Drug interactions
Atazanavir + Ethinyl estradiol-norgestimate
Severity: Major
Atazanavir and Ethinyl estradiol-norgestimate: 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 can raise ethinyl estradiol and norgestimate exposure, while ritonavir-boosted regimens may lower estrogen levels. Either change can alter the efficacy and safety of the contraceptive.
What this interaction means in plain words
Atazanavir and Ethinyl estradiol-norgestimate 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-norgestimate belongs to Endocrine.
Why it happens
Atazanavir inhibits CYP3A4 and UGT1A1, and ritonavir boosting adds induction effects, so hormone exposure changes.
What to do
Use an oral contraceptive containing no more than the dose of ethinyl estradiol recommended in the atazanavir labeling, or use a non-hormonal method. With ritonavir, prefer a non-hormonal alternative.
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-norgestimate
- Ethinyl estradiol-norgestimate + Fezolinetant Contraindicated
- Ethinyl estradiol-norgestimate + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-norgestimate + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-norgestimate Major
- Amobarbital + Ethinyl estradiol-norgestimate Major
- Anastrozole + Ethinyl estradiol-norgestimate 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-norgestimate?
MediHelp rates the interaction as major. Atazanavir and Ethinyl estradiol-norgestimate 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 can raise ethinyl estradiol and norgestimate exposure, while ritonavir-boosted regimens may lower estrogen levels. Either change can alter the efficacy and safety of the contraceptive.
How serious is the interaction between Atazanavir and Ethinyl estradiol-norgestimate?
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 oral contraceptive containing no more than the dose of ethinyl estradiol recommended in the atazanavir labeling, or use a non-hormonal method. With ritonavir, prefer a non-hormonal alternative.
What other medicines interact with Ethinyl estradiol-norgestimate?
MediHelp also lists interactions of Ethinyl estradiol-norgestimate with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-norgestimate page.
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