Sulfinpyrazone and Aspirin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sulfinpyrazone
No brand names on recordAspirin
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
A reduction in uricosuric effect and an increased risk of bleeding
Interaction Deep Dive
Concomitant use of aspirin and sulfinpyrazone may antagonize the uricosuric action of sulfinpyrazone12. Aspirin and sulfinpyrazone mutually inhibit each other's uricosuric effects. In addition, the use of sulfinpyrazone has been demonstrated to decrease the excretion of aspirin 45678. Doses of aspirin 2 grams daily or more are required to cause this effect. Avoid concurrent use if a uricosuric effect is desired. Additionally, coadministration of aspirin, an antiplatelet agent, and sulfinpyrazone, also an antiplatelet agent, may increase the risk of bleeding 1.
Why it happens (mechanism)
Altered uric acid excretion; additive inhibition of platelet aggregation
Literature reports
1 report — tap to read
a) A study reported the effects of concurrent aspirin ingestion on sulfinpyrazone clearance in healthy volunteers. Six subjects received sulfinpyrazone 200 mg four times daily combined with aspirin 325 four times daily for one week, and the sulfinpyrazone clearance after a final 400 mg dose was compared to the clearance observed when these same subjects received sulfinpyrazone alone. Concurrent aspirin ingestion caused sulfinpyrazone clearance to increase in five of the six subjects from 50% to 200%. Clearance decreased by 10% in the sixth subject. Sulfinpyrazone elimination half-life was not changed by aspirin in single-dose studies, leading to the conclusion that sulfinpyrazone clearance was increased secondary to an increase in its volume of distribution caused by aspirin-induced displacement of sulfinpyrazone from plasma proteins 3.
Common questions
Can I take Sulfinpyrazone and Aspirin together?
A reduction in uricosuric effect and an increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sulfinpyrazone and Aspirin interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
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 Sulfinpyrazone or Aspirin 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 (8)
- Product Information: AGGRENOX(R) oral extended release capsules, aspirin dipyridamole oral extended release capsules. Boehringer Ingelheim Pharmaceuticals, Inc. (per FDA), Ridgefield, CT, 2012. DailyMed
- Product Information: PERCODAN(R) oral tablets, oxycodone aspirin oral tablets. Endo Pharmaceuticals Inc. (per FDA), Malvern, PA, 2021.
- Buchanan MR, Endrenyi L, Giles AR, et al: The effect of aspirin on the pharmacokinetics of sulfinpyrazone in man. Thromb Res Suppl 1983; 4:145-152. PubMed
- Yu TF, Dayton PG, & Gutman AB: Mutual suppression of the uricosuric effects of sulfinpyrazone and salicylate: a study in interaction between drugs. J Clin Invest 1963; 42:1330.
- Seegmiller JE & Grayzel AI: Use of newer uricosuric agents in the management of gout. JAMA 1960; 173:1076.
- AnonAnon: Evaluation of Drug Interactions, 2nd. American Pharmaceutical Association, Washington, DC, 1976.
- Avery GS: Check-list to potential clinically important interactions. Drugs 1973; 5:187-211. PubMed
- Cohen SN & Armstrong MFCohen SN & Armstrong MF: Drug Interactions, Williams & Wilkins, Baltimore, MD, 1974.
Keep reading about Sulfinpyrazone
Keep reading about Aspirin
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