Drug interactions
Ethinyl estradiol-drospirenone + Nafcillin
Severity: Moderate
Ethinyl estradiol-drospirenone 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 an enzyme inducer that can lower circulating ethinyl estradiol and drospirenone concentrations. This may reduce contraceptive efficacy and cause breakthrough bleeding or unintended pregnancy, especially with prolonged courses.
What this interaction means in plain words
Ethinyl estradiol-drospirenone 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 hepatic and intestinal CYP3A4 by nafcillin increases the metabolism of ethinyl estradiol and drospirenone.
What to do
Advise an additional non-hormonal barrier method during nafcillin therapy and for about 7 days after stopping. Consider an alternative contraceptive method if long-term treatment is needed.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Ethinyl estradiol-drospirenone and Nafcillin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Ethinyl estradiol-drospirenone
- Ethinyl estradiol-drospirenone + Fezolinetant Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-drospirenone + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-drospirenone Major
- Amobarbital + Ethinyl estradiol-drospirenone Major
Frequently asked questions
Can I take Ethinyl estradiol-drospirenone with Nafcillin?
MediHelp rates the interaction as moderate. Ethinyl estradiol-drospirenone 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 an enzyme inducer that can lower circulating ethinyl estradiol and drospirenone concentrations. This may reduce contraceptive efficacy and cause breakthrough bleeding or unintended pregnancy, especially with prolonged courses.
How serious is the interaction between Ethinyl estradiol-drospirenone 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 non-hormonal barrier method during nafcillin therapy and for about 7 days after stopping. Consider an alternative contraceptive method if long-term treatment is needed.
What other medicines interact with Ethinyl estradiol-drospirenone?
MediHelp also lists interactions of Ethinyl estradiol-drospirenone with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir, Ombitasvir / paritaprevir / ritonavir and dasabuvir. The full list is on the Ethinyl estradiol-drospirenone page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
