title: Subcutaneous low-molecular-weight heparin compared with continuous intravenous heparin in the treatment of proximal-vein thrombosis.
abstract: BACKGROUND
  Low-molecular-weight heparin has a high bioavailability and a prolonged half-life in comparison with conventional unfractionated heparin. Limited data are available for low-molecular-weight heparin as compared with unfractionated heparin for the treatment of deep-vein thrombosis.
  
  
  METHODS
  In a multicenter, double-blind clinical trial, we compared fixed-dose subcutaneous low-molecular-weight heparin given once daily with adjusted-dose intravenous heparin given by continuous infusion for the initial treatment of patients with proximal-vein thrombosis, using objective documentation of clinical outcomes.
  
  
  RESULTS
  Six of 213 patients who received low-molecular-weight heparin (2.8 percent) and 15 of 219 patients who received intravenous heparin (6.9 percent) had new episodes of venous thromboembolism (P = 0.07; 95 percent confidence interval for the difference, 0.02 percent to 8.1 percent). Major bleeding associated with initial therapy occurred in 1 patient receiving low-molecular-weight heparin (0.5 percent) and in 11 patients receiving intravenous heparin (5.0 percent), a reduction in risk of 91 percent (P = 0.006). This apparent protection against major bleeding was lost during long-term therapy. Minor hemorrhagic complications were infrequent. Ten patients receiving low-molecular-weight heparin (4.7 percent) died, as compared with 21 patients receiving intravenous heparin (9.6 percent), a risk reduction of 51 percent (P = 0.049).
  
  
  CONCLUSIONS
  Low-molecular-weight heparin is at least as effective and as safe as classic intravenous heparin therapy under the conditions of this study and more convenient to administer. The simplified therapy provided by low-molecular-weight heparin may allow patients with uncomplicated proximal deep-vein thrombosis to be cared for in an outpatient setting.
authors.affiliation: Division of General Internal Medicine, University of Calgary, Alberta, Canada.
authors.forename: R D
authors.initials: RD
authors.lastname: Hull
authors.forename: G E
authors.initials: GE
authors.lastname: Raskob
authors.forename: G F
authors.initials: GF
authors.lastname: Pineo
authors.forename: D
authors.initials: D
authors.lastname: Green
authors.forename: A A
authors.initials: AA
authors.lastname: Trowbridge
authors.forename: C G
authors.initials: CG
authors.lastname: Elliott
authors.forename: R G
authors.initials: RG
authors.lastname: Lerner
authors.forename: J
authors.initials: J
authors.lastname: Hall
authors.forename: T
authors.initials: T
authors.lastname: Sparling
authors.forename: H R
authors.initials: HR
authors.lastname: Brettell
mesh_terms: D004311:Double-Blind Method; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007262:Infusions, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010314:Partial Thromboplastin Time; D012008:Recurrence; D012306:Risk; D013923:Thromboembolism / Q000188:drug therapy; D013924:Thrombophlebitis / Q000188:drug therapy* / Q000401:mortality
chemical_list: D006493:Heparin