Tinzaparin and Active bleeding

The use of heparin is contraindicated in patients with uncontrollable active bleeding, except when the bleeding is due to disseminated intravascular coagulation. Hemorrhage can occur at virtually any site in patients receiving heparin. An unexplained drop in hematocrit or blood pressure, or any other unexplained symptom, should lead to serious consideration of a hemorrhagic event. Therapy with heparin should be used with extreme caution in patients with known bleeding disorders or disease states that may predispose to hemorrhage during heparin administration, including hemophilia, thrombocytopenia, certain vascular purpuras, ulcerative gastrointestinal lesions, diverticulitis, ulcerative colitis, severe liver disease, subacute bacterial endocarditis, severe hypertension, myeloproliferative disorders, and threatened abortion. Blood coagulation tests (e.g., whole blood clotting time, activated partial thromboplastin time) should be performed at appropriate intervals during full-dose heparin administration. In addition, periodic platelet counts, hematocrits, and tests for occult blood in stool are recommended during the entire course of heparin therapy. There is usually no need to monitor coagulation parameters in patients receiving low-dose heparin, except in patients undergoing major surgery. For low molecular weight heparin (LMWH), coagulation tests such as prothrombin time (PT) and aPTT are relatively insensitive measures of LMWH activity and not suitable for routine monitoring. Anti-Factor Xa may be used to monitor the anticoagulant effect of LMWH in patients with significant renal impairment, abnormal coagulation parameters, or bleeding during therapy.