What the FDA labels say about taking them together
Desvenlafaxine and perphenazine
Desvenlafaxine's FDA label of January 27, 2023 names perphenazine in its drug interactions section; the perphenazine label PlainMeds reads does not name desvenlafaxine. The desvenlafaxine label: “Substrates primarily metabolized by CYP2D6 should be dosed at the original level when co-administered with desvenlafaxine 100 mg or lower or when desvenlafaxine is discontinued.”
Check it at the source: the desvenlafaxine FDA label on DailyMed (effective January 27, 2023, Alembic Pharmaceuticals Limited); the perphenazine FDA label on DailyMed (effective December 12, 2024, Rising Pharma Holdings, Inc.).
What does the desvenlafaxine label say about perphenazine?
Desvenlafaxine label, drug interactionsSubstrates primarily metabolized by CYP2D6 (e.g., desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine) should be dosed at the original level when co-administered with desvenlafaxine 100 mg or lower or when desvenlafaxine is discontinued.
Pristiq Extended-Release label (Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., April 28, 2026), drug interactionsExamples; desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine
Source: FDA drug label (Pristiq Extended-Release, NDA021992), Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., effective April 28, 2026 (SPL set 0f43610c-f290-46ea-d186-4f998ed99fce), via openFDA
Source: FDA drug label (Desvenlafaxine), Alembic Pharmaceuticals Limited, effective January 27, 2023 (SPL set 9f74708c-6f6a-46cf-8c79-87a25c2bb6f8), via openFDA; the full label on DailyMed
What does the perphenazine label say about desvenlafaxine?
Perphenazine's label (effective December 12, 2024) does not name desvenlafaxine 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
| Desvenlafaxine | Perphenazine | |
|---|---|---|
| Labeled for | Depression | Schizophrenia, Nausea and vomiting |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.396 per unit 50 mg | $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