What the FDA labels say about taking them together
Darunavir and tadalafil
Darunavir's FDA label of August 29, 2025 names tadalafil in its drug interactions section; the tadalafil labels PlainMeds reads (3) do not name darunavir. The darunavir label: “… adverse reactions. The following dose adjustments are recommended for use of tadalafil with PREZISTA/ritonavir: Co-administration of tadalafil in patients on PREZISTA/ritonavir: In patients receiving PREZISTA/ritonavir …”
Check it at the source: the darunavir FDA label on DailyMed (effective August 29, 2025, Janssen Products LP); the tadalafil FDA label on DailyMed (effective June 3, 2026, Eli Lilly and Company).
What does the darunavir label say about tadalafil?
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 tadalafil label say about darunavir?
Tadalafil's label (effective June 3, 2026) and its 2 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 (Cialis), Eli Lilly and Company, effective June 3, 2026 (SPL set bcd8f8ab-81a2-4891-83db-24a0b0e25895), 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 | Tadalafil | |
|---|---|---|
| Labeled for | HIV | Erectile dysfunction, Enlarged prostate (BPH), Pulmonary arterial hypertension |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.16 per tablet 600 mg tablet | $0.167 per tablet 20 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