OSP Timeline

FDA research paper indicates link between OSP products and serious kidney damage, renal failure has been known for years

In a news release dated December 2008, the FDA alerted health care providers and consumers of a new black box warning for both prescription and over-the-counter (OTC) oral sodium phosphate (OSP) products. Prescription products are routinely prescribed to cleans the bowel before a colonoscopy and other medical procedures, while individuals sometimes use OTC products to cleanse the colon.

The alert warned of a link between OSP use and a type of serious kidney damage, called acute phosphate nephropathy.

The release mentions that as long ago as 2006 – two years prior to this alert – the FDA issued a Science Paper and a Healthcare Professional sheet describing the risks associated with the use of OSP products for bowel cleansing.

Since then, the FDA says, as part of its post-marketing surveillance, the agency has received reports of 20 unique cases of kidney injury associated with the use of OsmoPrep. Of the reported cases, three were biopsy-proven cases of acute phosphate nephropathy. The onset of kidney injury in these cases varied, occurring in some within several hours of use of these products and in other cases up to 21 days after use.

The FDA Science Background paper cites data collected even earlier, with studies conducted in 2003 revealing cases of acute phosphate nephropathy following the use of OSP products.

Read the FDA Science Background Paper.