Warfarin vs Rivaroxaban – NPS RADAR weighs up the evidence
The latest edition of NPS RADAR reviews the new oral anticoagulant rivaroxaban, and concludes that there is no evidence that people with non-valvular atrial fibrillation (NVAF) who are well controlled on warfarin will benefit clinically from a switch to rivaroxaban.
Rivaroxaban is one of several new oral anticoagulants now available as an alternative to warfarin. Although approved by the Therapeutic Goods Administration for use in stroke prevention in NVAF, it is not PBS listed for this indication and is currently only available on private prescription for stroke prevention in atrial fibrillation (AF).
A pivotal clinical trial, the ROCKET-AF study, found that rivaroxaban 20 mg once daily is no worse than warfarin for reducing the incidence of stroke in people with NVAF. Rivaroxaban showed a significantly lower incidence of intracranial bleeding but significantly more gastrointestinal bleeds.
NPS MedicineWise clinical adviser Dr Philippa Binns says that on weighing up the evidence, it was found that people with NVAF who are well controlled on warfarin will not benefit clinically from switching to rivaroxaban.
“If a patient is able to tolerate warfarin then keeping them at their optimal warfarin dose with regular monitoring is the best way to prevent a stroke,” says Dr Binns.
“If people at risk of stroke are not able to maintain a therapeutic INR (International Normalised Ratio) on warfarin because of food or drug interactions, or regular monitoring of INR is difficult or impractical, rivaroxaban may be an alternative.”
There is a lack of long term safety data for rivaroxaban and its safety has not been demonstrated in people at high risk of bleeding. It should therefore be avoided in people who have, or are at risk of, active bleeding, such as those with intracranial or gastrointestinal bleeding. It should also be avoided in people with significant hepatic disease or renal impairment.
“Bleeding is the greatest safety concern with all anticoagulants, including warfarin and rivaroxaban, but unlike warfarin, there is currently no valid test for measuring coagulation levels in people taking rivaroxaban and no valid antidote to its effects,” says Dr Binns.
“Like all new medicines, the full range of side effects of rivaroxaban is not yet known, so it should be used with caution.”
This edition of RADAR also includes an in depth review of rasagiline (Azilect) for Parkinson’s disease and pregabalin (Lyrica) for neuropathic pain (available only online), as well as In Brief articles on the following medicines and PBS listing changes:
· Quadrivalent human papillomavirus vaccine (Gardasil) available for boys
· Riavaroxaban (Xarelto) PBS listed for deep vein thrombosis
To read the full reviews go to www.nps.org.au/radar.
NPS RADAR is a timely, independent publication for health professionals published by NPS MedicineWise. It provides the latest evidence-based assessments of new drugs, research, and PBS listings.
To learn how to evaluate the evidence, the free NPS online learning program Finding Evidence – Recognising Hype teaches critical appraisal and other skills.
Independent, evidence-based and not-for-profit, NPS MedicineWise enables better decisions about medicines and medical tests. We are funded by the Australian Government Department of Health and Ageing.