Drug interactions
Nafcillin + Sildenafil
Severity: Minor
Nafcillin and Sildenafil: 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 may induce CYP3A4 and reduce sildenafil concentrations. The clinical effect is likely modest and mostly relevant during prolonged therapy.
What this interaction means in plain words
Nafcillin and Sildenafil 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, modestly increasing sildenafil metabolism.
What to do
Monitor for reduced sildenafil efficacy during prolonged nafcillin courses and adjust therapy if the response is lost.
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 Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
Frequently asked questions
Can I take Nafcillin with Sildenafil?
MediHelp rates the interaction as minor. Nafcillin and Sildenafil 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 may induce CYP3A4 and reduce sildenafil concentrations. The clinical effect is likely modest and mostly relevant during prolonged therapy.
How serious is the interaction between Nafcillin and Sildenafil?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for reduced sildenafil efficacy during prolonged nafcillin courses and adjust therapy if the response is lost.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Atazanavir, Cobicistat. The full list is on the Sildenafil page.
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