What the FDA labels say about taking them together
Darunavir and sildenafil
Darunavir's FDA label of August 29, 2025 names sildenafil in its contraindications section; the sildenafil labels PlainMeds reads (4) do not name darunavir. The darunavir label: “… inhibitors for pulmonary arterial hypertension (PAH): Co-administration with sildenafil used for PAH is contraindicated due to potential for sildenafil associated adverse reactions. …”
Check it at the source: the darunavir FDA label on DailyMed (effective August 29, 2025, Janssen Products LP); the sildenafil FDA label on DailyMed (effective November 17, 2023, Viatris Specialty LLC).
What does the darunavir label say about sildenafil?
Darunavir label, contraindicationsSt. John's wort ( Hypericum perforatum ) Hepatitis C direct acting antiviral: elbasvir/grazoprevir Lipid modifying agents: lomitapide, lovastatin, simvastatin Opioid Antagonist: naloxegol PDE-5 inhibitor: sildenafil when used for treatment of pulmonary arterial hypertension Sedatives/hypnotics: orally administered midazolam, triazolam Co-administration of PREZISTA/ritonavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events (narrow therapeutic index).
Darunavir label, drug interactionsConcomitant Drug Class Drug Name Examples: PDE-5 inhibitors: e.g. avanafil, sildenafil, tadalafil, vardenafil; Effect on Concentration of Darunavir Or Concomitant Drug: ↑ PDE-5 inhibitors (only the use of sildenafil at doses used for treatment of erectile dysfunction has been studied with PREZISTA/ritonavir); Clinical Comment: Co-administration with PREZISTA/ritonavir may result in an increase in PDE-5 inhibitor-associated adverse events, including hypotension, syncope, visual disturbances and priapism. …
Source: FDA drug label (PREZISTA), Janssen Products LP, effective August 29, 2025 (SPL set 814301f9-c990-46a5-b481-2879a521a16f), via openFDA; the full label on DailyMed
What does the sildenafil label say about darunavir?
Sildenafil's label (effective November 17, 2023) and its 3 other brand-application labels do not name darunavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Viagra), Viatris Specialty LLC, effective November 17, 2023 (SPL set d905dc8d-917f-4ea3-a4ee-a1ecf6967d4e), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Darunavir | Sildenafil | |
|---|---|---|
| Labeled for | HIV | Erectile dysfunction, Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.16 per tablet 600 mg tablet | $0.132 per tablet 100 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once