Drug Interaction Report

Vorapaxar and Dalteparin Injection: Interaction Details

A pharmacist-reviewed analysis of the Vorapaxar and Dalteparin Injection interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Vorapaxar

Zontivity Zontivity®
+

Dalteparin Injection

Fragmin Fragmin®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 55 documented Vorapaxar interactions, 50 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Increased risk of bleeding, including intracranial hemorrhage and fatal bleeding

Interaction Deep Dive

Avoid concomitant use of vorapaxar (antiplatelet agent) with anticoagulants as this may increase the risk of bleeding, including intracranial hemorrhage and fatal bleeding2. Promptly evaluate any signs or symptoms of blood loss if concomitant use of vorapaxar and anticoagulants are required 1.

Why it happens (mechanism)

Additive effects on hemostasis

Literature reports

1 report — tap to read

a) In two drug interaction studies where clopidogrel (antiplatelet agent) 300 mg loading dose followed by 75 mg daily maintenance dose and rivaroxaban (factor Xa inhibitor, anticoagulant) 15 mg single dose were coadministered in healthy subjects, an increase in bleeding time to 45 minutes was observed in approximately 45% and 30% of subjects in these studies, respectively. The change in bleeding time was approximately twice the maximum increase seen with either drug alone. There was no change in the pharmacokinetics of either drug 1.

Common questions

Can I take Vorapaxar and Dalteparin Injection together?

Increased risk of bleeding, including intracranial hemorrhage and fatal bleeding Always confirm with your pharmacist or prescriber before making any change.

How serious is the Vorapaxar and Dalteparin Injection 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Vorapaxar or Dalteparin Injection 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 (2)

  1. Product Information: XARELTO(R) oral tablets, oral suspension, rivaroxaban oral tablets, oral suspension. Janssen Pharmaceuticals Inc (per FDA), Titusville, NJ, 2023. DailyMed
  2. Product Information: ZONTIVITY(R) oral tablets, vorapaxar oral tablets. Merck Sharp & Dohme Corp. (per FDA), Whitehouse Station, NJ, 2015. DailyMed
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Vorapaxar

Keep reading about Vorapaxar

All Vorapaxar interactions (55) Vorapaxar drug information
Also serious with: Defibrotide Injection Colchicine Abrocitinib Betrixaban
Dalteparin Injection

Keep reading about Dalteparin Injection

All Dalteparin Injection interactions (177) Dalteparin Injection drug information
Also serious with: Defibrotide Abciximab Aceclofenac Acemetacin
Beyond drug–drug

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:

Vorapaxar + Activated Charcoal Danshen Grapefruit Piracetam St. John's Wort Acacia Rigidula Aconite Adrafinil + 274 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.