In July 2011, FDA began a pilot program to notify people of drug recalls before they are classified in an effort to expedite notifications of human drug product recalls to the public. FDA is now able to accomplish the goal of expedited notification within the Enforcement Report. These recalls are identified within the Enforcement Report by the label of “Not Yet Classified” in the “Classification” column. It is also possible to search the Enforcement Report for these “Not Yet Classified” recalls using the filter drop down menu. Therefore, as of September 15, 2017 FDA will discontinue the pilot program, and will no longer post drug recalls that are pending classification on this webpage. To see posted recalls that are pending classification go to the weekly Enforcement Report.
The terminal half-life of warfarin after a single dose is approximately 1 week; however, the effective half-life ranges from 20 to 60 hours, with a mean of about 40 hours. The clearance of R-warfarin is generally half that of S-warfarin, thus as the volumes of distribution are similar, the half-life of R-warfarin is longer than that of S-warfarin. The half-life of R-warfarin ranges from 37 to 89 hours, while that of S-warfarin ranges from 21 to 43 hours. Studies with radiolabeled drug have demonstrated that up to 92% of the orally administered dose is recovered in urine. Very little warfarin is excreted unchanged in urine. Urinary excretion is in the form of metabolites.