ATIII Activators Adverse Effects

Activators of Antithrombin III: HEPARIN,
FONDAPARINUX, LMW HEPARINS: DALTEPARIN, DANAPAROID, ENOXAPARIN

BLEEDING (esp. hemorrhagic stroke)
HYPERSENSITIVITY (rare even for HEPARIN now that there are more purified versions)
HEPARIN-INDUCED THROMBOCYTOPENIA (HIT)
- can result in pulmonary embolism, acute thrombotic stroke, or heart attacks (30% mortality)
- can cause thrombosis (paradoxical), initial arterial due to HEPARIN, can become venous if WARFARIN is given
- transient form occurs in about 25% of the patients during first 5 days of treatment
- severe HIT occurs in 5% of patients due to antibody-mediated thrombocytopenia (takes 5-10 days to develop; less time if it is a re-exposure)
  - in those patients, HEPARIN should be discontinued, and treatment initiated with HIRUDIN or LEPIRUDIN, but not WARFARIN (may exacerbate the prothrombotic state, causing venous limb gangrene and increased skin necrosis --- see WARFARIN)