A 61-year-old white man arrived at the emergency department with complaints of
pain in his left thigh that worsened with walking. His medical history was significant for extensive
thromboses over a period of six months. He had recently been discharged from the hospital for suspected
heparin-induced
thrombocytopenia (HIT) while on
enoxaparin. A venous duplex scan revealed two new
deep venous thromboses in the left common, superficial, and popliteal veins. The patient was admitted and initiated on
aspirin 325 mg and
warfarin sodium 2 mg daily. Intravenous
lepirudin with an activated partial thromboplastin time (aPTT) goal of 60-80 seconds was also started. Because of his recurrent thrombotic event, a new International Normalized Ratio (INR) goal of 3.0-3.5 was established for
warfarin therapy. Eighteen days after admission, the patient's INR and aPTT were high; therefore, his
warfarin dose was reduced and i.v.
lepirudin was changed to subcutaneous administration. The patient was transferred to the intensive care unit (ICU) and, 5 days later, he developed
melena. During the 7 days of treatment with subcutaneous
lepirudin, a drop in platelet counts was observed. Subcutaneous
lepirudin was discontinued after resolution of
melena, and i.v.
lepirudin was restarted. After 15 days, his platelet counts increased and he was switched back to subcutaneous
lepirudin, which again led to a drop in platelets. After 27 days in the ICU, the patient's INR and aPTT remained high.
Lepirudin was discontinued and i.v.
bivalirudin was initiated. His platelet count increased and he was discharged. Eleven days later, the patient was found unresponsive with left-sided
fasciculations. The patient died secondary to respiratory arrest as a consequence of
intracranial hemorrhage.
CONCLUSION: A 61-year-old white man with a history of
thromboses and suspected HIT developed
thrombocytopenia possibly associated with receiving two courses of subcutaneous
lepirudin. Careful monitoring of platelet counts are warranted in patients who have a history of HIT and are receiving subcutaneous
lepirudin.