A comparison of pentosan polysulphate and heparin. II: Effects of subcutaneous injection.

A comparison has been made between the effects of pentosan polysulphate (SP54) and mucosal heparin following subcutaneous injection in man. Unlike heparin, pentosan polysulphate has relatively little effect in vivo as measured by anti-factor Xa clotting assay and none by an anti-Xa amidolytic assay (S-2222). However, pentosan polysulphate is at least as potent as heparin on a weight basis in producing activation of lipoprotein lipase, shortening of the euglobulin clot lysis time and impairing the generation of factor Xa. Our data indicate that pentosan polysulphate has more marked effects in vivo than in vitro, that the action of the drug on clotting is mediated mainly via an At III-independent pathway, and that its effects are not confined to the coagulation system.