A STUDY OF THE ANTI-THROMBOTIC POTENTIAL OF LOW MOLECULAR WEIGHT HEPARIN LHN-1 (NOVO) IN NORMAL VOLUNTEERS
Studies of low molecular weight heparin have shown a molecular sized dependency of the anti-coagulant activity. We studied the effects of a low molecular weight heparin LHN-1 (Novo) with a mean molecular weight of 5-7000 daltons on the coagulation mechanism and platelet function of normal volunteers. The heparin was given for 5 days on a once daily dose of 2500, 5000 or 7500 anti-Xa units to 3 groups of volunteers and in a twice daily regime of 2500 and 5000 anti-Xa units in 2 further groups of volunteers. After subcutaneous injection LHN-1 produced a significant (p<0.01) increase in anti-Xa activity which peaked between 3-4 hours after subcutaneous injection on both once and twice daily regime. On once daily regime there was no significant measure able anti-Xa activity 24 hours after the last injection. There was a small but significant increase in both KCCT and thrombin time (p<0.01) following injection, which was also dose related. Bleeding time did not change and there was no effect on platelet function. There was a significant (p<0.01) increase in fibrinolysis as measured by the fibrin plate method. There were no bleeding problems. These findings would suggest that LHN-1 merits further clinical evaluation to confirm its anti-thrombotic and profibrinolytic potential.