What the FDA labels say about taking them together
Darunavir and perphenazine
Darunavir's FDA label of August 29, 2025 names perphenazine in its drug interactions section; the perphenazine label PlainMeds reads does not name darunavir. The darunavir label: “A decrease in the dose of antipsychotics that are metabolized by CYP3A or CYP2D6 may be needed when co-administered with PREZISTA/ritonavir.”
Check it at the source: the darunavir FDA label on DailyMed (effective August 29, 2025, Janssen Products LP); the perphenazine FDA label on DailyMed (effective December 12, 2024, Rising Pharma Holdings, Inc.).
What does the darunavir label say about perphenazine?
Darunavir label, drug interactionsConcomitant Drug Class Drug Name Examples: e.g. perphenazine, risperidone, thioridazine; Effect on Concentration of Darunavir Or Concomitant Drug: ↑ antipsychotics; Clinical Comment: A decrease in the dose of antipsychotics that are metabolized by CYP3A or CYP2D6 may be needed when co-administered with PREZISTA/ritonavir.
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 perphenazine label say about darunavir?
Perphenazine's label (effective December 12, 2024) does 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 (PERPHENAZINE), Rising Pharma Holdings, Inc., effective December 12, 2024 (SPL set 0ebf4c11-1810-42f6-a8e3-071616e33d5d), 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 | Perphenazine | |
|---|---|---|
| Labeled for | HIV | Schizophrenia, Nausea and vomiting |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.16 per tablet 600 mg tablet | $0.161 per tablet 4 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