Acetaminophen and Sulfinpyrazone: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sulfinpyrazone
No brand names on recordAcetaminophen
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased hepatotoxicity in acetaminophen overdose
Interaction Deep Dive
Pretreatment with sulfinpyrazone (800 mg daily) has resulted in an increased metabolism of acetaminophen by about 20%. Patients may be at greater risk of acetaminophen toxicity when taking sulfinpyrazone. In addition, the duration of analgesia may be shorter1.
Why it happens (mechanism)
Increased hepatic metabolism of acetaminophen
Common questions
Can I take Acetaminophen and Sulfinpyrazone together?
Increased hepatotoxicity in acetaminophen overdose Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen and Sulfinpyrazone interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Acetaminophen or Sulfinpyrazone need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Miners JO, Attwood J, & Birkett DJ: Determinants of acetaminophen metabolism: effect of inducers and inhibitors of drug metabolism on acetaminophen's metabolic pathways. Clin Pharmacol Ther 1984; 35:480-486. DOI
Keep reading about Sulfinpyrazone
Keep reading about Acetaminophen
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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