Management of direct oral anticoagulant drug interactions in hospitalized patients

Moderate-strong CYP3A4 or Pgp inhibitors and inducers alter direct oral anticoagulant (DOAC) pharmacokinetics. Whether the presence of a DOAC drug-drug interaction (DDI) prompts in- hospital changes in management remains unknown. We identified all hospitalized patients at our institution who were admitted with a clinically relevant DOAC DDI from 01/2021 to 06/2021. Clinically relevant DOAC DDIs were defined as those listed in the prescribing information or FDA CYP3A4/Pgp inhibitors clinical indexes. We assessed the prevalence of DOAC DDIs and categorized their management as: drug stopped, drug held, or drug continued. For drugs that were continued we assessed whether the dose of the DOAC or interacting drug was increased, decreased or unchanged during the admission. We ascertained the number of DOAC DDIs that prompted an automated prescribing alert in our electronic health record (EHR). Finally, we conducted a logistic regression model to compare users of DOACs with DDI who had their regimen adjusted versus those without adjustments, focusing on outcomes of rehospitalization and death, adjusting for age and gender. Among 3,725 hospitalizations with a DOAC admission order, 197 (5%) had a clinically relevant DOAC DDI. The DOAC and the interacting drug were continued at discharge for 124 (63%) hospitalizations. The most frequent adjustments were stopping the interacting drug (73%) and stopping the DOAC (15%). Only 7 (4%) of DOAC DDIs prompted an EHR alert. The adjusted odds ratios for rehospitalizations and death, respectively, among patients whose regimens were adjusted compared to those whose were not, were 1.29 (95% CI, 0.67 to 2.48; P = 0.44) and 1.88 (95% CI, 0.91 to 3.89; P = 0.09). Clinically relevant DDIs with DOACs occur infrequently among hospitalized patients and usually are managed without stopping the DOAC. The clinical impact of such DDIs and subsequent adjustments on thrombotic and hemorrhagic outcomes requires further investigation.