side effects. This is based on how the drugs work rather than reports of actual harm, but it is taken seriously. The good news is your care team can plan the timing so both are used safely.
Mechanism: Abametapir is a CYP3A4 inhibitor; topical application can inhibit CYP3A4-mediated metabolism of substrates such as rolapitant, increasing systemic exposure (AUC/Cmax).
- Direction: Increased rolapitant exposure and potential for enhanced/prolonged effects.
- Onset: Rapid; enzyme inhibition can persist for approximately 2 weeks post-application.
- Evidence: Theoretical, based on known PK properties.
- Severity: Major.
Management: Avoid CYP3A4 substrates, including rolapitant, within 2 weeks after abametapir application. If concurrent use is unavoidable, avoid abametapir. Neither agent requires prodrug activation here.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
For a period of 2 weeks following abametapir application, refrain from using CYP3A4 substrates. When avoiding these substrates is not possible, do not use abametapir1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
Both of these can be used safely with the right timing plan from your care team.
- Keep taking your medicines as prescribed and let your pharmacist and doctors know you have used or may use abametapir lice lotion.
- The main strategy is timing: substrates like rolapitant are generally avoided within about 2 weeks after applying abametapir.
- If that separation is not workable, your team may choose to avoid the abametapir treatment instead.
- Your care team can individualize this and monitor you more closely if the two overlap.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Rolapitant together?
Abametapir can raise rolapitant levels by slowing its breakdown, so avoid rolapitant within about 2 weeks after using abametapir lotion; let your care team choose the timing. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Rolapitant interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How is the Abametapir and Rolapitant interaction managed?
Both of these can be used safely with the right timing plan from your care team. Keep taking your medicines as prescribed and let your pharmacist and doctors know you have used or may use abametapir lice lotion. The main strategy is timing: substrates like rolapitant are generally avoided within about 2 weeks after applying abametapir. If that separation is not workable, your team may choose to av… 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 Abametapir or Rolapitant 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: XEGLYZE(TM) topical lotion, abametapir topical lotion. Dr Reddy’s Laboratories Inc (per FDA), Princeton, NJ, 2020. DailyMed
Keep reading about Abametapir
Keep reading about Rolapitant
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