Effect of Low-Molecular-Weight Heparin (Tinzaparin) and Unfractionated Heparin on Platelet Aggregation

A low-molecular-weight heparin (LMWH), when anti-IIa activity was compared. In the ex vivo part Tinzaparin, was compared with unfractionated heparin of the study, a significant enhancement of ADP-induced (UFH) for their effects on platelet aggregation in vitro and platelet aggregation was observed after i.v. administra ex vivo. Both heparins showed a dose-dependent proag- tion of both Tinzaparin and UFH with no difference in gregatory effect on ADP- and collagen-induced platelet potency. Subcutaneous administration of Tinzaparin in aggregation in vitro, but LMWH was less potent. The two different doses did not have any effect on platelet differences in potency between Tinzaparin and UFH de- activity. In conclusion, Tinzaparin appears, like other pended on how the compounds were compared. The most LMWHs, to have less proaggregatory effect on platelets pronounced difference was found when molar concentra- than UFH both in vitro and ex vivo.