Companies are required under 21 CFR 314.81(b)(3)(iii) to provide FDA with a six month advance notice of the discontinuation of sole source products that are life-supporting, life-sustaining or for use in the prevention of a debilitating disease or condition. From time to time, FDA also receives notification for other products. These discontinuations are provided below for informational purposes only.
http://www.fda.gov/Drugs/DrugSafety/DrugShortages/ucm050794.htm
