High fluctuation seen in anticoagulants use, off-label dosing stable

A recent study has found an increasing number of existing oral anticoagulation regimes being changed to apixaban, but the proportion of off-label dosages of all oral anticoagulants remains stable.

In addition, no difference is seen in bleeding rates, de novo strokes, or thromboembolisms between anticoagulants, as well as between correct and off-label doses.

“Recently published studies indicated a high proportion of patients taking direct oral anticoagulants are off-label under- or overdosed,” the investigators said.

This retrospective cohort study sought whether off-label dosages were corrected over time and whether off-label doses were associated with differences in bleeding rates, ischaemic stroke, or venous thromboembolism.

Patients who presented to the emergency department between 1 January and 31 December 2018, with therapeutic oral anticoagulation (ie, vitamin K antagonists [VKA], rivaroxaban, apixaban, edoxaban, and dabigatran), were included and followed for a maximum of 2 years until 31 December 2019.

The investigators then performed detailed chart reviews for each case concerning characteristics, indication, bleeding complications, or changes in the used substance or dosage.

A total of 2,588 consultations of 1,228 patients on therapeutic oral anticoagulation were reviewed. VKA and rivaroxaban lost the largest proportions of users in favour of apixaban during the maximum follow-up of 2 years. Meanwhile, the overall distribution of dosage correctness remained almost unimproved (correct dosing in 62.5 percent, underdosing in 23.6 percent, and overdosing in 13.9 percent).

No differences were seen in the corresponding outcomes with respect to bleeding events, ischaemic stroke, or venous thromboembolism among various anticoagulants, as well as between correct and off-label doses.