What the FDA labels say about taking them together
Estazolam and phenytoin
Estazolam's FDA label of November 11, 2022 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name estazolam. The estazolam label: “While no in vivo drug-drug interaction studies were conducted between estazolam and inducers of CYP3A, compounds that are potent CYP3A inducers would be expected to decrease estazolam concentrations.”
Check it at the source: the estazolam FDA label on DailyMed (effective November 11, 2022, Novitium Pharma LLC); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the estazolam label say about phenytoin?
Estazolam label, drug interactionsWhile no in vivo drug-drug interaction studies were conducted between estazolam and inducers of CYP3A, compounds that are potent CYP3A inducers (such as carbamazepine, phenytoin, rifampin, and barbiturates) would be expected to decrease estazolam concentrations.
Source: FDA drug label (Estazolam), Novitium Pharma LLC, effective November 11, 2022 (SPL set e1c77eb1-9cba-4e89-a03f-9fb797add4f0), via openFDA; the full label on DailyMed
What does the phenytoin label say about estazolam?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name estazolam 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
| Estazolam | Phenytoin | |
|---|---|---|
| Labeled for | Insomnia | Seizures and epilepsy |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.839 per tablet 2 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