What the FDA labels say about taking them together
Brivaracetam and phenytoin
Brivaracetam's FDA label of August 20, 2026 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name brivaracetam. The brivaracetam label: “Because phenytoin concentrations can increase, phenytoin levels should be monitored in patients on concomitant BRIVIACT.”
Check it at the source: the brivaracetam FDA label on DailyMed (effective August 20, 2026, UCB, Inc.); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the brivaracetam label say about phenytoin?
Brivaracetam label, drug interactionsBecause phenytoin concentrations can increase, phenytoin levels should be monitored in patients on concomitant BRIVIACT.
Source: FDA drug label (Briviact), NDA205836 (Ucb Inc), as published by UCB, Inc., effective August 20, 2026 (SPL set 3cf2f439-0e97-443e-8e33-25ecef616f6c), via openFDA; the full label on DailyMed
What does the phenytoin label say about brivaracetam?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name brivaracetam 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
| Brivaracetam | Phenytoin | |
|---|---|---|
| Labeled for | Seizures and epilepsy | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.259 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