Abametapir and Cilostazol: 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
Cilostazol
Abametapir
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.
Here's what's going on. Abametapir is a lotion used to treat head lice. Even though you rub it on your scalp, some of it gets into your body and can briefly block a liver enzyme called CYP3A4. Your blood thinner-type medicine cilostazol (Pletal) is broken down by that same enzyme.
When the enzyme is blocked, cilostazol can build up in your body. That could mean more of its side effects, like headache, a fast or pounding heartbeat, dizziness, or diarrhea. This is based on how the drugs work rather than reports of it happening, but the concern is taken seriously. The good news is your pharmacist or doctor can plan the timing so you stay safe.
Mechanism: Abametapir is a CYP3A4 inhibitor; cilostazol is a CYP3A4 substrate (also CYP2C19). Inhibition reduces cilostazol clearance, increasing its exposure (AUC/Cmax) and the risk of dose-related effects (headache, palpitations, tachycardia, GI upset, hypotension).
- Direction: increased cilostazol effect
- Onset: rapid; inhibition may persist for up to 2 weeks after a single topical application
- Evidence: theoretical
- Management: avoid cilostazol within 2 weeks after applying abametapir; if unavoidable, avoid the abametapir application. Coordinate timing with the care team and monitor for cilostazol-related adverse effects 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, CYP3A4 substrates should not be used. When avoiding these substrates is not possible, then abametapir itself should be avoided1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
What your care team may do:
- Separate these medicines in time, since abametapir's enzyme-blocking effect can last about 2 weeks after it is applied.
- If both are truly needed at the same time, they may reconsider whether the abametapir application should go ahead.
- Watch you more closely for cilostazol side effects (headache, fast or pounding heartbeat, dizziness, diarrhea).
What you should do: Keep taking your cilostazol as prescribed and do not stop anything on your own. Before using an abametapir lice treatment, tell your pharmacist or prescriber you take cilostazol so they can plan the timing.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Cilostazol together?
Abametapir can raise cilostazol levels by blocking the enzyme that clears it, so avoid taking cilostazol within about 2 weeks after an abametapir application. 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 Abametapir and Cilostazol 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 Cilostazol interaction managed?
What your care team may do: Separate these medicines in time, since abametapir's enzyme-blocking effect can last about 2 weeks after it is applied. If both are truly needed at the same time, they may reconsider whether the abametapir application should go ahead. Watch you more closely for cilostazol side effects (headache, fast or pounding heartbeat, dizziness, diarrhea). What you should do: Keep… 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 Cilostazol 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 Cilostazol
Keep reading about Abametapir
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