As Health Canada previously communicated , Alere Inc. is withdrawing the Alere INRatio ® and INRatio ® 2 Prothrombin Time (PT) Monitoring Systems (professional use and patient self-test) devices from the Canadian market. These devices measure blood clotting time in patients requiring warfarin and other oral blood-thinning medicines. There is a risk that the Alere devices provide an inaccurate low reading. This could result in an improper dosage of warfarin or other blood-thinning medications being administered, leading to excessive bleeding, which may result in serious health concerns that could potentially be fatal.