What the FDA labels say about taking them together
Insulin aspart and isoniazid
Insulin aspart's FDA label of June 21, 2023 names isoniazid in its drug interactions section; the isoniazid label PlainMeds reads does not name insulin aspart. The insulin aspart label: “Drugs That May Decrease the Blood Glucose Lowering Effect of Insulin Aspart Drugs: Atypical antipsychotics, corticosteroids, danazol, diuretics, estrogens, glucagon, isoniazid, niacin, oral contraceptives …”
Check it at the source: the insulin aspart FDA label on DailyMed (effective June 21, 2023, Novo Nordisk); the isoniazid FDA label on DailyMed (effective July 8, 2025, OMNIVIUM PHARMACEUTICALS LLC.).
What does the insulin aspart label say about isoniazid?
Insulin aspart label, drug interactionsDrugs That May Decrease the Blood Glucose Lowering Effect of FIASP Drugs: 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), and thyroid hormones. Intervention: Dose increases and increased frequency of glucose monitoring may be required when FIASP is co-administered with these drugs.
Source: FDA drug label (Insulin Aspart, BLA020986), Novo Nordisk Pharma, Inc., effective February 28, 2023 (SPL set bee5b358-c863-420b-be73-ced2e920c499), via openFDA
Source: FDA drug label (Merilog, BLA761325), Sanofi-Aventis U.S. LLC, effective October 7, 2025 (SPL set eee07a52-1102-4d48-9782-26061db175ad), via openFDA
Source: FDA drug label (Insulin Aspart Protamine And Insulin Aspart Mix 70/30, BLA021172), Novo Nordisk Pharma, Inc., effective February 28, 2023 (SPL set fc94baa4-3606-48bc-a781-9617ab6960ef), via openFDA
Source: FDA drug label (Fiasp), Novo Nordisk, effective June 21, 2023 (SPL set 834e7efc-393f-4c55-9125-628562a8a5cf), via openFDA; the full label on DailyMed
What does the isoniazid label say about insulin aspart?
Isoniazid's label (effective July 8, 2025) does not name insulin aspart 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
| Insulin aspart | Isoniazid | |
|---|---|---|
| Labeled for | Type 2 diabetes, Type 1 diabetes | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $6.95 per mL 100 unit/mL vial | $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