Direct oral anticoagulant plasma levels in hospitalized COVID-19 patients treated with dexamethasone

Direct oral anticoagulants (DOACs) are not recommended in COVID-19 patients receiving dexamethasone because of potential drug-drug and drug-disease interactions affecting anticoagulant concentration and activity. To evaluate short- and long-term pharmacokinetic interactions, serial through and peak DOAC plasma levels were prospectively measured during and after dexamethasone therapy, as well as during the acute phase and after recovery from COVID-19 in hospitalized, non-critically ill patients undergoing treatment with DOACs. Thirty-three (18 males, mean age 79 years) consecutive patients received DOACs (17 apixaban, 12 rivaroxaban, 4 edoxaban) for atrial fibrillation (n = 22), venous thromboembolism (n = 10), and acute myocardial infarction (n = 1). Twenty-six patients also received dexamethasone at a dose of 6 mg once daily for a median of 14 days. Trough DOAC levels on dexamethasone were within and below expected reference ranges respectively in 87.5 and 8.3% of patients, with no statistically significant differences at 48–72 h and 14–21 days after dexamethasone discontinuation. Peak DOAC levels on dexamethasone were within expected reference ranges in 58.3% of patients, and below ranges in 33.3%, of whom over two thirds had low values also off dexamethasone. No significant differences in DOAC levels were found during hospitalization and after resolution of COVID-19. Overall, 28 patients were discharged alive, and none experienced thrombotic or bleeding events. In this study, dexamethasone administration or acute COVID-19 seemed not to affect DOAC levels in hospitalized, non-critically ill COVID-19 patients.