Summary
Progressive thrombocytopenia may develop in as many as 5% of patients receiving heparin
anticoagulation. In these patients, the risk of thromboembolic complications as well
as continued thrombocytopenia necessitates discontinuation of heparin and initiation
of an alternative anticoagulant when indicated. The heparinoid Lomoparan (Org 10172)
is a mixture of several nonheparin low molecular weight glycosaminoglycans with proven
anticoagulant efficacy that is generally non-reactive with platelets in the presence
of plasma from patients with heparin induced thrombocytopenia, whereas standard heparin
will induce platelet aggregation. We evaluated the role of heparinoid as a potential
alternative anticoagulant in patients with heparin induced thrombocytopenia. During
a 6 month period, we identified six patients with heparin induced thrombocytopenia
who required an alternative parenteral anticoagulant, four as primary treatment for
specific medical problem, and two as anticoagulation during a necessary surgical procedure.
Heparinoid was used successfully in both medical and surgical patients requiring parenteral
anticoagulation. In no case was there an exacerbation of the thrombocytopenia nor
thromboembolic complications while on heparinoid therapy. Three of our patients sustained
hemorrhagic complications, predominantly in the post-surgical setting in association
with elevated anti-factor Xa levels and additional anticoagulant agents. We feel that
these results confirm the utility of heparinoid anticoagulation in a select subset
of patients with heparin induced thrombocytopenia who require continued parenteral
anticoagulation.
