The changing use of anticoagulants in New Zealand

To assess the change in the use of oral anticoagulants in New Zealand over 10 years since the introduction of dabigatran and rivaroxaban.

Data were collected from the National Pharmaceutical database from January 2011 to March 2021. Seven and a half million prescriptions for oral anticoagulants were analysed.

The total number of people taking oral anticoagulants increased from 46,000 in July 2011 to 105,000 by March 2021. The growth was predominantly from the increased use of direct oral anticoagulants (DOACs). Initially, dabigatran was the only funded DOAC in New Zealand; approximately 50,000 people were taking this medication by August 2018, when rivaroxaban was introduced. Subsequent growth has predominantly been from rivaroxaban, with 23,000 users by March 2021. Warfarin use has dropped by 50% over the last 10 years.

The introduction of the DOACs was expected to reduce the use of warfarin. However, the rapid rise in DOAC use was not predicted. The increase is most likely in patients with atrial fibrillation with the positive benefit of reducing the incidence of embolic stroke. However, having a high proportion of the elderly population (15% of people over 75-years) on anticoagulants has implications for the health sector, making hospital admissions and surgery more complex.