Drug interactions
Atazanavir + Ethinyl estradiol-levonorgestrel
Severity: Major
Atazanavir and Ethinyl estradiol-levonorgestrel: major 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
Atazanavir increases ethinyl estradiol and progestin exposure, which can raise estrogen-related adverse effects. When given with ritonavir, ethinyl estradiol exposure may be lowered instead, risking reduced efficacy.
What this interaction means in plain words
Atazanavir and Ethinyl estradiol-levonorgestrel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Atazanavir belongs to Anti Virals; Ethinyl estradiol-levonorgestrel belongs to Endocrine.
Why it happens
Atazanavir inhibits CYP3A4 and UGT1A1, while ritonavir boosting adds induction, altering hormone levels.
What to do
Use an alternative or additional nonhormonal contraceptive method. If combined with atazanavir without ritonavir, keep ethinyl estradiol dose at the lowest effective level.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Ethinyl estradiol-levonorgestrel
- Ethinyl estradiol-levonorgestrel + Fezolinetant Contraindicated
- Ethinyl estradiol-levonorgestrel + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-levonorgestrel + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-levonorgestrel Major
- Amobarbital + Ethinyl estradiol-levonorgestrel Major
- Anastrozole + Ethinyl estradiol-levonorgestrel 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 Ethinyl estradiol-levonorgestrel?
MediHelp rates the interaction as major. Atazanavir and Ethinyl estradiol-levonorgestrel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Atazanavir increases ethinyl estradiol and progestin exposure, which can raise estrogen-related adverse effects. When given with ritonavir, ethinyl estradiol exposure may be lowered instead, risking reduced efficacy.
How serious is the interaction between Atazanavir and Ethinyl estradiol-levonorgestrel?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use an alternative or additional nonhormonal contraceptive method. If combined with atazanavir without ritonavir, keep ethinyl estradiol dose at the lowest effective level.
What other medicines interact with Ethinyl estradiol-levonorgestrel?
MediHelp also lists interactions of Ethinyl estradiol-levonorgestrel with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-levonorgestrel page.
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