Abametapir and Crizotinib: 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 recordCrizotinib
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 block an important liver enzyme called CYP3A4. Crizotinib (Xalkori) is a cancer medicine that this same enzyme breaks down.
When that enzyme is blocked, crizotinib can build up higher than intended in your body. That could mean stronger side effects. This is based on how the drugs work rather than on real patient reports, but it is taken seriously. The good news is your care team can manage this easily, usually by spacing out or avoiding the lice treatment. Talk with your pharmacist or doctor before using both.
Mechanism: Abametapir is a potent inhibitor of CYP3A4. Crizotinib is a CYP3A4 substrate (not a prodrug), so inhibition reduces its clearance and increases systemic exposure (AUC/Cmax).
- Direction: increased crizotinib exposure, greater risk of dose-related toxicity (QT prolongation, hepatotoxicity, bradycardia, vision changes).
- Onset: rapid; enzyme inhibition can persist for up to ~2 weeks after a single topical application.
- Evidence: theoretical, based on PK properties.
- Management: Avoid CYP3A4 substrates for 2 weeks after abametapir application. If crizotinib cannot be interrupted, avoid abametapir and use an alternative lice therapy. Consider closer monitoring if co-exposure occurs.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
Refrain from administering CYP3A4 substrates during the 2-week window following abametapir application. When avoidance of these substrates is not possible, abametapir itself should not be used 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
The main strategy here is avoidance and timing, since abametapir's enzyme-blocking effect can last about 2 weeks after a single application.
- Keep taking your crizotinib (Xalkori) exactly as prescribed. Do not stop or change your cancer medicine on your own.
- Before using abametapir lice lotion, tell your pharmacist or oncologist that you take crizotinib.
- Your care team will usually recommend avoiding the lice product during and for 2 weeks after, or choosing a different lice treatment that does not interact.
- If both must be used, your team may monitor you more closely for side effects.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Crizotinib together?
Abametapir lice lotion can raise crizotinib levels and side effects for up to 2 weeks; do not use both without checking with your oncologist or pharmacist, who will usually pick an alternative lice treatment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Crizotinib 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 Crizotinib interaction managed?
The main strategy here is avoidance and timing, since abametapir's enzyme-blocking effect can last about 2 weeks after a single application. Keep taking your crizotinib (Xalkori) exactly as prescribed. Do not stop or change your cancer medicine on your own. Before using abametapir lice lotion, tell your pharmacist or oncologist that you take crizotinib. Your care team will usually recommend avoidi… 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 Crizotinib 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 Crizotinib
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