Differences in the location of bleeding with direct oral anticoagulants vs. vitamin K antagonists: A study in the World Health Organization's pharmacovigilance database

AimsClinical trials have found differences in bleeding locations between direct oral anticoagulants (DOAC) and vitamin K antagonists (VKA). The present study was performed to investigate these differences in real life using reports of adverse drug reactions registered in the World Health Organization's pharmacovigilance database, VigiBase (R). MethodsAll bleeding registered between 1 January 2008 and 31 December 2021 in adults were included. The main objective was to compare bleeding locations reported with DOAC with those with VKA. As a secondary objective, we performed the same comparison with Xa vs. thrombin inhibitors. Results were presented as reporting odds ratios (RORs) adjusted on age, gender, origin of reports and co-medications with their 95% confidence interval. ResultsDuring this 14-year period, 142 228 instances of bleeding were registered with oral anticoagulants, including 39 570 with VKA and 102 658 with DOAC. Mean time to event was lower with DOAC (7.6 months) than with VKA (29.9 months) (P < .001). Significant differences in bleeding locations were found in the reports with less cerebral, urologic and nasal bleeding, more gynaecologic bleeding with DOAC than with VKA, without any significant differences in digestive and cutaneous locations. A higher risk of bleeding reports was found with Xa inhibitors vs. dabigatran whatever the locations (except digestive bleeding). ConclusionThis real-life study shows that the differences in bleeding locations between DOAC and VKA are not limited to the brain or gastrointestinal tracts. Significant differences were also found between Xa and thrombin inhibitors.