Low-molecular-weight heparins (LMWHs), like unfractionated heparin (UFH), exert their action primarily by accelerating the interaction between antithrombin (AT) and thrombin. At the levels of aXa activity that are attained in human pharmacology, it does not cause significant (>15%) inhibition of the clotting system. The essential differences between LMWHs and UFH are: (a) LMWHs attain higher plasma concentrations after subcutaneous injection (high bioavailability), and (b) in contrast to LMWHs, UFH contains very large heparin molecules with a putative hemorrhagic action. The reputedly higher aXa activity of LMWH can be shown to be largely due to the absence of Ca(2+) using the current laboratory methods to estimate this activity. Via this artifact the apparently high aXa activity of LMWHs is correlated but not related to their favorable pharmacokinetic properties. Consequently dosage guidelines for the use of different LMWHs cannot be based upon their aXa activity. Until better laboratory methods are available, clinical results are the only reliable guideline to heparin dosage.

Download full-text PDF

Source
http://dx.doi.org/10.1159/000022497DOI Listing

Publication Analysis

Top Keywords

axa activity
16
lmwhs ufh
8
laboratory methods
8
activity
6
lmwhs
6
conjectures refutations
4
refutations mode
4
mode action
4
action heparins
4
heparins limited
4

Similar Publications

Current Advances in Behavioral Addictions: From Fundamental Research to Clinical Practice.

Am J Psychiatry

December 2024

General Psychology-Cognition, Faculty of Computer Science, University of Duisburg-Essen, Germany (Brand, Antons, Wegmann); Center for Behavioral Addiction Research, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Germany (Brand, Antons, Wegmann); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany (Brand, Antons); Department of Psychology, University of Montreal, Montreal (Bőthe); Interdisciplinary Research Center on Intimate Relationship Problems and Sexual Abuse (CRIPCAS), Montreal (Bőthe); College of Education, Psychology, and Social Work, Flinders University, Adelaide, Australia (Demetrovics, King); Institute of Psychology, ELTE Eötvös Loránd University, Budapest (Demetrovics); Center of Excellence in Responsible Gaming, University of Gibraltar, Gibraltar (Demetrovics); School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK (Fineberg); Hertfordshire Partnership University NHS Foundation Trust, Welwyn Garden City, UK (Fineberg); University of Cambridge School of Clinical Medicine, Cambridge, UK (Fineberg); Department of Clinical Psychology, Bellvitge University Hospital, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona (Jimenez-Murcia); Ciber Physiopathology of Obesity and Nutrition, Instituto de Salud Carlos III, Barcelona (Jimenez-Murcia); Psychoneurobiology of Eating and Addictive Behaviors Group, Neurosciences Program, IDIBELL, Barcelona (Jimenez-Murcia); Department of Clinical Sciences, School of Medicine and Health Sciences, University of Barcelona, Barcelona (Jimenez-Murcia); Psychology Services of the University of Barcelona, Barcelona (Jimenez-Murcia); Instituto de Investigación, Transferencia e Innovación, Universidad Internacional de La Rioja, La Rioja, Spain (Mestre-Bach); Department of General Psychology, University of Padova, Padua, Italy (Moretta); Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hanover, Germany (Müller); Departments of Psychiatry, Neuroscience, and Child Study and Wu Tsai Institute, Yale University School of Medicine, New Haven, CT (Potenza); Connecticut Council on Problem Gambling, Wethersfield, CT (Potenza); Connecticut Mental Health Center, New Haven, CT (Potenza).

Article Synopsis
  • Gambling disorder is the only recognized behavioral addiction in DSM-5, while Internet gaming disorder is noted for further research; other potential disorders include compulsive sexual behavior, compulsive shopping, and social media issues.
  • These disorders are clinically relevant and often coexist with conditions like depression and anxiety, with validated diagnostic tools available but no approved medications for treatment.
  • Cognitive-behavioral therapy shows the most promise, highlighting the need for active screening and public health efforts, along with further research into treatment methods that combine various therapeutic approaches.
View Article and Find Full Text PDF
Article Synopsis
  • Direct oral anticoagulants (DOACs), particularly factor Xa (FXa) inhibitors, are used in patients with chronic thromboembolic pulmonary hypertension (CTEPH) for secondary prevention after venous thromboembolism, though data on their effects are limited.
  • A study involving 50 CTEPH patients analyzed the anti-factor Xa activity (AXA) of different FXa inhibitors (rivaroxaban, apixaban, edoxaban) and found that apixaban had significantly higher trough AXA levels compared to rivaroxaban and edoxaban.
  • Higher peak AXA levels (≥2.09 IU/mL) were associated with an increased risk of major bleeding, indicating that monitoring
View Article and Find Full Text PDF

Impact of COVID-19 Pandemic Interventions on Sudden Unexpected Death in Infancy Incidence in France.

J Pediatr

October 2024

Université de Paris, INSERM, ECEVE, Paris, France; Pediatrics Emergency Care Unit, AP-HP, Jean Verdier University Hospital, Université Sorbonne Paris Nord, Bondy, France.

Objective: To study the impact of nonpharmaceutical interventions implemented during the COVID-19 pandemic on the monthly incidence of sudden unexpected death in infancy (SUDI) cases overall and those with a viral or bacterial identification.

Study Design: We conducted an interrupted time-series analysis using seasonally adjusted Poisson regression models from the French national prospective and multicenter SUDI registry, that included all SUDI cases below the age of 1 year who died from 2016 to 2021 in mainland France.

Results: Of 998 SUDI cases analyzed, 750 were recorded during the prepandemic period (January 2016 through March 2020) and 248 during the NPI period (April 2020 through December 2021).

View Article and Find Full Text PDF

Background: Convalescent plasma (CP) reduced the mortality in COVID-19 induced ARDS (C-ARDS) patients treated in the CONFIDENT trial. As patients are immunologically heterogeneous, we hypothesized that clusters may differ in their treatment responses to CP.

Methods: We measured 20 cytokines, chemokines and cell adhesion markers using a multiplex technique at the time of inclusion in the CONFIDENT trial in patients of centers having accepted to participate in this secondary study.

View Article and Find Full Text PDF

Background: The distribution of anti-factor Xa activity (AXA) in patients with nonvalvular atrial fibrillation (NVAF) taking edoxaban 15 mg has not been fully elucidated.

Methods And Results: The trough and peak AXA were measured in 19 NVAF patients taking edoxaban 15 mg. We compared these results with those in patients taking edoxaban 30 mg.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!