Abametapir and Lopinavir: 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 recordLopinavir
No brand names on record
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 put it on your scalp, a little can get into your body and briefly slow down a liver enzyme called CYP3A4. That enzyme is one of the main ways your body breaks down lopinavir, an HIV medicine.
When that enzyme is slowed, lopinavir can build up higher than normal, which may lead to more side effects. This effect can last for up to two weeks after you use the lotion. The good news is this is manageable. Please talk with your pharmacist or doctor before using abametapir so your care team can plan the safest timing for you.
Effect: Abametapir inhibits CYP3A4, reducing metabolism of the CYP3A4 substrate lopinavir and increasing its systemic exposure (higher AUC/Cmax). Onset is rapid and inhibition can persist for roughly 2 weeks post-application.
- Direction: Increased lopinavir exposure and potential for greater concentration-related adverse effects (GI, metabolic, QT-related considerations).
- Evidence: Theoretical; severity rated major.
- Management: Avoid CYP3A4 substrates within 2 weeks after abametapir application. If concomitant use is unavoidable, avoid abametapir. Consider alternative lice therapy and closer clinical monitoring if exposure occurs.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
For a period of two weeks following abametapir application, refrain from administering CYP3A4 substrates. Should that be impractical, abametapir itself should not be used 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
This interaction is manageable with planning. Keep taking your lopinavir as prescribed and do not stop it on your own.
- Before using abametapir, tell your pharmacist or prescriber that you take lopinavir.
- The guidance on file is to avoid CYP3A4 substrates like lopinavir for 2 weeks after applying abametapir. If that is not possible, the abametapir treatment itself should be avoided.
- Your care team may suggest an alternative lice treatment instead.
- Report any new or stronger side effects so your team can monitor you more closely.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Lopinavir together?
Abametapir can raise lopinavir levels by blocking CYP3A4 for up to two weeks, so check with your pharmacist or doctor before using it; they may recommend a different lice treatment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Lopinavir 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 Lopinavir interaction managed?
This interaction is manageable with planning. Keep taking your lopinavir as prescribed and do not stop it on your own. Before using abametapir, tell your pharmacist or prescriber that you take lopinavir. The guidance on file is to avoid CYP3A4 substrates like lopinavir for 2 weeks after applying abametapir. If that is not possible, the abametapir treatment itself should be avoided. Your care 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 Abametapir or Lopinavir 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 Lopinavir
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