Background
Apixaban, a non‐vitamin K oral anticoagulant (
NOAC
), was approved in Japan in 2012 for the prevention of thromboembolic events in patients with nonvalvular atrial fibrillation (
NVAF
). However, the safety and effectiveness of apixaban in clinical practice have not yet been elucidated thoroughly among Japanese
NVAF
patients.
Methods
A postmarketing surveillance study was conducted to determine the safety and effectiveness of apixaban. Patients were followed‐up for 104 weeks. Outcome events included adverse drug reactions (
ADR
s), hemorrhages, and thromboembolic events (ischemic stroke, systemic embolism [
SE
], and transient ischemic attack [
TIA
]).
Results
Among 6306
NVAF
patients in the safety analysis set (age, 74.5 ± 10.1 years; women, 41.1%; and
CHADS
2
score, 2.0 ± 1.4), 3600 patients (57.1%) received the standard dose (5 mg twice daily) and 2694 (42.7%) received a reduced dose (2.5 mg twice daily) of apixaban.
ADR
s occurred in 604 patients (9.58%), with the most common being epistaxis (0.86%), subcutaneous hemorrhage (0.67%), and hematuria (0.57%). Incidence rate of any hemorrhages and major hemorrhage was 5.52% per year and 2.36% per year, respectively. Incidence rate of ischemic stroke/
SE
/
TIA
was 1.00% per year among 6286 patients in the effectiveness analysis set. Among three subgroups (3106 apixaban initiators, 2038 patients switched from warfarin, and 1118 patients switched from other
NOAC
s), incidence rates of major hemorrhage (
P
= 0.221 for trend) and ischemic stroke/
SE
/
TIA
(
P
= 0.686 for trend) were comparable.
Conclusions
No new safety signals of apixaban were identified in Japanese
NVAF
patients. Safety and effectiveness of apixaban were consistent with those in the
ARISTOTLE
study.