Drug interactions
Rifapentine + Sildenafil
Severity: Moderate
Rifapentine and Sildenafil: 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
Rifapentine induces CYP3A4 and can reduce sildenafil exposure. This may result in a diminished therapeutic effect.
What this interaction means in plain words
Rifapentine and Sildenafil 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.
Rifapentine belongs to Anti Bacterial; Sildenafil belongs to Genitourinary.
Why it happens
Rifapentine induces CYP3A4, increasing the metabolism of sildenafil.
What to do
Monitor clinical response to sildenafil and consider dose adjustment or an alternative if efficacy is lost. Reassess when rifapentine is stopped, because induction wanes over weeks.
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 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
Other interactions of Rifapentine
- Ledipasvir-sofosbuvir + Rifapentine Contraindicated
- Lorlatinib + Rifapentine Contraindicated
- Lurasidone + Rifapentine Contraindicated
- Ranolazine + Rifapentine Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Rifapentine with Sildenafil?
MediHelp rates the interaction as moderate. Rifapentine and Sildenafil 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. Rifapentine induces CYP3A4 and can reduce sildenafil exposure. This may result in a diminished therapeutic effect.
How serious is the interaction between Rifapentine and Sildenafil?
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 sildenafil and consider dose adjustment or an alternative if efficacy is lost. Reassess when rifapentine is stopped, because induction wanes over weeks.
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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