Abametapir and Salmeterol: 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 recordSalmeterol
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 it's applied to your scalp, some of it gets into your body and can briefly slow down a liver enzyme (called CYP3A4) that helps clear out other medicines. Salmeterol (Serevent) is a long-acting inhaler for your lungs, and your body relies on that same enzyme to break it down.
So after using abametapir, salmeterol could build up more than usual, which may raise the chance of side effects like a fast or pounding heartbeat, tremor, or feeling jittery. The good news is this is easy to plan around. Please talk with your pharmacist or doctor before using both so they can time things safely.
Mechanism: Abametapir is a CYP3A4 inhibitor; salmeterol is a CYP3A4 substrate. Inhibition reduces salmeterol clearance, increasing its exposure (AUC/Cmax).
Direction: Increased salmeterol effect and potential for beta-agonist toxicity (tachycardia, QT effects, tremor, hypokalemia).
- Onset: rapid
- Severity: major
- Evidence: theoretical
Management: Avoid CYP3A4 substrates for 2 weeks following topical abametapir application; enzyme inhibition can persist after a single dose. If concurrent use is unavoidable, avoid abametapir. Monitor for enhanced adrenergic effects if co-exposure occurs. Confirm plan with prescriber/pharmacist.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
Within a 2-week window following abametapir application, CYP3A4 substrates should not be used. Should avoiding these substrates not be possible, then abametapir itself should be avoided 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by abametapir
How to manage this interaction
Keep taking your salmeterol inhaler as prescribed, and don't stop either medicine on your own. Because abametapir can raise salmeterol levels for a while after use, timing matters here.
- Tell your pharmacist and prescriber you use salmeterol before starting abametapir lice treatment.
- The documented guidance is to avoid CYP3A4 substrates (like salmeterol) for 2 weeks after applying abametapir; if that isn't feasible, the abametapir itself may be avoided.
- Your care team can pick a safe plan and monitor you more closely if needed.
- Report a racing heart, tremor, or unusual jitteriness.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Abametapir and Salmeterol together?
Abametapir can slow the breakdown of salmeterol, letting it build up and raising the risk of side effects like a fast heartbeat or tremor; the guidance is to avoid salmeterol for 2 weeks after abametapir, so check with your pharmacist or doctor to time it safely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abametapir and Salmeterol 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 Salmeterol interaction managed?
Keep taking your salmeterol inhaler as prescribed, and don't stop either medicine on your own. Because abametapir can raise salmeterol levels for a while after use, timing matters here. Tell your pharmacist and prescriber you use salmeterol before starting abametapir lice treatment. The documented guidance is to avoid CYP3A4 substrates (like salmeterol) for 2 weeks after applying abametapir; if th… 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 Salmeterol 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 Salmeterol
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