What the FDA labels say about taking them together
Acetaminophen and diflunisal
Diflunisal's FDA label of August 4, 2026 names acetaminophen in its drug interactions section; the acetaminophen labels PlainMeds reads (4) do not name diflunisal. The diflunisal label: “Acetaminophen In normal volunteers, concomitant administration of diflunisal and acetaminophen resulted in an approximate 50% increase in plasma levels of acetaminophen.”
Check it at the source: the acetaminophen FDA label on DailyMed (effective November 13, 2024, Kenvue Brands LLC); the diflunisal FDA label on DailyMed (effective August 4, 2026, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.).
What does the acetaminophen label say about diflunisal?
Acetaminophen's label (effective November 13, 2024) and its 3 other brand-application labels do not name diflunisal in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Tylenol 8 HR Arthritis Pain), Kenvue Brands LLC, effective November 13, 2024 (SPL set 3af22fc8-e4e0-4863-8696-6bc1257047cb), via openFDA; the full label on DailyMed
What does the diflunisal label say about acetaminophen?
Diflunisal label, drug interactionsAcetaminophen In normal volunteers, concomitant administration of diflunisal and acetaminophen resulted in an approximate 50% increase in plasma levels of acetaminophen.
Source: FDA drug label (diflunisal), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective August 4, 2026 (SPL set 666f89b4-fd81-420a-a390-eb1cd4014f61), 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
| Acetaminophen | Diflunisal | |
|---|---|---|
| Labeled for | Fever, Cough and cold, Pain | Pain, Osteoarthritis, Rheumatoid arthritis |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0339 per unit 500 mg caplet | $1.06 per tablet 500 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