What the FDA labels say about taking them together
Nateglinide and phenytoin
Nateglinide's FDA label of February 24, 2025 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name nateglinide. The nateglinide label: “Drugs and Herbals That May Reduce the Blood-Glucose-Lowering Effect of Nateglinide and Increase Susceptibility to Hyperglycemia Drugs: Thiazides, corticosteroids, thyroid products, sympathomimetics, somatropin …”
Check it at the source: the nateglinide FDA label on DailyMed (effective February 24, 2025, Strides Pharma Science Limited); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the nateglinide label say about phenytoin?
Nateglinide label, drug interactionsDrugs and Herbals That May Reduce the Blood-Glucose-Lowering Effect of Nateglinide and Increase Susceptibility to Hyperglycemia Drugs: Thiazides, corticosteroids, thyroid products, sympathomimetics, somatropin, somatostatin analogues (e.g., lanreotide, octreotide), and CYP inducers (e.g., rifampin, phenytoin and St John's Wort). Intervention: Dose increases and increased frequency of glucose monitoring may be required when nateglinide is coadministered with these drugs.
Source: FDA drug label (Nateglinide), Strides Pharma Science Limited, effective February 24, 2025 (SPL set 0ccf9b07-3c21-482d-abeb-a06ceb482c7b), via openFDA; the full label on DailyMed
What does the phenytoin label say about nateglinide?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name nateglinide 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
| Nateglinide | Phenytoin | |
|---|---|---|
| Labeled for | Type 2 diabetes | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.179 per tablet 60 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