Heparin versus low molecular weight heparin K 2165 in chronic hemodialysis patients: a randomized cross-over study.

Ten patients on chronic intermittent hemodialysis treatment received either unfractionated heparin or low molecular weight (LMW) heparin K 2165 in a single-blinded randomized cross-over study to assess: effects on hemostasis and ex vivo platelet functions, and effectiveness, i.e. prevention of fibrin formation in the extracorporeal circuit. The 20 dialysis treatments were without untoward side effects, for both drugs used. The variation in the plasma anti-Xa activities was significantly less during K 2165 treatment than during heparinization. No differences between the drugs were observed regarding the Ivy bleeding time, platelet count and platelet aggregation (spontaneous, and induced by ADP and collagen). Plasma platelet factor 4 levels did not increase under K 2165 to such an extent as under heparin. Both drugs did not influence the plasma levels of beta-thromboglobulin, thromboxane B2 and platelet serotonin content. K 2165 did not affect platelet adhesion to collagen, in contrast to heparin which substantially inhibited platelet adhesion. Under both treatments, 4 minor clots were observed in 4 artificial kidneys, despite plasma anti-Xa levels in between 0.19 and 0.46 U/ml. K 2165 may therefore be considered as effective an anticoagulant as heparin, with less effects on ex vivo platelet functions.