What the FDA labels say about taking them together
Acetaminophen and warfarin
Acetaminophen's FDA label of November 13, 2024 names warfarin in its drug interactions (prescription label) section; the warfarin label PlainMeds reads does not name acetaminophen. The acetaminophen label: “… normalized ratio (INR) in some patients who have been stabilized on sodium warfarin as an anticoagulant.”
Check it at the source: the acetaminophen FDA label on DailyMed (effective November 13, 2024, Kenvue Brands LLC); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the acetaminophen label say about warfarin?
Acetaminophen label, drug interactions (prescription label)DRUG INTERACTIONS Substances that induce or regulate hepatic cytochrome enzyme CYP2E1 may alter the metabolism of acetaminophen and increase its hepatotoxic potential. ( 7.1 ) Chronic oral acetaminophen use at a dose of 4,000 mg/day has been shown to cause an increase in international normalized ratio (INR) in some patients who have been stabilized on sodium warfarin as an anticoagulant.
Acetaminophen label, warningsIf you are not sure whether a drug contains acetaminophen, ask a doctor or pharmacist. if you are allergic to acetaminophen or any of the inactive ingredients in this product Ask a doctor before use if you have liver disease Ask a doctor or pharmacist before use if you are taking the blood thinning drug warfarin Stop use and ask a doctor if pain gets worse or lasts more than 10 days fever gets worse or lasts more than 3 days new symptoms occur redness or swelling is present These could be signs of a serious condition.
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 warfarin label say about acetaminophen?
Warfarin's label (effective May 29, 2026) does not name acetaminophen in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Warfarin Sodium), Amneal Pharmaceuticals LLC, effective May 29, 2026 (SPL set 558b7a0d-5490-4c1b-802e-3ab3f1efe760), 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 | Warfarin | |
|---|---|---|
| Labeled for | Fever, Cough and cold, Pain | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0339 per unit 500 mg caplet | $0.093 per tablet 2 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