What the FDA labels say about taking them together
Isoniazid and prednisolone
Prednisolone's FDA label (Orapred Odt) of June 3, 2025 names isoniazid in its drug interactions section; the isoniazid label PlainMeds reads does not name prednisolone. The prednisolone label: “Antitubercular drugs: Serum concentrations of isoniazid may be decreased.”
Check it at the source: the isoniazid FDA label on DailyMed (effective July 8, 2025, OMNIVIUM PHARMACEUTICALS LLC.); the prednisolone FDA label on DailyMed (effective June 25, 2026, PAI Holdings, LLC dba PAI Pharma).
What does the isoniazid label say about prednisolone?
Isoniazid's label (effective July 8, 2025) does not name prednisolone 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
What does the prednisolone label say about isoniazid?
Orapred Odt label (Advanz Pharma (US) Corp., June 3, 2025), drug interactionsAntitubercular drugs: Serum concentrations of isoniazid may be decreased.
Source: FDA drug label (Orapred Odt, NDA021959), Advanz Pharma (US) Corp., effective June 3, 2025 (SPL set 1e379543-c4cf-4e72-953b-db15b7f0c2a1), via openFDA
Source: FDA drug label (PrednisoLONE Sodium Phosphate), PAI Holdings, LLC dba PAI Pharma, effective June 25, 2026 (SPL set d1f937e7-fed5-4079-bd52-5d930b34ae9f), 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
| Isoniazid | Prednisolone | |
|---|---|---|
| Labeled for | n/a | Anemia, Leukemia, lymphoma and myeloma, Multiple sclerosis, Osteoarthritis, Asthma, Allergies, Herpes and shingles, Crohn's disease and ulcerative colitis, Eczema (atopic dermatitis), Organ transplant rejection |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $3.40 per tablet 300 mg tablet | $4.72 per mL 1% eye drop |
| 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