Drug interactions
Darunavir + Sildenafil
Severity: Major
Darunavir and Sildenafil: major interaction.
Last updated Sources: US FDA label
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
Boosted darunavir regimens strongly inhibit CYP3A4 and substantially increase sildenafil exposure. This raises the risk of hypotension, syncope, visual disturbances and priapism.
What this interaction means in plain words
Darunavir and Sildenafil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Darunavir belongs to Anti Virals; Sildenafil belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4 by darunavir and its pharmacokinetic booster reduces sildenafil clearance.
What to do
For erectile dysfunction, limit sildenafil to 25 mg no more than once every 48 hours. For pulmonary arterial hypertension, avoid sildenafil unless the label permits and monitor closely.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Darunavir
- Alfuzosin + Darunavir Contraindicated
- Avanafil + Darunavir Contraindicated
- Darunavir + Dronedarone Contraindicated
- Darunavir + Eletriptan Contraindicated
- Darunavir + Ergotamine Contraindicated
- Darunavir + Flibanserin Contraindicated
Frequently asked questions
Can I take Darunavir with Sildenafil?
MediHelp rates the interaction as major. Darunavir and Sildenafil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Boosted darunavir regimens strongly inhibit CYP3A4 and substantially increase sildenafil exposure. This raises the risk of hypotension, syncope, visual disturbances and priapism.
How serious is the interaction between Darunavir and Sildenafil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: For erectile dysfunction, limit sildenafil to 25 mg no more than once every 48 hours. For pulmonary arterial hypertension, avoid sildenafil unless the label permits and monitor closely.
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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