International Normalized Ratio (INR) Targets: Venous Thromboembolism 

Updated: Apr 18, 2019
Author: Kevin Ting, MD;

INR Targets in Venous Thromboembolism

The guidelines below are based on the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines for Antithrombotic Therapy and Prevention of Thrombosis (ninth edition, 2012).[1]

Acute pulmonary embolism (PE)[2, 3]

International normalized ratio (INR) target (range)

  • Standard: 2.5 (2.0-3.0)

  • Unprovoked, infrequent INR checks: 1.5-1.9 after 3 months of standard therapy

Duration of therapy

  • Transient, reversible risk factor: 3 months

  • First episode, unprovoked

    • Low/moderate bleeding risk: Extended therapy

    • High bleeding risk: 3 months

  • Recurrent, unprovoked

    • Low/moderate bleeding risk: extended therapy

    • High bleeding risk: 3 months

  • Cancer: Extended therapy

Acute deep venous thrombosis (DVT) of the lower extremity

INR target (range)

  • Standard: 2.5 (2.0-3.0)

Duration of therapy

  • Transient, reversible risk factor: 3 months

  • First episode, unprovoked, proximal

    • Low/moderate bleeding risk: Extended therapy

    • High bleeding risk: 3 months

  • First episode, unprovoked, distal: 3 months (guidelines suggest serial imaging for 2 weeks rather than early anticoagulation for patients with isolated distal lower-extremity DVT who do not have severe symptoms or risk factors for extension)

  • Recurrent, unprovoked

    • Low/moderate bleeding risk: Extended therapy

    • High bleeding risk: 3 months

  • Cancer: Extended therapy

Acute DVT of the upper extremity

INR target (range): 2.5 (2.0-3.0)[4]

Duration of therapy

  • Axillary or more proximal: 3 months or more

  • Distal: 3 months

  • Central venous catheter (CVC) related: Until catheter is removed, or a minimum of 3 months

Acute DVT in children

INR target (range)[5]

  • Standard: 2.5 (2.0-3.0)

  • CVC related: 1.5-1.9 after 3 months of standard therapy

Duration of therapy

  • Idiopathic, first episode: 6-12 months

  • Idiopathic, recurrent: Lifelong therapy

  • Reversible risk factor: Until risk factor has resolved, or a minimum of 3 months

  • Cancer, thrombophilia: Until risk factor has resolved, or a minimum of 3 months

  • CVC related: Until CVC is removed, or a minimum of 3 months