What the FDA labels say about taking them together
Fluoxetine and phenytoin
Fluoxetine's FDA label of January 8, 2026 names phenytoin in its drug interactions section, and phenytoin's label names fluoxetine too. The fluoxetine label: “Potential for elevation of haloperidol and clozapine levels Anticonvulsants: Potential for elevated phenytoin and carbamazepine levels and clinical anticonvulsant toxicity Serotonergic Drugs: Drugs that Interfere with …”
Check it at the source: the fluoxetine FDA label on DailyMed (effective January 8, 2026, Dista Products Company); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the fluoxetine label say about phenytoin?
Fluoxetine label, drug interactionsPotential for elevation of haloperidol and clozapine levels ( 7.7 ) Anticonvulsants: Potential for elevated phenytoin and carbamazepine levels and clinical anticonvulsant toxicity ( 7.7 ) Serotonergic Drugs: ( 2.9 , 2.10 , 4.1 , 5.2 ) Drugs that Interfere with Hemostasis (e.g. NSAIDs, Aspirin, Warfarin):
Source: FDA drug label (Prozac), NDA018936 (Eli Lilly And Co), as published by Dista Products Company, effective January 8, 2026 (SPL set c88f33ed-6dfb-4c5e-bc01-d8e36dd97299), via openFDA; the full label on DailyMed
What does the phenytoin label say about fluoxetine?
Phenytoin label, drug interactionsInteracting Agent: Antidepressants; Examples: Fluoxetine, fluvoxamine, sertraline
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
| Fluoxetine | Phenytoin | |
|---|---|---|
| Labeled for | Depression, Anxiety, Bipolar disorder | Seizures and epilepsy |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0519 per capsule 40 mg capsule | $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