What is the recommended dosing regimen for dalteparin (low molecular weight heparin) in patients at high risk of clotting?

Dalteparin Dosing for High Clot Risk Patients

For patients at high risk of clotting, the recommended dalteparin dosing is 5,000 units subcutaneously once daily for prophylaxis, or weight-based dosing of 200 units/kg once daily for the first month followed by 150 units/kg once daily for months 2-6 for therapeutic treatment in cancer patients. 1

Prophylactic Dosing

Standard Prophylactic Dosing

• Inpatient/Outpatient Prophylaxis: 5,000 units subcutaneously once daily 1
• This dose is appropriate for most hospitalized patients with active cancer or other high clot risk factors

Special Populations Requiring Dose Adjustment

Renal Impairment

• Unlike other LMWHs, dalteparin at prophylactic doses does not require dose adjustment for renal impairment 2
• Studies have shown no bioaccumulation of prophylactic dalteparin (5,000 units daily) in patients with severe renal insufficiency (CrCl <30 mL/min) 2

Obesity

• Patients with BMI ≥40 kg/m² may require increased dosing to 5,000 units subcutaneously twice daily 3

Perioperative Management

• For high bleeding risk surgery: Last dose should be administered at least 24 hours before procedure 1
• For low bleeding risk surgery: Can resume full dose within 24 hours after procedure 1

Therapeutic Dosing for Cancer Patients

Extended VTE Treatment in Cancer

• Month 1: 200 units/kg subcutaneously once daily 1, 4
• Months 2-6: 150 units/kg subcutaneously once daily 1, 4
• Maximum single daily dose: not specified in guidelines, but clinical practice often caps at 18,000 units

Monitoring Requirements

• Routine monitoring of anti-Xa levels is not required except in special populations 3
• Monitor platelet counts periodically due to risk of heparin-induced thrombocytopenia 4
• Baseline CBC, renal function, and coagulation studies should be performed before initiating therapy 1

Risk Assessment for Thromboprophylaxis

High-Risk Outpatients on Chemotherapy

High risk is defined by combinations of the following factors 1:

• Active cancers with high VTE incidence (stomach, pancreas, lung, lymphoma, gynecologic, bladder, testicular)
• Prechemotherapy platelet count >300,000/mcL
• Prechemotherapy WBC >11,000/mcL
• Hemoglobin <10 g/dL
• Use of erythropoietic-stimulating agents
• BMI ≥35 kg/m²
• Prior VTE

Contraindications

Absolute Contraindications

• Active major bleeding
• Recent central nervous system bleed
• Intracranial or spinal lesion at high risk for bleeding
• History of heparin-induced thrombocytopenia 4
• Hypersensitivity to dalteparin or pork products 4

Relative Contraindications

• Chronic, clinically significant bleeding >48 hours
• Thrombocytopenia (platelets <50,000/mcL)
• Severe platelet dysfunction
• Recent major operation at high risk for bleeding
• Underlying hemorrhagic coagulopathy 1

Duration of Therapy

• Hospitalized patients: Throughout hospitalization 1, 3
• Surgical patients: At least 7-10 days 3
• Cancer patients with VTE: Extended treatment for 6 months 1
• Post-surgical prophylaxis: Consider extending to 4 weeks after major abdominal or pelvic surgery in cancer patients 1

Clinical Pearls and Pitfalls

• Common Pitfall: Underdosing obese patients. Consider weight-based or higher fixed dosing in these patients 3
• Caution: When using epidural or spinal anesthesia, dalteparin should be held for 24 hours before catheter placement/removal 3
• Important: Unlike other LMWHs, dalteparin at prophylactic doses appears safe in severe renal impairment without dose adjustment 2
• Note: For nocturnal hemodialysis patients, dalteparin may be less effective than unfractionated heparin due to the longer treatment duration 5

By following these evidence-based dosing recommendations, clinicians can effectively reduce the risk of thrombotic events in high-risk patients while minimizing bleeding complications.