Drug interactions
Nafcillin + Tadalafil
Severity: Moderate
Nafcillin and Tadalafil: 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 can induce CYP3A4 and may lower tadalafil exposure. Reduced tadalafil concentrations may result in a weaker erectile response or less benefit in other indications.
What this interaction means in plain words
Nafcillin and Tadalafil 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 the hepatic and intestinal metabolism of tadalafil.
What to do
Monitor clinical response to tadalafil and consider a dose adjustment if efficacy is lost. For pulmonary hypertension, monitor for worsening symptoms during and after nafcillin therapy.
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 Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
Frequently asked questions
Can I take Nafcillin with Tadalafil?
MediHelp rates the interaction as moderate. Nafcillin and Tadalafil 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 can induce CYP3A4 and may lower tadalafil exposure. Reduced tadalafil concentrations may result in a weaker erectile response or less benefit in other indications.
How serious is the interaction between Nafcillin and Tadalafil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clinical response to tadalafil and consider a dose adjustment if efficacy is lost. For pulmonary hypertension, monitor for worsening symptoms during and after nafcillin therapy.
What other medicines interact with Tadalafil?
MediHelp also lists interactions of Tadalafil with, for example, Amyl nitrite, Isosorbide dinitrate, Isosorbide mononitrate. The full list is on the Tadalafil page.
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