Background Oral anticoagulants are established drugs of choice for the prevention and treatment of thromboembolic events. However, monitoring their safety remains warranted. Objective The aim was to analyze spontaneous reports of adverse drug reactions related to oral anticoagulants in the Czech Republic. Setting Retrospective observational pharmacovigilance study. Methods Adverse drug reaction reports were obtained from the State Institute for Drug Control between January 2005 and November 2017. Reports related to warfarin, dabigatran, apixaban, and rivaroxaban received from healthcare professionals and patients were analyzed. Main outcome measure Frequency and nature of adverse drug reactions reported to oral anticoagulants. Results In total, 297 reports containing 672 adverse drug reactions were received; 269 reports were sent by healthcare professionals (85% by physicians). In 65% of all reports, reactions were due to direct oral anticoagulants. A higher total number of adverse drug reactions was associated with direct oral anticoagulants than with warfarin [reporting odds ratio (ROR): 10.76; confidence interval (CI): 8.70-13.32; p < 0.001]. Along with the increasing utilization of direct oral anticoagulants, the reporting rate gradually declined over time, especially for rivaroxaban and apixaban. Fatal outcomes were reported in 7%, mostly for dabigatran. Hemorrhagic reactions were the most frequently reported adverse drug reactions (37% associated with dabigatran, 28% with apixaban, 24% with warfarin, and 23% with rivaroxaban), and compared to warfarin, they were significantly more often associated with direct oral anticoagulants (ROR: 14.36; CI: 9.57-21.54; p < 0.001). Conclusion The number of adverse drug reaction reports related to oral anticoagulants in the Czech Republic was relatively low, compared to other studies, but 96% of the cases were serious. Data from spontaneous adverse drug reactions reporting should be further analyzed in order to obtain additional information on the safety profile of oral anticoagulants.

Centre for Pharmaceutical Research Research Group Clinical Pharmacology and Clinical Pharmacy Vrije Universiteit Brussel Brussels Belgium

Department of Pharmacovigilance State Institute for Drug Control Prague Czech Republic

Department of Social and Clinical Pharmacy Faculty of Pharmacy in Hradec Kralove Charles University Hradec Kralove Czech Republic

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