Abametapir and Ranolazine: 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 recordRanolazine
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 gets into your body and can briefly slow down a liver enzyme called CYP3A4. That enzyme is one of the main ways your body breaks down ranolazine (Ranexa), your heart medicine.
If that enzyme is slowed, ranolazine can build up higher than usual. Ranolazine can affect your heart's rhythm, so higher levels are something to take seriously. The good news is this is easy to plan around. Talk with your pharmacist or doctor before using the lice lotion so your care team can guide the timing safely.
Mechanism: Abametapir inhibits CYP3A4. Ranolazine is a CYP3A4 substrate (and is itself sensitive to 3A4 inhibition, with QT prolongation being dose/exposure dependent), so co-exposure increases ranolazine AUC/Cmax.
- Direction: increased ranolazine exposure and effect (neither is a prodrug here).
- Onset: rapid; inhibition may persist ~2 weeks after a single topical application.
- Evidence: theoretical.
- Concern: elevated ranolazine levels raise QT-prolongation risk.
Management: Avoid CYP3A4 substrates such as ranolazine for 2 weeks after abametapir application; if unavoidable, avoid abametapir. Consider ECG/symptom monitoring if co-exposure occurs.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
For a period of 2 weeks following the application of abametapir, refrain from administering CYP3A4 substrates. Should avoiding these substrates not be possible, then abametapir itself should not be used 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
Keep taking your ranolazine as prescribed. The main issue is the lice lotion, abametapir, which can raise ranolazine levels for about 2 weeks after a single use.
- Before using abametapir, tell your pharmacist or prescriber you take ranolazine.
- The documented advice is to avoid CYP3A4 substrates like ranolazine for 2 weeks after applying abametapir. If that isn't practical, the alternative is to avoid abametapir and use a different lice treatment.
- Your care team can help you choose the safest option and may monitor you more closely if both are needed.
Do not stop or change either medicine on your own.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Ranolazine together?
Abametapir can raise ranolazine levels for up to 2 weeks by blocking CYP3A4, which may increase heart-rhythm risk, so ask your pharmacist or doctor to help you time or avoid the lice lotion. Do not change either medicine on your own. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Ranolazine 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 Ranolazine interaction managed?
Keep taking your ranolazine as prescribed. The main issue is the lice lotion, abametapir, which can raise ranolazine levels for about 2 weeks after a single use. Before using abametapir, tell your pharmacist or prescriber you take ranolazine. The documented advice is to avoid CYP3A4 substrates like ranolazine for 2 weeks after applying abametapir. If that isn't practical, the alternative is to avo… 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 Ranolazine 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 Ranolazine
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