Ethinyl Estradiol and Avapritinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ethinyl Estradiol
No brand names on recordAvapritinib
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.
What happens
Increased ethinyl estradiol exposure and an increased risk of ethinyl estradiol-related adverse reactions
Interaction Deep Dive
Coadministration of avapritinib with ethinyl estradiol-containing contraceptives may increase the exposure of ethinyl estradiol, which may lead to increased risk of ethinyl estradiol-associated adverse reactions. In a drug-drug interaction study of 15 subjects, coadministration of avapritinib 25 mg once daily with an oral contraceptive (levonorgestrel 0.15 mg/ethinyl estradiol 0.03 mg) resulted in a mean ethinyl estradiol AUC ratio of 1.15 (90% CI, 1.04, 1.28) and a mean ethinyl estradiol Cmax ratio of 1.46 (90% CI, 1.17, 1.81) relative to participants administered the oral contraceptive alone. This increase in ethinyl estradiol Cmax may lead to an increased risk of ethinyl estradiol-related adverse events. If the patient is unable to use or tolerate an effective non-hormonal contraceptive or an effective hormonal contraceptive without estrogen, use a formulation of ethinyl estradiol containing 20 mcg or less unless a higher dose is necessary1.
Why it happens (mechanism)
Unknown
Literature reports
1 report — tap to read
a) In a drug-drug interaction study of 15 subjects, coadministration of avapritinib 25 mg once daily with an oral contraceptive (levonorgestrel 0.15 mg/ethinyl estradiol 0.03 mg) resulted in a mean ethinyl estradiol AUC ratio of 1.15 (90% CI, 1.04, 1.28) and a mean ethinyl estradiol Cmax ratio of 1.46 (90% CI, 1.17, 1.81) relative to participants administered the oral contraceptive alone. This increase in ethinyl estradiol Cmax may lead to an increased risk of ethinyl estradiol-related adverse events 1.
Common questions
Can I take Ethinyl Estradiol and Avapritinib together?
Increased ethinyl estradiol exposure and an increased risk of ethinyl estradiol-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ethinyl Estradiol and Avapritinib interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Ethinyl Estradiol or Avapritinib 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: AYVAKIT(TM) oral tablets, avapritinib oral tablets. Blueprint Medicines Corporation (per manufacturer), Cambridge, MA, 2024. DailyMed
Keep reading about Ethinyl Estradiol
Keep reading about Avapritinib
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist