Two randomized, double-blind clinical trials comparing enoxaparin and fondaparinux started after orthopedic surgery
Trial and study drug . | No. study patients tested for anti-PF4/heparin antibodies (%)* . | Dosing regimen (timing of first dose after surgery) . | Median time from surgery to blood sampling for anti-PF4/heparin antibodies, d (IQR) . | Median time from first injection of study drug to blood sampling for anti-PF4/heparin antibodies, d†(IQR) . |
|---|---|---|---|---|
| Knee (PENTAMAKS)14 | ||||
| Enoxaparin | 365 (70.6) | 30 mg bid (12-24 h) | 5.72 (3.93, 6.78) | 4.82 (2.92, 5.88) |
| Fondaparinux | 388 (75.0) | 2.5 mg od (4-8 h) | 5.71 (3.93, 6.74) | 5.34 (3.55, 6.38) |
| Hip (PENTATHLON)15 | ||||
| Enoxaparin | 984 (87.2) | 30 mg bid (12-24 h) | 5.77 (4.61, 6.82) | 4.88 (3.77, 5.88) |
| Fondaparinux | 989 (87.7) | 2.5 mg od (4-8 h) | 5.81 (4.65, 6.84) | 5.42 (4.29, 6.47) |
Trial and study drug . | No. study patients tested for anti-PF4/heparin antibodies (%)* . | Dosing regimen (timing of first dose after surgery) . | Median time from surgery to blood sampling for anti-PF4/heparin antibodies, d (IQR) . | Median time from first injection of study drug to blood sampling for anti-PF4/heparin antibodies, d†(IQR) . |
|---|---|---|---|---|
| Knee (PENTAMAKS)14 | ||||
| Enoxaparin | 365 (70.6) | 30 mg bid (12-24 h) | 5.72 (3.93, 6.78) | 4.82 (2.92, 5.88) |
| Fondaparinux | 388 (75.0) | 2.5 mg od (4-8 h) | 5.71 (3.93, 6.74) | 5.34 (3.55, 6.38) |
| Hip (PENTATHLON)15 | ||||
| Enoxaparin | 984 (87.2) | 30 mg bid (12-24 h) | 5.77 (4.61, 6.82) | 4.88 (3.77, 5.88) |
| Fondaparinux | 989 (87.7) | 2.5 mg od (4-8 h) | 5.81 (4.65, 6.84) | 5.42 (4.29, 6.47) |
IQR indicates interquartile range; bid, twice daily; od, once daily.
Percent of study patients given at least one dose of study drug.
The difference in the median number of days between first injection of anticoagulant to blood sampling for anti—PF4/heparin antibodies differs between patients receiving enoxaparin and fondaparinux (right column) because of the trial design, in which fondaparinux was started 4 to 8 hours after surgery, whereas enoxaparin was started 12 to 24 hours after surgery.