Prevention of coagulation during hemodialysis by a combination of the stable prostacyclin analogue CG 4203 and low-dose heparin.

In certain situations heparin used during hemodialysis can increase the risk of bleeding. Various groups have suggested that this bleeding risk can be reduced by using prostacyclin (PGI2). Since PGI2 is labile under physiological conditions and is thus difficult to use, we have used the stable PGI2 analogue CG 4203. This study in 5 chronic dialysis patients was designed to apply the following 5 different dialysis regimens with bicarbonate to each patient for 5 h: 1) conventional full heparinization; 2) CG 4203 (25 ng/kg/min) for the first 120 min, then full heparinization; 3) CG 4203 alone for 5 h (25 ng/kg/min); 4) initial bolus dose of heparin (500 IU), then continuous infusion of heparin (200 IU/h) and CG 4203 (25 ng/kg/min); 5) as 4) above but 35 ng/kg/min of CG 4203. Slight falls in thrombocytes and in some case substantial falls in leukocytes shortly after commencing the dialysis cannot be avoided when administering CG 4203 alone. Both 25 and 35 ng/kg/min doses of CG 4203 produced approx. 50% inhibition of the ADP-induced platelet aggregation for the entire 5 h administration period. At 30 min after dialysis the inhibition had fallen to approx. 20%. Although administering CG 4203 alone for 2 h produced no extracorporeal occlusion, administering CG 4203 alone for 5 h, some clots did occur after 3-5 h, which caused premature termination of the dialysis or made reinfusion impossible after 5 h. When 25 ng/kg/min was applied together with a continuous low dose of heparin for 5 h, only small clots were observed which did not impede dialysis or reinfusion.(ABSTRACT TRUNCATED AT 250 WORDS)