Drug interactions
Ethinyl estradiol-levonorgestrel + Nafcillin
Severity: Moderate
Ethinyl estradiol-levonorgestrel and Nafcillin: 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
Nafcillin is a CYP3A4 inducer and may lower contraceptive hormone concentrations. This may reduce contraceptive reliability, although clinical reports are limited.
What this interaction means in plain words
Ethinyl estradiol-levonorgestrel and Nafcillin 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
Induction of CYP3A4 increases hepatic and intestinal metabolism of the hormones.
What to do
Advise an additional barrier method during nafcillin therapy and for about a week after stopping.
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-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
Frequently asked questions
Can I take Ethinyl estradiol-levonorgestrel with Nafcillin?
MediHelp rates the interaction as moderate. Ethinyl estradiol-levonorgestrel and Nafcillin 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. Nafcillin is a CYP3A4 inducer and may lower contraceptive hormone concentrations. This may reduce contraceptive reliability, although clinical reports are limited.
How serious is the interaction between Ethinyl estradiol-levonorgestrel and Nafcillin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise an additional barrier method during nafcillin therapy and for about a week after stopping.
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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