ABSTRACT
Background : Dexamethasone is part of the standard treatment of COVID-19 patients who need oxygen support. COVID-19 patients have a high risk of venous and arterial thrombosis, therefore adequate anticoagulation is of vital importance. Direct oral anticoagulants (DOACs) are generally not recommended in patients with dexamethasone due to possible drug-drug interactions which may decrease DOACs plasma levels. Therefore, data on the interaction between dexamethasone and DOACs is urgently needed. Aims : To assess DOAC plasma levels in patients with simoultaneous use of dexamethasone. Methods : Trough and peak DOAC plasma levels, by means of antiactivated factor X (anti-Xa) were prospectively collected in hospitalized COVID-19 patients treated with dexamethasone and DOACs (apixaban, rivaroxaban and edoxaban) and in hospitalized COVID-19 patients treated with DOACs only, to assess whether these values were within reference range. Results : Data were collected across two centres in Italy and the Netherlands. A total of 20 patients, 16 with DOACs and dexamethasone and 4 with DOACs only were enrolled. Twelve patients were on anticoagulant treatment for atrial fibrillation, seven for venous thromboembolism, and one for myocardial infarction. In 15 patients DOACs were started during the hospitalization. None of the patients had trough DOAC plasma levels below reference range. Only one patient (6.3%) treated with rivaroxaban had peak levels below reference range. Six patients (37.5%) in the dexamethasone group and two control patients (50%) had peak or trough DOAC plasma levels above reference range. Conclusions : In COVID-19 patients, the effect of dexamethasone use on DOAC plasma levels seems limited. This suggests that DOACs can be safely started or continued in COVID-19 patients treated with dexamethasone.