VTE treatment | VTE prophylaxis | Product labeling on use in patients with a high BMI | |
Enoxaparin* | Use standard treatment dosing (ie, 1 mg/kg every 12 hours based on TBW).¶ Once-daily dosing regimens of enoxaparin are not recommended.[1] | BMI 30 to 39 kg/m2: Use standard prophylaxis dosing (ie, 30 mg every 12 hours or 40 mg once daily).[2] Some experts use weight-based dosing (ie, 0.5 mg/kg based on TBW once or twice daily, depending upon level of VTE risk).Δ[3,4] BMI ≥40 kg/m2: Empirically increase standard prophylaxis dose by 30% (ie, from 30 mg every 12 hours to 40 mg every 12 hours).◊[2] Some experts use weight-based dosing (ie, 0.5 mg/kg based on TBW once or twice daily, depending upon level of VTE risk).Δ[3-7] High VTE-risk bariatric surgery with BMI ≤50 kg/m2: 40 mg every 12 hours.§[8,9] High VTE-risk bariatric surgery with BMI >50 kg/m2: 60 mg every 12 hours.§[9] | Safety and efficacy of prophylactic doses in patients with obesity (BMI >30 kg/m2) has not been fully determined, and there is no consensus for dose adjustment. Observe carefully for signs and symptoms of VTE.[10] Marginal increase observed in mean anti-factor Xa activity using TBW and 1.5 mg/kg once-daily dosing in healthy persons with obesity (BMI 30 to 48 kg/m2) compared with healthy persons with lower BMI.[10] |
Dalteparin | Use standard treatment dosing (ie, 200 units/kg once daily based on TBW for the first month, followed by 150 units/kg TBW once daily for subsequent months).¶¥ May consider using 100 units/kg based on TBW every 12 hours for patients weighing ≥90 kg.[11] The labeled indication in the United States for adult patients is extended treatment of cancer-associated VTE.[12] | BMI 30 to 39 kg/m2: Use standard prophylaxis dosing (ie, 5000 units once daily).[2] BMI ≥40 kg/m2: Empirically increase standard prophylaxis dose by 30% (ie, from 5000 units once daily to 6500 units once daily).Δ◊[2] | Cancer-associated VTE treatment: Use TBW-based dosing for patients weighing up to 99 kg. Use a maximum dose of 18,000 units per day for patients weighing ≥99 kg.¶¥[12] |
Nadroparin (not available in the United States) | Use standard treatment dosing (ie, 171 anti-factor Xa units/kg once daily based on TBW or 86 units/kg every 12 hours based on TBW).¶‡ | BMI 30 to 39 kg/m2: For orthopedic surgery, use weight-based dosing (ie, 38 anti-factor Xa units/kg once daily based on TBW increasing on postoperative day 4 to 57 anti-factor Xa units/kg once daily); for general surgery use standard fixed dosing (ie, 2850 anti-factor Xa units once daily); for medically ill patients use standard fixed dosing (ie, 5700 anti-factor Xa units once daily provided TBW >70 kg).[2] BMI ≥40 kg/m2: For orthopedic surgery, use weight-based dosing (ie, 38 anti-factor Xa units/kg once daily based on TBW increasing on postoperative day 4 to 57 anti-factor Xa units/kg once daily); for general surgery, empirically increase fixed dose by ~30% (ie, increase from 2850 to 3800 anti-factor Xa units once daily); for medically ill patients, empirically increase fixed dose by ~30% (ie, increase from 5700 to 7400 anti-factor Xa units once daily provided TBW >70 kg).Δ◊[2] | Safety and efficacy of LMWHs in high-weight (ie, >120 kg) patients has not been fully determined. Individualized clinical and laboratory monitoring is recommended (Canada product monograph).[13] VTE treatment: Use TBW-based dosing for patients weighing up to 100 kg. Use a maximum dose of 17,100 anti-Xa units per day for patients weighing >100 kg.¶‡[13] |
Tinzaparin (not available in the United States) | Use standard treatment dosing (ie, 175 anti-factor Xa units/kg once daily based on TBW).¶ | BMI 30 to 39 kg/m2: For orthopedic surgery, use weight-based prophylaxis dosing (ie, 50 or 75 anti-factor Xa units/kg based on TBW once daily); for general surgery and medically ill patients, use standard fixed dosing (ie, 3500 or 4500 anti-factor Xa units once daily depending upon level of VTE risk).[2] BMI ≥40 kg/m2: For orthopedic surgery, use weight-based prophylaxis dosing (ie, 50 or 75 anti-factor Xa units/kg based on TBW once daily); for general surgery and medically ill patients, empirically increase fixed dose by 30% (ie, increase from 3500 to 4500 anti-factor Xa units once daily or from 4500 to 6000 anti-factor Xa units once daily depending on level of VTE risk).Δ◊[2] Moderate to high VTE-risk bariatric surgery, extended postoperative prophylaxis regimen: According to a protocol evaluated at one center: Beginning on postoperative day 1: 75 units/kg based on TBW once daily for 10 days; patients weighing <110 kg received 4500 units once daily; patients weighing ≥160 kg received 14,000 units once daily.Δ§[14] | Safety and efficacy in patients weighing >120 kg has not been fully determined. Individualized clinical and laboratory monitoring is recommended (Canada product monograph).[15] |
All doses shown are for patients with normal kidney function and are for subcutaneous administration. For dose adjustment due to kidney impairment, refer to Lexicomp monographs.
Generally, anti-factor Xa monitoring is not recommended, but it can be considered for patients with BMI ≥40 kg/m2 who are unstable, experience unexpected thromboembolic or bleeding complications, or require prolonged VTE treatment.VTE: venous thromboembolism; TBW: total body weight, also known as actual body weight; LMWH: low molecular weight heparin; FDA: Food and Drug Administration.
* Conversion: 1 mg enoxaparin is approximately equal to 100 international units enoxaparin.
¶ The 2018 American Society of Hematology (ASH) guidelines and other expert reviews suggest against dose reduction or use of a maximum dose for VTE treatment in patients with a high BMI citing consequences of therapeutic failure and lack of correlation between anti-factor Xa concentrations and increased bleeding risk.[2,16]
Δ Rounding of the dose may be necessary depending on product detail. Refer to Lexicomp monograph included with UpToDate.
◊ An empiric dose increase of approximately 30% for fixed prophylactic doses of LMWH for VTE prophylaxis for patients with a high BMI is based on clinical experience, expert opinion, and analysis of pharmacodynamic and clinical outcomes data.[2]
§ An optimal approach to thromboprophylaxis in bariatric surgery patients has not been established; there is considerable variability in approach among surgeons and programs. For additional information refer to UpToDate topics on bariatric surgery and institutional protocols.
¥ According to the US FDA approved dalteparin prescribing information, a fixed dose of 18,000 units per day is recommended for patients weighing ≥99 kg who are being treated for cancer-associated VTE.[12] However, guidelines suggest that dalteparin dose should be based on TBW.[2,15] Capped dalteparin dose of 18,000 units per day is not recommended.
‡ According to the Canadian approved nadroparin product monograph, a fixed dose of 17,100 units per day is recommended for patients weighing more than 100 kg.[13] However, guidelines suggest that nadroparin dose should be based on TBW.[2,16] Capped nadroparin dose of 17,100 units per day is not recommended.