What the FDA labels say about taking them together
Cenobamate and phenytoin
Cenobamate's FDA label of August 25, 2025 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name cenobamate. The cenobamate label: “DRUG INTERACTIONS Phenytoin: Gradually decrease phenytoin dosage by up to 50%. Phenobarbital and Clobazam:”
Check it at the source: the cenobamate FDA label on DailyMed (effective August 25, 2025, SK Life Science, Inc.); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the cenobamate label say about phenytoin?
Cenobamate label, drug interactionsDRUG INTERACTIONS Phenytoin: Gradually decrease phenytoin dosage by up to 50%. ( 7.1 ) Phenobarbital and Clobazam:
Source: FDA drug label (Xcopri), SK Life Science, Inc., effective August 25, 2025 (SPL set 565c2126-57ae-4e29-b443-723bbe7e2072), via openFDA; the full label on DailyMed
What does the phenytoin label say about cenobamate?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name cenobamate in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenytek), Mylan Pharmaceuticals Inc., effective October 15, 2024 (SPL set 0f94c791-8b07-4b41-927e-c9f28bec5f60), 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
| Cenobamate | Phenytoin | |
|---|---|---|
| Labeled for | Seizures and epilepsy | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $39.87 per tablet 100 mg tablet | $0.145 per capsule 100 mg capsule |
| 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