Sildenafil and Darunavir Interaction

Drug interaction information between Sildenafil and Darunavir.

Sildenafil and Darunavir have a documented major interaction in FDA labeling.

FDA drug labeling documents a major-severity interaction between Sildenafil and Darunavir. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Sildenafil

PDE5 Inhibitor

Drug B

Darunavir

HIV Protease Inhibitor

How They Interact

Darunavir increases the amount of sildenafil in your system, which can cause very low blood pressure or fainting.

FDA Label Information

avanafil, sildenafil, tadalafil, vardenafil ↑ PDE-5 inhibitors (only the use of sildenafil at doses used for treatment of erectile dysfunction has been studied with darunavir/ritonavir) Co-administration with darunavir/ritonavir may result in an increase in PDE-5 inhibitor-associated adverse events, including hypotension, syncope, visual disturbances and priapism. Use of PDE-5 inhibitors for pulmonary arterial hypertension (PAH): Co-administration with sildenafil used for PAH is contraindicated due to potential for sildenafil associated adverse reactions (which include visual disturbances,...

Frequently Asked Questions

What SPL severity band is on file for Sildenafil + Darunavir?

Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Darunavir has 101 labeled pairs on file vs Sildenafil's 10. In the major band specifically: Sildenafil has 6 (also Ketoconazole, Erythromycin, Itraconazole, Hydralazine); Darunavir has 15 (also Lovastatin, Lurasidone, Pimozide, Midazolam).

What mechanism field is on file for Sildenafil and Darunavir?

Darunavir increases the amount of sildenafil in your system, which can cause very low blood pressure or fainting.

Darunavir carries more major-labeled pairs than Sildenafil

SPL source-record counts only. This page's band is major · classes on file: Sildenafil (PDE5 Inhibitor); Darunavir (HIV Protease Inhibitor).

Darunavir has 15 major-labeled pairs vs Sildenafil's 6.

Sildenafil

6 major · 1 moderate · 3 minor · 10 total

Darunavir

15 major · 16 moderate · 70 minor · 101 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.