Therapeutic monitoring of unfractionated heparin - trials and tribulations.
Heparin is one of the oldest biological medicines with an established role in prevention and treatment of arterial and venous thromboembolism. Published therapeutic ranges for unfractionated heparin (UFH) mostly precede the large increase in the number of activated partial thromboplastin time (APTT) reagent/instrument combinations that now show wide variability. Areas covered: This paper explores the use of UFH, the development of heparin therapeutic ranges (HTRs), and the strengths and limitations of the methods used to monitor heparin's anticoagulant effect. Expert commentary: Despite longstanding use of UFH for management of thromboembolic conditions, the optimal test for monitoring UFH remains undetermined. Although used extensively for monitoring UFH, routine APTT-derived HTRs are based on limited science that may have little relevance to current laboratory practice. Anti-FXa levels may provide better and more reliable HTRs; however, even these levels show considerable inter-laboratory variation, and there are insufficient clinical studies proving improved clinical efficacy. Alternative tests for monitoring UFH reported over time have not been proven effective nor feasible, secondary to technical or cost issues, or lack of general adoption. Thus, despite limited evidence of clinical utility, an uncomfortable marriage of convenience represented by heparin laboratory monitoring is unlikely to be terminated in the immediate future.
['Baluwala|Israfil|I|', 'Favaloro|Emmanuel J|EJ|', 'Pasalic|Leonardo|L|']
D000925:Anticoagulants D002986:Clinical Trials as Topic D016903:Drug Monitoring D065427:Factor Xa Inhibitors D006493:Heparin D006495:Heparin, Low-Molecular-Weight D006801:Humans D010314:Partial Thromboplastin Time D013923:Thromboembolism D016896:Treatment Outcome D054556:Venous Thromboembolism
Unfractionated heparin therapeutic range activated partial thromboplastin time APTT anti-FXa assay low molecular weight heparin