Aspirin and Ticlopidine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Aspirin
Ticlopidine
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
An increased risk of bleeding
Interaction Deep Dive
Aspirin, an antiplatelet agent1, and ticlopidine, a platelet aggregation inhibitor, may increase the risk of bleeding when coadministered. Therefore concomitant use is not recommended as ticlopidine may potentiate the effects of aspirin 2. Although in one study, with the concomitant administration of ticlopidine (250 mg to 750 mg daily) and aspirin (1500 mg daily), ticlopidine enhanced the inhibition of collagen-induced platelet aggregation by aspirin. In contrast, aspirin had no effect on the inhibition of adenosine diphosphate-induced platelet aggregation by ticlopidine 6. Monitoring of bleeding may be warranted if coadministration is required.
Why it happens (mechanism)
Additive inhibition of platelet aggregation
Literature reports
3 reports — tap to read
a) The Intracoronary Stenting and Antithrombotic Regimen (ISAR) trial established the efficacy of combined treatment with aspirin and ticlopidine, which is now the mainstay of antithrombotic prophylactics after coronary stent placement. Multiple large studies have showed that neutropenia is rare in the first four weeks of therapy. However, neutropenia peaked at two and three months of combined therapy with ticlopidine and aspirin. The recommendation is to not withhold ticlopidine therapy after stenting. However, it is recommended to monitor regular blood counts 3.
b) One group of researchers reports that there may be a higher incidence of neutropenia than reported in patients on ticlopidine plus aspirin. It is recommended to regularly monitor blood counts even during short term therapy with ticlopidine. Because ticlopidine has such a long half-life, monitoring should continue one week after discontinuation of therapy 4.
c) Four studies demonstrated a low subacute thrombosis rate with antiplatelet therapy without implementation of anticoagulant therapy. However, in three of these trials, conflicting results were reported regarding the relative efficacy of various antiplatelet therapies. Limitations of these studies included non-randomization and poorly-designed studies. The American College of Chest Physicians (ACCP) and the American College of Cardiology (ACC) recommend the use of ticlopidine and aspirin only in low risk patients 5.
Common questions
Can I take Aspirin and Ticlopidine together?
An increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Aspirin and Ticlopidine interaction?
It is rated major. Potentially serious — often needs a change or close 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 "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Aspirin or Ticlopidine 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 a safer alternative to one of these medications for me?
References (6)
- 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: ticlopidine HCl oral film coated tablets, ticlopidine HCl oral film coated tablets. Sandoz Inc (per DailyMed), Princeton, NJ, 2008.
- Neumann FJ, Hall D, & Schomig A: Neutropenia with ticlopidine plus aspirin (letter). Lancet 1997; 349:1552-1553. PubMed
- Haushofer A, Halbmayer WM, & Prachar H: Neutropenia with ticlopidine plus aspirin (letter). Lancet 1997; 349:474-475. DOI
- Hobson AG & Sowinski KM: Ticlopidine and aspirin therapy following implantation of coronary artery stents. Ann Pharmacother 1997; 31:770-772.
- Thebault JJ, Blatrix CE, Blanchard JF, et al: The interactions of ticlopidine and aspirin in normal subjects. J Int Med Res 1977; 5:405-411. PubMed
Keep reading about Aspirin
Keep reading about Ticlopidine
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist