heparin group drug pathway heparin drug pathway 2015-12-07T09:55:54Z PW:0002327 The pharmacokinetics and pharmacodynamics pathway of heparin, a naturally occurring anticoagulant produced by basophils and mast cells. Heparin, and its low molecular weight derivative, bind to and activates the thrombin enzyme inhibitor antithrombin III. Genetic variations can result in changes in drug availability and can cause differences in the response of the organism to the drug. pathway vpetri