Drug interactions
Nafcillin + Norethisterone
Severity: Moderate
Nafcillin and Norethisterone: 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 induces CYP3A4 and may lower norethisterone concentrations, which can reduce contraceptive effectiveness and cause breakthrough bleeding.
What this interaction means in plain words
Nafcillin and Norethisterone 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
Nafcillin induces CYP3A4, increasing norethisterone clearance.
What to do
Use a non-hormonal contraceptive method during nafcillin therapy and for a short period 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 Norethisterone
- Acitretin + Norethisterone Contraindicated
- Amobarbital + Norethisterone Major
- Apalutamide + Norethisterone Major
- Belzutifan + Norethisterone Major
- Bosentan + Norethisterone Major
- Brigatinib + Norethisterone Major
Frequently asked questions
Can I take Nafcillin with Norethisterone?
MediHelp rates the interaction as moderate. Nafcillin and Norethisterone 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 induces CYP3A4 and may lower norethisterone concentrations, which can reduce contraceptive effectiveness and cause breakthrough bleeding.
How serious is the interaction between Nafcillin and Norethisterone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-hormonal contraceptive method during nafcillin therapy and for a short period after stopping.
What other medicines interact with Norethisterone?
MediHelp also lists interactions of Norethisterone with, for example, Acitretin, Amobarbital, Apalutamide. The full list is on the Norethisterone page.
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