What the FDA labels say about taking them together
Glimepiride and isoniazid
Glimepiride's FDA label of May 12, 2025 names isoniazid in its drug interactions section; the isoniazid label PlainMeds reads does not name glimepiride. The glimepiride label: “… estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, and isoniazid.”
Check it at the source: the glimepiride FDA label on DailyMed (effective May 12, 2025, Micro Labs Limited); the isoniazid FDA label on DailyMed (effective July 8, 2025, OMNIVIUM PHARMACEUTICALS LLC.).
What does the glimepiride label say about isoniazid?
Glimepiride label, drug interactionsThe following are examples of medications that may reduce the glucose-lowering effect of sulfonylureas including glimepiride, leading to worsening glycemic control: danazol, glucagon, somatropin, protease inhibitors, atypical antipsychotic medications (e.g., olanzapine and clozapine), barbiturates, diazoxide, laxatives, rifampin, thiazides and other diuretics, corticosteroids, phenothiazines, thyroid hormones, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics (e.g., epinephrine, albuterol, terbutaline), and isoniazid.
Source: FDA drug label (Glimepiride), Micro Labs Limited, effective May 12, 2025 (SPL set 60e9397e-83b9-489e-9683-6f87e458bbaa), via openFDA; the full label on DailyMed
What does the isoniazid label say about glimepiride?
Isoniazid's label (effective July 8, 2025) does not name glimepiride in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (isoniazid), OMNIVIUM PHARMACEUTICALS LLC., effective July 8, 2025 (SPL set 35400f1d-fd25-4bfa-a382-ac390e21bf2e), 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
| Glimepiride | Isoniazid | |
|---|---|---|
| Labeled for | Type 2 diabetes | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0507 per tablet 4 mg tablet | $3.40 per tablet 300 mg tablet |
| 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