What the FDA labels say about taking them together
Maribavir and phenytoin
Maribavir's FDA label of January 27, 2026 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name maribavir. The maribavir label: “A dose adjustment of LIVTENCITY to 1,200 mg twice daily is recommended when coadministration with phenytoin.”
Check it at the source: the maribavir FDA label on DailyMed (effective January 27, 2026, Takeda Pharmaceuticals America, Inc.); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the maribavir label say about phenytoin?
Maribavir label, drug interactionsConcomitant Drug Class/Drug Name: Phenytoin; Effect on Concentration: ↓ Maribavir; Clinical Comments: A dose adjustment of LIVTENCITY to 1,200 mg twice daily is recommended when coadministration with phenytoin.
Maribavir label, warnings and precautionsThus, coadministration of LIVTENCITY with these drugs is not recommended, except with a dose adjustment when coadministered with selected anticonvulsants (carbamazepine and phenytoin).
Source: FDA drug label (Livtencity), Takeda Pharmaceuticals America, Inc., effective January 27, 2026 (SPL set c94fc2c5-e840-4f18-b7d8-d5eacb26d3a0), via openFDA; the full label on DailyMed
What does the phenytoin label say about maribavir?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name maribavir 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
| Maribavir | Phenytoin | |
|---|---|---|
| Labeled for | n/a | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $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