Severe kidney injury linked to use of OSP products
On December 11, 2008, the Food and Drug Administration (FDA) issued a safety alert calling for a black box warning on prescription oral sodium phosphate (OSP) products used to prepare the bowel prior to colonoscopies following reports of a serious form of kidney injury in patients who had taken OSP products.
The black box warning fell on Salix  Pharmaceuticals’ prescription OSP brands Visicol and Osmo Prep, and serious warning was placed on over-the-counter OSP products such as Fleet Phospho-soda and Fleet Accu-Prep. The serious adverse event that was occurring in patients repeatedly over the years was a serious form of kidney injury now known as acute phosphate nephropathy.