Suvorexant and Abametapir: 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 recordSuvorexant
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 it goes on your scalp, a little gets into your body and can slow down a liver enzyme (called CYP3A4) that normally helps break down other medicines.
Suvorexant (Belsomra) is a sleep medicine that your body clears using that same enzyme. If the enzyme is slowed, suvorexant can build up in your body. That could make you extra drowsy, groggy the next morning, or unsteady on your feet. The good news is this is easy to plan around. Talk with your pharmacist or doctor about the timing of these two, and they can help you use them safely.
Mechanism: Abametapir inhibits CYP3A4, reducing metabolism of CYP3A4 substrates. Suvorexant is a CYP3A4 substrate (neither drug is a prodrug), so exposure (AUC/Cmax) of suvorexant is expected to rise.
- Direction: Increased suvorexant exposure, enhanced sedation, next-day somnolence, impaired psychomotor performance.
- Onset: Rapid; enzyme inhibition can persist for up to 2 weeks post-application.
- Evidence: Theoretical.
- Management: Avoid CYP3A4 substrates such as suvorexant within 2 weeks after abametapir application. If concurrent use is unavoidable, avoid abametapir.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
Within a 2 week window following administration of abametapir, refrain from using CYP3A4 substrates. Should that not be possible, abametapir itself should not be used 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
Both medicines can be used safely, but timing matters. Here is what a care team typically does:
- Separate them in time. The label advises avoiding CYP3A4 medicines like suvorexant for up to 2 weeks after using abametapir lotion.
- Choose one approach. If you cannot pause your sleep medicine, your care team may hold off on the abametapir lice treatment instead.
- Watch for extra drowsiness. Report unusual morning grogginess or unsteadiness.
Keep taking your medicines as prescribed and do not stop anything on your own. Ask your pharmacist or prescriber to help you plan the timing before you start the lice treatment.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Suvorexant and Abametapir together?
Abametapir can raise suvorexant levels and increase drowsiness, so avoid the sleep medicine for up to 2 weeks after using the lice lotion, or skip the lotion if that is not possible. Check with your pharmacist or doctor to plan the timing. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Suvorexant and Abametapir 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 Suvorexant and Abametapir interaction managed?
Both medicines can be used safely, but timing matters. Here is what a care team typically does: Separate them in time. The label advises avoiding CYP3A4 medicines like suvorexant for up to 2 weeks after using abametapir lotion. Choose one approach. If you cannot pause your sleep medicine, your care team may hold off on the abametapir lice treatment instead. Watch for extra drowsiness. Report unusu… 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 Suvorexant or Abametapir 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 Suvorexant
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