Drug interactions
Desogestrel-ethinyl estradiol + Fostemsavir
Severity: Moderate
Desogestrel-ethinyl estradiol and Fostemsavir: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Fostemsavir's active form raises ethinyl estradiol exposure. Higher estrogen levels may increase estrogen-related adverse effects including thromboembolic risk.
What this interaction means in plain words
Desogestrel-ethinyl estradiol and Fostemsavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Desogestrel-ethinyl estradiol belongs to Endocrine; Fostemsavir belongs to Anti Virals.
Why it happens
Temsavir inhibits BCRP and possibly other pathways, reducing ethinyl estradiol clearance.
What to do
Keep the ethinyl estradiol dose at or below 30 mcg per day, as labeling advises. Monitor for estrogenic adverse effects and consider a lower-estrogen or non-estrogen method.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Desogestrel-ethinyl estradiol and Fostemsavir, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Desogestrel-ethinyl estradiol
- Desogestrel-ethinyl estradiol + Fezolinetant Contraindicated
- Aminocaproic acid + Desogestrel-ethinyl estradiol Major
- Amobarbital + Desogestrel-ethinyl estradiol Major
- Anastrozole + Desogestrel-ethinyl estradiol Major
- Apalutamide + Desogestrel-ethinyl estradiol Major
- Atazanavir + Desogestrel-ethinyl estradiol Major
Other interactions of Fostemsavir
- Apalutamide + Fostemsavir Contraindicated
- Carbamazepine + Fostemsavir Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Fostemsavir + Phenytoin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Desogestrel-ethinyl estradiol with Fostemsavir?
MediHelp rates the interaction as moderate. Desogestrel-ethinyl estradiol and Fostemsavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Fostemsavir's active form raises ethinyl estradiol exposure. Higher estrogen levels may increase estrogen-related adverse effects including thromboembolic risk.
How serious is the interaction between Desogestrel-ethinyl estradiol and Fostemsavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Keep the ethinyl estradiol dose at or below 30 mcg per day, as labeling advises. Monitor for estrogenic adverse effects and consider a lower-estrogen or non-estrogen method.
What other medicines interact with Desogestrel-ethinyl estradiol?
MediHelp also lists interactions of Desogestrel-ethinyl estradiol with, for example, Fezolinetant, Aminocaproic acid, Amobarbital. The full list is on the Desogestrel-ethinyl estradiol page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
