Drug interactions
Nafcillin + Tamoxifen
Severity: Moderate
Nafcillin and Tamoxifen: 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 tamoxifen and active metabolite concentrations. The effect is usually limited by the short duration of antibiotic therapy.
What this interaction means in plain words
Nafcillin and Tamoxifen 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 tamoxifen clearance.
What to do
Use an alternative antibiotic if feasible; for short courses no adjustment 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?
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Other interactions of Tamoxifen
- Amiodarone + Tamoxifen Major
- Anastrozole + Tamoxifen Major
- Bupropion + Tamoxifen Major
- Carbamazepine + Tamoxifen Major
- Cinacalcet + Tamoxifen Major
- Dacomitinib + Tamoxifen Major
Frequently asked questions
Can I take Nafcillin with Tamoxifen?
MediHelp rates the interaction as moderate. Nafcillin and Tamoxifen 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 tamoxifen and active metabolite concentrations. The effect is usually limited by the short duration of antibiotic therapy.
How serious is the interaction between Nafcillin and Tamoxifen?
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 an alternative antibiotic if feasible; for short courses no adjustment is needed.
What other medicines interact with Tamoxifen?
MediHelp also lists interactions of Tamoxifen with, for example, Amiodarone, Anastrozole, Bupropion. The full list is on the Tamoxifen page.
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