Impacts of Common Anticoagulants on Coagulation Testing

^aArgatroban, bivalirudin (Angiomax), and dabigatran (Pradaxa). Only dabigatran is a DOAC; argatroban and bivalirudin are administered parenterally.

^bRivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa).

^cReagent contains heparin neutralizer; effect may occur with supratherapeutic drug levels.

^dDrug, concentration, and reagent dependent.

^eFor accurate drug quantitation, the selected assay must correspond with the specific drug (ie, UFH, LMWH, direct factor Xa inhibitor) that the patient is receiving. Additionally, reported concentrations will be inaccurate (ie, overestimated) when >1 drug with anti-Xa activity is present (eg, when a patient is being bridged between medications).

^fDrug does not interfere with assay, but presence may affect analyte.

^gThis table indicates the possible effects on LA assays in the absence of anticoagulant neutralizing reagents (such as heparinase, polybrene, or activated charcoal-based DOAC neutralizers). LA assays may also show anticoagulant interference if drug levels exceed the capacity of the neutralizing reagent used by the laboratory.

^hPresence of UFH, LMWH, direct thrombin inhibitors, and direct Xa inhibitors may produce inhibitory patterns and may prevent accurate quantitation (underestimation) of factor activity. May also interfere with and cause false-positive Bethesda assays (false-positive coagulation factor inhibitor). Chromogenic factor XIII activity may also be falsely decreased in the presence of direct thrombin inhibitors. Factor XIII assays are not affected by other anticoagulants.

ⁱaPTT-based factor assays (factors VIII, IX, XI, XII) are more likely to demonstrate assay interference and underestimation than PT-based factor assays (factors II, V, VII, X). The effect is more pronounced with UFH than with LMWH.

APC, activated protein C; aPTT, activated partial thromboplastin time; dRVVT, dilute Russell viper venom time; INR, international normalized ratio; LA, lupus anticoagulant; PT, prothrombin time; tPA, tissue plasminogen activator

Sources: Linkins, 2002 ; Molinaro, 2008 ; Genzen, 2005 ; Hillarp, 2011 ; Adcock, 2015 ; Dale, 2014 ; Tsutsumi, 2015 ; Favaloro, 2019 ; Gosselin, 2018