High rates of off-label doses seen in ED patients receiving DOACs

Vitamin K antagonists (VKAs) are the most commonly used direct oral anticoagulant (DOAC), followed by rivaroxaban and apixaban, in the emergency department (ED), with a significant number of patients being prescribed off-label doses, according to a recent study.

“While no difference was found for the respective anticoagulants with respect to bleeding, concomitant aspirin use was a significant predictor for bleeding in our collective,” the investigators said.

This retrospective analysis included patients presenting to the ED between 1 January and 31 December 2018, with therapeutic DOAC (ie, VKA, rivaroxaban, apixaban, edoxaban, and dabigatran). The authors carried out a detailed chart review for each patient concerning characteristics, indication, and bleeding complications.

In total, 19,662 consecutive cases in the emergency department were reported, of which 1,721 (9 percent) were treated with DOAC. The most widely used anticoagulants were VKA (41 percent), rivaroxaban (36 percent), and apixaban (19 percent), while the most common indications were stroke prophylaxis in patients with atrial fibrillation (63.2 percent) and venous thromboembolism (24.1 percent).

No indication was identified in 27 patients (1.6 percent). Moreover, 32 percent were classified to have either off-label doses of OACs or an international normalized ratio out of range (in VKA). However, 20 percent were classified as off-label underdosed and 12 percent as overdosed.

There was no difference seen in the likelihood of bleeding on admission between the respective drugs. Concomitant use of aspirin was the only factor that correlated significantly with the presence and higher severity of bleeding.