Thrombocytopenia found uncommonly during heparin therapy.

In a prospective study to determine the frequency of thrombocytopenia in patients treated with intravenous heparin sodium of porcine gut origin, only four of 120 patients with suspected venous thromboembolism showed a depression of the platelet count to below 150 x 10(9)/L. In two of these patients, heparin was not considered to be the cause of thrombocytopenia because the platelet count, which fell transiently, rose again while heparin therapy was continued. These results indicate that thrombocytopenia is an uncommon complication of anticoagulant therapy with heparin derived from porcine gut mucosa.