Drugs
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Enoxaparin (PK 10169) belongs to the group of low molecular weight heparins which have a greater bioavailability and longer half-life than unfractionated heparin, permitting less frequent subcutaneous administration. In well controlled trials in surgical venous thrombosis (DVT), enoxaparin has demonstrated prophylactic efficacy against venographically confirmed DVT at least equal to that observed with unfractionated heparin. Efficacy has also been demonstrated in patients at moderate risk and in limited investigations using 125I-fibrinogen scanning in nonsurgical patients at risk of DVT; in addition, enoxaparin appears to provide effective treatment of established DVT. In clinical studies, enoxaparin has also prevented coagulation of extracorporeal circulation, maintaining the patency of the circuit in patients undergoing haemodialysis. Thus, enoxaparin represents an effective alternative in the prophylaxis and treatment of thrombosis, with the convenience of less frequent administration than unfractionated heparin and the possible advantage of a lesser propensity for bleeding complications. ⋯ In prevention of postoperative DVT in patients undergoing orthopaedic surgery, subcutaneous enoxaparin doses of 40mg once daily (from 12 hours preoperatively) are employed in Europe, while a dosage of 30mg twice daily (from 12 to 24 hours postoperatively) has been used in North America; in general surgery and in 'moderate risk' patients dosages of 20mg once daily have also been employed. Enoxaparin 2 mg/kg/day is effective in the treatment of established DVT, while 1 mg/kg appears to be effective in preventing coagulation of the extracorporeal circuit in patients undergoing haemodialysis. For daily dosages higher than 60mg, the elimination of enoxaparin may be prolonged in patients with severe renal dysfunction; however, an appropriate nomogram for dosage reduction has not yet been devised.