What the FDA labels say about taking them together
Glipizide and phenytoin
Glipizide's FDA label of January 8, 2026 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name glipizide. The glipizide label: “… protease inhibitors, somatropin, sympathomimetic agents, thyroid hormones, phenytoin, nicotinic acid, and calcium channel blocking drugs.”
Check it at the source: the glipizide FDA label on DailyMed (effective January 8, 2026, Aurobindo Pharma Limited); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the glipizide label say about phenytoin?
Glipizide label, drug interactionsThe following are examples of medication that may reduce the glucose-lowering effect of glipizide extended-release tablets, leading to worsening glycemic control: atypical antipsychotics (e.g., olanzapine and clozapine), corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives, phenothiazines, progestogens (e.g., in oral contraceptives), protease inhibitors, somatropin, sympathomimetic agents (e.g., albuterol, epinephrine, terbutaline), thyroid hormones, phenytoin, nicotinic acid, and calcium channel blocking drugs.
Source: FDA drug label (Glucotrol Xl, NDA020329), Roerig, effective July 21, 2026 (SPL set eed99b60-d043-4249-9b2a-f05e46fb588d), via openFDA
Source: FDA drug label (Glipizide), Aurobindo Pharma Limited, effective January 8, 2026 (SPL set 84794a52-b717-488c-8533-6425c83d405f), via openFDA; the full label on DailyMed
What does the phenytoin label say about glipizide?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name glipizide 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
| Glipizide | Phenytoin | |
|---|---|---|
| Labeled for | Type 2 diabetes | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0339 per tablet 5 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