Drug Reduces Clotting Risk After Hip Replacement
Rate of venous thromboembolism reduced in a dose-response manner with increasing doses of SR123781A
MONDAY, April 7 (HealthDay News) -- A synthetic oligosaccharide with anti-factor Xa and IIa activities reduces the rate of venous thromboembolism after hip replacement surgery, researchers report in the April 15 issue of the Journal of the American College of Cardiology.
Michael R. Lassen, M.D., from Horsholm Hospital in Horsholm, Denmark, and colleagues randomly assigned 1,023 patients undergoing total hip replacement surgery to one of five doses of SR123781A (0.25 to 4.0 mg) or 40 mg of enoxaparin per day.
The researchers found that the rate of venous thromboembolism was reduced in a dose-response manner with increasing doses of SR123781A from 21.2 percent at 0.25 mg to 4.4 percent at 4.0 mg, compared with 8.7 percent in the enoxaparin group. The risk of venous thromboembolism was reduced by 67 percent at 2.0 mg SR123781A and by 79 percent at 4.0 mg SR123781A compared with the lowest dose. However, the rate of major bleeding was significant and dose-dependent, occurring in 0.6 percent of patients receiving 2.0 mg SR123781A and in 5.8 percent of patients receiving 4.0 mg SR123781A compared with 0.6 percent of enoxaparin patients.
"The model based on these dose-finding study results suggests that SR123781A doses ranging from 1.5 to 2.5 mg show a reasonable risk-to-benefit ratio for venous thromboembolism prevention after major orthopedic surgery," Lassen and colleagues conclude.
The study was funded by an unrestricted grant from Sanofi-Aventis, and the study authors disclose financial relationships with several pharmaceutical companies.