Rivaroxaban and other direct-acting oral anticoagulants (DOACs)

Increased risk of recurrent thrombotic events

United Kingdom. The MHRA has announced that a clinical trial has shown that there is an increased risk of recurrent thrombotic events associated with rivaroxaban (Xarelto®) use compared to warfarin, in patients with antiphospholipid syndrome and a history of thrombosis.

Direct-acting oral anticoagulants (DOACs) are indicated for the treatment and prevention of venous thromboembolism, and prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation with one or more risk factors. DOACs available are rivaroxaban, apixaban (Eliquis®), edoxaban (Lixiana®) and dabigatran (Pradaxa®).

A clinical trial compared rivaroxaban to warfarin in 120 patients and showed that use of rivaroxaban in patients with antiphospholipid syndrome could be associated with increased rates of recurrent thrombotic events compared to therapy with warfarin.

There have been no completed clinical trials for use of other DOACs such as apixaban, edoxaban and dabigatran in patients with antiphospholipid syndrome, therefore available data for these medicines are limited.

However, available data suggest that other DOACs may also be associated with a similarly increased risk of recurrent thrombotic events as with use of rivaroxaban.

Health-care professionals are advised to review whether continued treatment with a DOAC is appropriate for patients diagnosed with antiphospholipid syndrome and consider switching to a vitamin K antagonist such as warfarin.

Reference : Drug Safety Update, MHRA, 19 June 2019 (gov.uk/mhra)