Drug interactions
Atazanavir + Sildenafil
Severity: Contraindicated
Atazanavir 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
Atazanavir inhibits CYP3A4 and can markedly raise sildenafil exposure, increasing the risk of hypotension, syncope, visual disturbances and priapism. With the higher, chronic dosing used for pulmonary arterial hypertension the risk is unacceptable.
What this interaction means in plain words
Atazanavir 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.
Atazanavir belongs to Anti Virals; Sildenafil belongs to Genitourinary.
Why it happens
Atazanavir inhibits CYP3A4-mediated first-pass and hepatic metabolism of sildenafil, raising its plasma concentrations.
What to do
Do not combine atazanavir with sildenafil for pulmonary arterial hypertension. For erectile dysfunction, use a reduced sildenafil dose (for example 25 mg no more often than every 48 hours) and counsel on hypotension and priapism.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Atazanavir and Sildenafil, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
- Isosorbide mononitrate + Sildenafil Contraindicated
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Sildenafil?
MediHelp rates the interaction as contraindicated. Atazanavir 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. Atazanavir inhibits CYP3A4 and can markedly raise sildenafil exposure, increasing the risk of hypotension, syncope, visual disturbances and priapism. With the higher, chronic dosing used for pulmonary arterial hypertension the risk is unacceptable.
How serious is the interaction between Atazanavir 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 combine atazanavir with sildenafil for pulmonary arterial hypertension. For erectile dysfunction, use a reduced sildenafil dose (for example 25 mg no more often than every 48 hours) and counsel on hypotension and priapism.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Cobicistat, Elvitegravir / cobicistat / emtricitabine / tenofovir df. The full list is on the Sildenafil page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
