Drug Points

Skin necrosis induced by warfarin treatment has been clearly associated with deficiency of both protein C and protein S. The rapid fall in protein C concentrations on starting warfarin treatment is thought to produce a hypercoaguable state leading to thrombosis. 2 Skin necrosis induced by heparin has been linked to a heparin induced platelet antibody that promotes platelet aggregation and the formation of thrombi. 3 Information on adverse reactions to all the thrombolytic enzymes details a total of 40 peripheral vascular problems including cases of arterial embolisation, thrombophlebitis, and vasculitis. 4 There are 28 reports of purpura and bruising. A raised serum creatine kinase concentration (1440 IU/I) has been previously reported in an agitated man receiving a therapeutic dose of thioridazine. 1 Rhabdomyolysis has also occurred in overdoses of other phenothiazines.2,3