What the FDA labels say about taking them together
Fluconazole and phenytoin
Fluconazole's FDA label (Fluconazole) of April 2, 2026 names phenytoin in its drug interactions section, and phenytoin's label names fluconazole too. The fluconazole label: “Drug Interaction Studies.) Phenytoin Fluconazole increases the plasma concentrations of phenytoin.”
Check it at the source: the fluconazole FDA label on DailyMed (effective April 7, 2026, Zydus Pharmaceuticals (USA) Inc.); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the fluconazole label say about phenytoin?
Fluconazole label (Mylan Pharmaceuticals Inc., April 2, 2026), drug interactionsDrug Interaction Studies .) Phenytoin Fluconazole increases the plasma concentrations of phenytoin.
Source: FDA drug label (Fluconazole, NDA020090), Mylan Pharmaceuticals Inc., effective April 2, 2026 (SPL set 737e0fac-a2d2-4053-a0d7-edbfb6248f69), via openFDA
Source: FDA drug label (fluconazole), Zydus Pharmaceuticals (USA) Inc., effective April 7, 2026 (SPL set d1364455-1537-46d4-b093-38cca3be778f), via openFDA; the full label on DailyMed
What does the phenytoin label say about fluconazole?
Phenytoin label, drug interactionsInteracting Agent: Azoles; Examples: Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole
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
| Fluconazole | Phenytoin | |
|---|---|---|
| Labeled for | Fungal infections, Urinary tract infections | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.380 per tablet 200 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