What are the nonhemorrhagic side effects of heparin?
The main nonhemorrhagic side effects of heparin are HIT and osteoporosis. HIT is caused by IgG subclass, heparin-dependent antibodies. These antibodies bind to a conformationally modi ed epitope on platelet factor 4 (PF4). Simultaneous binding of these antibodies to Fc receptors on the platelet sur- face causes platelet activation. Activated platelets shed highly prothrombotic microparticles and are then removed from the circulation causing thrombocytopenia. In addition, these activated platelets and microparticles provide a surface onto which coagulation factor complexes can assemble to promote thrombin generation.