Abstract
Oral vitamin K anticoagulation (warfarin, Coumadin, coumarin) has long been used for
long-term treatment and prophylaxis in a variety of clinical settings. Given the unpredictable
pharmacokinetic and food impact of warfarin, episodic monitoring is required. Since
the early 2000s, direct oral anticoagulants (DOACs) entered into clinical trials as
a potential alternative strategy to oral vitamin K antagonists for long-term anticoagulation.
As these drugs have predictable pharmacokinetics and pharmacodynamics, there was no
requirement for episodic or routine monitoring. However, shortly after their introduction
into clinical use, it became apparent that certain emergent or acute situations may
require some capacity to measure these drugs, especially in a bleeding patient with
DOAC exposure. The scramble for literature and data to support or suggest laboratory
methods which can rapidly and accurately quantify or estimate DOAC concentration soon
began. This review describes the literature to date, and recommendations for laboratories
to provide tests that will assure either the presence/absence of DOAC or the capacity
to quantify DOAC using rapid methods that could be implemented on most clinical laboratory
instruments.
Keywords
apixaban - dabigatran - edoxaban - rivaroxaban - prothrombin time - activated partial
thromboplastin time - dilute thrombin time - Ecarin - anti-Xa
