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Fluctuations in anti-factor Xa levels with therapeutic enoxaparin anticoagulation in pregnancy

Journal of Perinatology volume 30, pages 253–257 (2010)Cite this article

Abstract

Objective:

The objective of the study was to evaluate anti-factor Xa levels with therapeutic enoxaparin anticoagulation in pregnancy.

Study Design:

A total of 15 pregnant subjects on therapeutic doses of enoxaparin (1 mg/kg ±20% subcutaneously (s.c.) twice daily (b.i.d.)) were enrolled prospectively in this cross-sectional pilot project. Three blood levels for anti-factor Xa activity were examined: before the enoxaparin dose (trough), 3- to 4-h later (peak) and 8-h later. Anti-factor Xa activity level between 0.5 and 1.2 U/ml was considered therapeutic.

Result:

Mean anti-factor Xa activity levels were: trough 0.45±0.18, peak 0.9±0.25 and 8-h after dose 0.72±0.23 U/ml. All peak levels were therapeutic; 20% (3/15) of the 8 h and 73% (11/15) of the trough levels were sub-therapeutic.

Conclusion:

Trough and 8-h post-dose anti-factor Xa activity levels were sub-therapeutic in a substantial number of patients receiving a b.i.d. regimen of therapeutic enoxaparin.

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Acknowledgements

We are grateful to Pamela Rumney, RNC and Anita Shell, RNC for their assistance in the conduct of this analysis. Clinical Trials.gov ID: NCT00319176. The funding for this study was provided by the Memorial Health Care Foundation (Research Grant no. 162-04).

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Author notes

  1. Long Beach Memorial Medical Center/Miller Children's Hospital, Long Beach, CA, USA

Authors and Affiliations

  1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of California,

    E Friedrich & A B Hameed

  2. Irvine, Orange, CA, USA

    E Friedrich & A B Hameed

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  1. E Friedrich
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  2. A B Hameed
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Correspondence to E Friedrich.

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Friedrich, E., Hameed, A. Fluctuations in anti-factor Xa levels with therapeutic enoxaparin anticoagulation in pregnancy. J Perinatol 30, 253–257 (2010). https://doi.org/10.1038/jp.2009.164

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