Drug interactions
Nafcillin + Simvastatin
Severity: Minor
Nafcillin and Simvastatin: minor 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 can induce CYP3A4 and has been shown to reduce concentrations of other CYP3A4 substrates. Simvastatin levels may fall and its lipid-lowering effect may weaken during a course of treatment. Because this is an efficacy issue and treatment is typically short, it does not justify a contraindication.
What this interaction means in plain words
Nafcillin and Simvastatin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Nafcillin induces CYP3A4, accelerating the metabolism of simvastatin.
What to do
No action is usually needed for a short course. Recheck lipids if nafcillin is used for prolonged therapy.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Simvastatin
- Atazanavir + Simvastatin Contraindicated
- Clarithromycin + Simvastatin Contraindicated
- Cobicistat + Simvastatin Contraindicated
- Cyclosporine + Simvastatin Contraindicated
- Cyclosporin + Simvastatin Contraindicated
- Danazol + Simvastatin Contraindicated
Frequently asked questions
Can I take Nafcillin with Simvastatin?
MediHelp rates the interaction as minor. Nafcillin and Simvastatin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Nafcillin can induce CYP3A4 and has been shown to reduce concentrations of other CYP3A4 substrates. Simvastatin levels may fall and its lipid-lowering effect may weaken during a course of treatment. Because this is an efficacy issue and treatment is typically short, it does not justify a contraindication.
How serious is the interaction between Nafcillin and Simvastatin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No action is usually needed for a short course. Recheck lipids if nafcillin is used for prolonged therapy.
What other medicines interact with Simvastatin?
MediHelp also lists interactions of Simvastatin with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Simvastatin page.
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