Title:Oral Factor Xa (FXa) Inhibitors for Treatment of Heparin-induced Thrombocytopenia (HIT)
VOLUME: 16
Author(s):Nicholas Munafo*, Sagar Patel, Kristine C. Willett and Amanda Morrill
Affiliation:Department of Pharmacy Practice, MCPHS University School of Pharmacy Worcester/Manchester 2 Winship Place, Brighton MA, 20125,, Department of Pharmacy Practice, MCPHS University School of Pharmacy– Worcester/Manchester Sanofi Genzyme, Cambridge, MA,, Department of Pharmacy Practice MCPHS University, School of Pharmacy – Worcester/Manchester,, Department of Pharmacy Practice MCPHS University, School of Pharmacy – Worcester/Manchester
Keywords:anticoagulant, heparin induced thrombocytopenia, HIT, DOAC, factor Xa, apixaban, rivaroxabananticoagulant, heparin induced thrombocytopenia, HIT, DOAC, factor Xa, apixaban, rivaroxaban
Abstract:Background: Heparin is the most commonly used injectable anticoagulant for many indications, ranging from
the treatment of atrial fibrillation to prevention of clotting in patients undergoing surgery. Currently only argatroban and
bivalirudin are FDA approved for the management of heparin induced thrombocytopenia (HIT) in the United States, both
of which are direct thrombin inhibitors. The agents being reviewed, apixaban and rivaroxaban, are oral direct factor Xa
(FXa) inhibitors. Currently, neither has FDA approval for use in HIT. The objective of this review is to summarize the
current evidence available regarding the use of oral factor Xa inhibitors for the treatment of HIT.
Methods: A literature search was conducted using Medline and Ovid Embase. Search terms included heparin induced
thrombocytopenia, HIT, apixaban, rivaroxaban, Xa Inhibitor, direct thrombin inhibitor, NOAC, and DOAC. Studies and
case reports were included if they evaluated the efficacy and safety of oral FXa inhibitors for the treatment of HIT.
Additional literature and case reports were found through bibliographic review.
Results and discussion: Currently, available literature includes an in vitro study with apixaban, case reports, and
retrospective and prospective cohort studies. The in vitro study evaluated the interaction between apixaban and platelets in
the presence of HIT antibodies, which assessed its potential for use in HIT management. Fourteen case reports and one
case series were also identified, of which six described treatment with apixaban and eight with rivaroxaban. Lastly, there
were also four cohort studies published evaluating the use of direct acting oral anticoagulants (DOACs), including oral
factor Xa inhibitors in patients with HIT. Although there are no published randomized control trials evaluating the use of
FXa inhibitors in the management of HIT, there are several findings that may guide clinicians on the use of these agents in
practice.
Conclusion: As indicated by the case reports, case series and cohort studies detailing clinical use and described in this
manuscript, there are data, and positive patient outcomes that support the potential use of these agents for HIT, and are an
impetus for future studies.
