DVT Prophylaxis Dose of Clexane (Enoxaparin)
The recommended dose of Clexane (enoxaparin) for DVT prophylaxis in patients with normal renal function is 40 mg subcutaneously once daily. 1
Standard Prophylactic Dosing
- Enoxaparin 40 mg subcutaneously once daily is the established prophylactic dose for both medical and surgical patients with normal renal function 1, 2
- This dosing should continue for the duration of hospital stay or until the patient is fully ambulatory for medical patients 1
- For surgical patients, prophylaxis should last at least 7-10 days 1
Timing of Administration
- Start enoxaparin 2-4 hours preoperatively for standard surgical cases 1, 2
- Start 10-12 hours preoperatively if neuraxial anesthesia is planned 1, 2
- Avoid administration within 10-12 hours before spinal/epidural procedures to reduce the risk of spinal hematoma 1, 2
Critical Dose Adjustments for Special Populations
Renal Impairment
- For severe renal impairment (CrCl <30 mL/min): reduce to 30 mg subcutaneously once daily 1, 2, 3
- Enoxaparin clearance is reduced by 44% in severe renal impairment, leading to drug accumulation and significantly increased bleeding risk without dose adjustment 1, 3
- For moderate renal impairment (CrCl 30-50 mL/min), consider dose reduction as clearance is reduced by 31% 1, 3
Obesity
- For patients with BMI >30 kg/m²: consider intermediate dosing of 40 mg subcutaneously every 12 hours or weight-based dosing of 0.5 mg/kg subcutaneously every 12 hours 1, 2
- For patients with body weight >150 kg, increase to 40 mg every 12 hours 2
Underweight Patients
- Standard fixed dosing may be excessive in patients weighing <50 kg 1
- Consider reduced dosing of 30 mg once daily, though both reduced and standard dosing appear effective in this population 4
Advantages Over Unfractionated Heparin
- Better bioavailability and longer half-life allowing once-daily administration 1, 2
- More predictable anticoagulation effect without need for routine laboratory monitoring 1, 2
- Lower risk of heparin-induced thrombocytopenia compared to unfractionated heparin 1, 2
- Lower risk of major bleeding and local hematomas 1, 5
Monitoring Requirements
- Routine coagulation monitoring is not necessary for most patients on prophylactic doses 1
- Monitor platelet counts every 2-3 days from day 4 to day 14 to screen for heparin-induced thrombocytopenia 1
- Anti-Xa monitoring is recommended for patients with severe renal impairment on prolonged therapy, with target range of 0.29-0.34 IU/mL for prophylactic dosing, measured 4-6 hours after the third or fourth dose 1, 3
Common Pitfalls to Avoid
- Failure to adjust dose in severe renal impairment leads to drug accumulation and up to 4-fold increase in major bleeding risk 3
- Improper timing with neuraxial anesthesia can cause catastrophic spinal hematoma 1, 2
- Using standard dosing in obese patients may result in inadequate prophylaxis 1
- Not checking creatinine clearance before initiating therapy is a critical oversight, as renal function determines dosing more than any other factor 1, 3
Special Clinical Considerations
- Enoxaparin is primarily eliminated renally, not hepatically, making elevated liver enzymes alone not a contraindication and no dose adjustment necessary 1
- In major trauma patients, withhold enoxaparin for 2-3 days and reassess risk-benefit before initiating 2
- For high bleeding risk patients, consider mechanical prophylaxis (graduated compression stockings or intermittent pneumatic compression) instead 2