General surgery in high-risk patient

Dalteparin (Fragmin): 5,000 units SC 8 to 12 hours before surgery and once daily after surgery

Enoxaparin (Lovenox)*: 40 mg SC 1 to 2 hours before surgery and once daily after surgery; or 30 mg SC every 12 hours starting 8 to 12 hours after surgery

General surgery in moderate-risk patient

Dalteparin: 2,500 units SC 1 to 2 hours before surgery and once daily after surgery

Enoxaparin: 20 mg SC 1 to 2 hours before surgery and once daily after surgery

Nadroparin †: 2,850 units SC 2 to 4 hours before surgery and once daily after surgery

Tinzaparin (Innohep): 3,500 units SC 2 hours before surgery and once daily after surgery

Orthopedic surgery

Dalteparin: 5,000 units SC 8 to 12 hours before surgery, then once daily starting 12 to 24 hours after surgery; or 2,500 units SC 6 to 8 hours after surgery, then 5,000 units SC once daily

Enoxaparin: 30 mg SC every 12 hours starting 12 to 24 hours after surgery; or 40 mg SC once daily starting 10 to 12 hours after surgery

Nadroparin †: 38 units per kg SC 12 hours before surgery, 12 hours after surgery, and once daily on postoperative days 1, 2, and 3, then increase to 57 units per kg SC once daily

Tinzaparin: 75 units per kg SC once daily starting 12 to 24 hours after surgery; or 4,500 units SC 12 hours before surgery and once daily after surgery

Major trauma

Enoxaparin: 30 mg SC every 12 hours starting 12 to 36 hours after injury if the patient is hemostatically stable

For acute spinal cord injury, enoxaparin: 30 mg SC every 12 hours

Medical conditions

Dalteparin: 2,500 units SC once daily

Enoxaparin: 40 mg SC once daily

Nadroparin †: 2,850 units SC once daily