Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Ethinyl estradiol-norgestimate
Severity: Moderate
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ethinyl estradiol-norgestimate: 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
Cobicistat inhibits CYP3A4 and may increase exposure to norgestimate metabolites, while elvitegravir boosted by cobicistat can alter ethinyl estradiol levels. Hormone exposure changes may affect contraceptive efficacy and tolerability.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ethinyl estradiol-norgestimate 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.
Why it happens
Cobicistat inhibits CYP3A4 and may alter hormone metabolism, with variable effects on estrogen and progestin exposure.
What to do
Review the contraceptive choice and add a barrier method if reliability is uncertain. Monitor for progestogenic adverse effects, bleeding changes and contraceptive failure.
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 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
Frequently asked questions
Can I take Elvitegravir / cobicistat / emtricitabine / tenofovir df with Ethinyl estradiol-norgestimate?
MediHelp rates the interaction as moderate. Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ethinyl estradiol-norgestimate 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. Cobicistat inhibits CYP3A4 and may increase exposure to norgestimate metabolites, while elvitegravir boosted by cobicistat can alter ethinyl estradiol levels. Hormone exposure changes may affect contraceptive efficacy and tolerability.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df and Ethinyl estradiol-norgestimate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Review the contraceptive choice and add a barrier method if reliability is uncertain. Monitor for progestogenic adverse effects, bleeding changes and contraceptive failure.
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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