Intravenous warfarin and heparin-induced thrombocytopenia: making the diagnosis, management, modern monitoring, and multidisciplinary care

Ann Pharmacother. 2014 Feb;48(2):286-91. doi: 10.1177/1060028013511060. Epub 2013 Nov 6.


Objective: To describe the diagnosis, management, and monitoring of a patient with heparin-induced thrombocytopenia (HIT) with thrombosis and simultaneous bleeding risk treated with argatroban and transitioned to intravenous (IV) warfarin secondary to the inability to administer enteral medications.

Case summary: A 71-year-old man was admitted to the surgical intensive care unit (SICU) following aortic valve repair, coronary artery bypass, and ascending aortic aneurysm repair. On postoperative day 9, he was found to have a pulmonary embolism, and therapeutic heparin was started. The following day, his platelet count was found to have dropped precipitously. HIT was diagnosed, heparin was discontinued, and argatroban was initiated. On postoperative day 22, anticoagulation was discontinued because of massive gastrointestinal bleeding. On postoperative day 35, multiple venous thromboses were found, and argatroban was restarted. The patient developed a high-output enterocutaneous fistula, eliminating the option of enteral route of medication administration. The multidisciplinary SICU team transitioned the patient from argatroban to IV warfarin for long-term anticoagulation. The international normalized ratio was monitored and remained therapeutic throughout his admission without further thrombotic complications.

Discussion: HIT occurs when antibodies develop to heparin-platelet factor 4 complexes, causing simultaneous hypercoagulability and thrombocytopenia. It is diagnosed based on both clinical factors and laboratory testing. Treatment includes discontinuation of all forms of heparin; initiation of a nonheparin anticoagulant, such as argatroban; and transition to warfarin.

Conclusions: IV warfarin is a therapeutic option for patients with malabsorption issues. A multidisciplinary team in an intensive care setting optimizes cost-effective, patient-centered, and safe care.

Keywords: IV warfarin; heparin-induced thrombocytopenia; malabsorption.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Anticoagulants / adverse effects*
  • Antithrombins / therapeutic use
  • Arginine / analogs & derivatives
  • Cardiac Surgical Procedures / adverse effects
  • Hemorrhage / chemically induced
  • Hemorrhage / diagnosis
  • Hemorrhage / drug therapy
  • Heparin / adverse effects*
  • Humans
  • Infusions, Intravenous
  • Male
  • Pipecolic Acids / therapeutic use
  • Pulmonary Embolism / drug therapy
  • Sulfonamides
  • Thrombocytopenia / chemically induced*
  • Thrombocytopenia / diagnosis
  • Thrombocytopenia / drug therapy
  • Thrombosis / chemically induced
  • Thrombosis / diagnosis
  • Thrombosis / drug therapy
  • Warfarin / adverse effects*


  • Anticoagulants
  • Antithrombins
  • Pipecolic Acids
  • Sulfonamides
  • Warfarin
  • Heparin
  • Arginine
  • argatroban