Drug interactions
Atazanavir + Estradiol
Severity: Moderate
Atazanavir and Estradiol: 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
Ritonavir- or cobicistat-boosted atazanavir regimens can change estrogen exposure, and unboosted atazanavir may raise ethinyl estradiol levels. The net effect on estradiol can be an increase or decrease, so hormone therapy may be less effective or cause more estrogenic adverse effects.
What this interaction means in plain words
Atazanavir and Estradiol 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.
Atazanavir belongs to Anti Virals; Estradiol belongs to Endocrine.
Why it happens
Atazanavir inhibits CYP3A4 and UGT1A1, while the boosting agent may induce glucuronidation, giving variable effects on estradiol clearance.
What to do
Monitor symptom control and estrogen adverse effects such as breast tenderness, and adjust the estradiol dose accordingly. For contraception, choose a method that does not depend on oral estrogen.
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?
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Other interactions of Estradiol
- Anastrozole + Estradiol Contraindicated
- Estradiol + Fezolinetant Contraindicated
- Estradiol + Ospemifene Contraindicated
- Antithrombin alfa + Estradiol Major
- Antithrombin iii + Estradiol Major
- Estradiol + Exemestane Major
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Estradiol?
MediHelp rates the interaction as moderate. Atazanavir and Estradiol 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. Ritonavir- or cobicistat-boosted atazanavir regimens can change estrogen exposure, and unboosted atazanavir may raise ethinyl estradiol levels. The net effect on estradiol can be an increase or decrease, so hormone therapy may be less effective or cause more estrogenic adverse effects.
How serious is the interaction between Atazanavir and Estradiol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor symptom control and estrogen adverse effects such as breast tenderness, and adjust the estradiol dose accordingly. For contraception, choose a method that does not depend on oral estrogen.
What other medicines interact with Estradiol?
MediHelp also lists interactions of Estradiol with, for example, Anastrozole, Fezolinetant, Ospemifene. The full list is on the Estradiol page.
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