Abametapir and Vorapaxar: 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 recordVorapaxar
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 on the scalp to treat head lice. Even though it goes on your skin, a little can get into your body and briefly block an enzyme called CYP3A4. That enzyme is one of the main ways your body breaks down vorapaxar (Zontivity), a blood thinner used to help prevent clots.
With that enzyme slowed down, vorapaxar can build up in your blood, which could raise your risk of bleeding or bruising. The good news is this is easy to plan around. Your pharmacist or doctor can look at the timing of your lice treatment and your blood thinner and keep you safe.
Mechanism: Abametapir inhibits CYP3A4. Vorapaxar is a CYP3A4 substrate (and not a prodrug requiring activation), so inhibition reduces its metabolism and increases exposure (higher AUC/Cmax).
Direction/effect: Increased vorapaxar exposure, with potential for enhanced antiplatelet effect and bleeding risk.
- Onset: rapid
- Evidence: theoretical (based on CYP3A4 inhibition data)
- Severity: major
Management: Avoid CYP3A4 substrates, including vorapaxar, within 2 weeks after a single abametapir application. If concurrent use is unavoidable, avoid abametapir. Monitor for signs of bleeding.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
For a period of 2 weeks following application of abametapir, refrain from using CYP3A4 substrates. Should this not be 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 usually be handled with good timing and communication with your care team.
- Keep taking your vorapaxar (Zontivity) as prescribed unless your doctor or pharmacist tells you otherwise.
- Tell your pharmacist or prescriber before using abametapir lice lotion, since its effect on the drug-clearing enzyme can last up to 2 weeks after a single application.
- Your team may space out the lice treatment, choose a different lice option, or watch you more closely during that window.
- Report any unusual bruising, bleeding, dark stools, or bleeding gums right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Vorapaxar together?
Abametapir can slow the breakdown of vorapaxar for up to 2 weeks, raising its levels and bleeding risk, so check with your pharmacist or doctor before using the lice lotion. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Vorapaxar 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 Vorapaxar interaction managed?
Both of these can usually be handled with good timing and communication with your care team. Keep taking your vorapaxar (Zontivity) as prescribed unless your doctor or pharmacist tells you otherwise. Tell your pharmacist or prescriber before using abametapir lice lotion, since its effect on the drug-clearing enzyme can last up to 2 weeks after a single application. Your team may space out the lice… 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 Vorapaxar 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 Vorapaxar
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