Drug interactions
Rifabutin + Sildenafil
Severity: Moderate
Rifabutin 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
Rifabutin induces CYP3A4 and may lower sildenafil concentrations, potentially reducing efficacy. The induction effect is weaker than with rifampicin.
What this interaction means in plain words
Rifabutin 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.
Rifabutin belongs to Anti Bacterial; Sildenafil belongs to Genitourinary.
Why it happens
Induction of CYP3A4 increases sildenafil metabolism.
What to do
Monitor for reduced response to sildenafil and adjust the dose if clinically needed within labeled limits. Consider an alternative if efficacy is inadequate, especially in pulmonary arterial hypertension.
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 Rifabutin
- Cabotegravir + Rifabutin Contraindicated
- Lorlatinib + Rifabutin Contraindicated
- Rifabutin + Voriconazole Contraindicated
- Apixaban + Rifabutin Major
- Axitinib + Rifabutin Major
- Brexpiprazole + Rifabutin Major
Frequently asked questions
Can I take Rifabutin with Sildenafil?
MediHelp rates the interaction as moderate. Rifabutin 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. Rifabutin induces CYP3A4 and may lower sildenafil concentrations, potentially reducing efficacy. The induction effect is weaker than with rifampicin.
How serious is the interaction between Rifabutin 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 for reduced response to sildenafil and adjust the dose if clinically needed within labeled limits. Consider an alternative if efficacy is inadequate, especially in pulmonary arterial hypertension.
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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