Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil
Severity: Contraindicated
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Sildenafil: contraindicated 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
The cobicistat component strongly inhibits CYP3A and raises sildenafil exposure considerably. This increases the likelihood of hypotension, syncope, visual disturbances and priapism.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Sildenafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Cobicistat inhibits CYP3A4, decreasing the metabolism of sildenafil.
What to do
Do not use sildenafil for pulmonary arterial hypertension with this regimen. For erectile dysfunction, cap the dose at 25 mg per 48 hours and monitor for adverse effects.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
- Isosorbide mononitrate + Sildenafil Contraindicated
Frequently asked questions
Can I take Elvitegravir / cobicistat / emtricitabine / tenofovir df with Sildenafil?
MediHelp rates the interaction as contraindicated. Elvitegravir / cobicistat / emtricitabine / tenofovir df and Sildenafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. The cobicistat component strongly inhibits CYP3A and raises sildenafil exposure considerably. This increases the likelihood of hypotension, syncope, visual disturbances and priapism.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df and Sildenafil?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not use sildenafil for pulmonary arterial hypertension with this regimen. For erectile dysfunction, cap the dose at 25 mg per 48 hours and monitor for adverse effects.
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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