FPIN's Help Desk Answers

High-Dose vs. Standard-Dose Heparin for VTE Prophylaxis in Obese Patients


Am Fam Physician. 2018 Jun 1;97(11):online.

Clinical Question

Is high-dose heparin better than standard-dose heparin in reducing the incidence of venous thromboembolism (VTE) in obese inpatients?

Evidence-Based Answer

In most patients weighing more than 220 lb (100 kg), high-dose heparin prophylaxis (7,500 units subcutaneously three times per day) does not further reduce the risk of VTE compared with standard-dose heparin (5,000 units subcutaneously two or three times per day). In patients with a body mass index (BMI) greater than 40 kg per m2, higher doses of heparin or enoxaparin (Lovenox) reduce VTE risk more than standard doses of heparin or enoxaparin. (Strength of Recommendation: B, based on retrospective cohort studies.)

Evidence Summary

A 2016 retrospective cohort study included 2,378 obese adult inpatients receiving subcutaneous heparin for VTE prophylaxis.1 The patients were divided into high-dose (7,500 units three times per day; n = 196) and standard-dose (5,000 units three times per day; n = 2,182) groups. Patients were excluded if they were receiving enoxaparin or therapeutic anticoagulation; if they were admitted with VTE or bleeding; if they were pregnant, peripartum, imprisoned, or paraplegic; if they had a history of heparin-induced thrombocytopenia; or if they underwent surgery. Major bleeding was defined as a hemoglobin decrease of at least 2 g per dL (20 g per L) in 24 hours, transfusion of at least two units of blood products, or critical bleeding (e.g., intracranial, gastrointestinal). Any documented bleeding that did not meet the criteria for major bleeding was considered minor bleeding. Rates of VTE within 30 days of hospitalization did not differ significantly between the high-dose and standard-dose groups (1.0% vs. 0.23%, respectively; P = .05), nor did rates of major or minor bleeding (0% vs. 0.09%; P = .67).

A 2014 retrospective cohort study of adult medical and surgical inpatients weighing at least 220 lb compared 2,461 patients receiving sub-cutaneous high-dose heparin (7,500 units three

Address correspondence to Amy Haver, PharmD, BCPS, at haverae3@upmc.edu. Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.


1. Beall J, Woodruff A, Hempel C, Wovkulich M, Zammit K. Efficacy and safety of high-dose subcutaneous unfractionated heparin prophylaxis for the prevention of venous thromboembolism in obese hospitalized patients. Hosp Pharm. 2016;51(5):376–381.

2. Wang TF, Milligan PE, Wong CA, et al. Efficacy and safety of high-dose thromboprophylaxis in morbidly obese inpatients. Thromb Haemost. 2014;111(1):88–93.

3. Joy M, Tharp E, Hartman H, et al. Safety and efficacy of high-dose unfractionated heparin for prevention of venous thromboembolism in overweight and obese patients. Pharmacotherapy. 2016;36(7):740–748.

Help Desk Answers provides answers to questions submitted by practicing family physicians to the Family Physicians Inquiries Network (FPIN). Members of the network select questions based on their relevance to family medicine. Answers are drawn from an approved set of evidence-based resources and undergo peer review. The strength of recommendations and the level of evidence for individual studies are rated using criteria developed by the Evidence-Based Medicine Working Group (http://www.cebm.net).

The complete database of evidence-based questions and answers is copyrighted by FPIN. If interested in submitting questions or writing answers for this series, go to http://www.fpin.org or e-mail: questions@fpin.org.

This series is coordinated by John E. Delzell Jr., MD, MSPH, Associate Medical Editor.

A collection of FPIN's Help Desk Answers published in AFP is available at https://www.aafp.org/afp/hda.



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