Alere Inc. has initiated a voluntary withdrawal of the Alere INRatio and INRatio2 PT/INR anticoagulation monitoring systems from the U.S. market. The devices determine the international normalized ratio (INR) in samples of capillary whole blood.
Alere is working with the FDA to determine the most appropriate timing for product discontinuation and will provide guidance on transitioning patients to an alternate solution.
In December 2014, the company issued an “urgent correction” notice stating that the two devices, under certain circumstances, could display an INR that is lower than that obtained through a laboratory method. This problem could arise with blood samples from patients with any anemia accompanied by a hematocrit of less than 30%; any condition associated with elevated fibrinogen levels; or any bleeding or unusual bruising, the company said.
During the past two years, Alere worked to develop software modifications that would address the systems’ potential to deliver results that differed from lab measurements. These enhancements were submitted to the FDA at the end of 2015.
The agency notified Alere that the company’s studies did not adequately demonstrate the effectiveness of the software modifications. The FDA advised Alere to submit a proposed plan to voluntarily remove the INRatio devices from the market.