In December 2008 the FDA issued a warning to consumers about acute phosphate nephropathy, a type of kidney failure caused by medication. The medication is associated with oral sodium phosphate products (OSP) for bowel cleansing prior to colonoscopy or other procedures.
These products include the medications, Visicol and OsmoPrep, and OSP’s available over-the-counter without a prescription as laxatives (e.g., Fleet Phospho-soda). In some cases when used for bowel cleansing, these serious adverse events have occurred in patients without identifiable factors that would put them at risk for developing kidney failure caused by medication.
According to the U.S. Food and Drug Administration (FDA), “[a]cute phosphate nephropathy is a form of acute kidney injury that is associated with deposits of calcium-phosphate crystals in the renal tubules that may result in permanent renal function impairment. Acute phosphate nephropathy is a rare, serious adverse event that has been associated with the use of OSPs. The occurrence of these events was previously described in an Information for Healthcare Professionals sheet and an FDA Science Paper issued in May 2006. Additional cases of acute phosphate nephropathy have been reported to FDA and described in the literature since these were issued.”
Both the Visicol and OsmoPrep laxatives are a prescription only medication, and as stated, used to clean out the intestines before a colonoscopy. The medication active ingredient sodium phosphate (the phosphate in acute phosphate nephropathy), acts as a laxative by drawing large amounts of water into the colon. The result of water in the colon is watery bowel movements. This cleans out the intestines so that your doctor can clearly view them during your colonoscopy.
The FDA was aware of colonoscopy related kidney failure as early as 2006, yet they still chose to license the product OsmoPrep. And as a result in 2008, due to the number of kidney failure reports, the FDA required the manufacturer of Visicol and OsmoPrep, the two OSP’s available by prescription only, to add a Boxed Warning about colonoscopy related kidney failure.
FDA also required that the manufacturer develop and implement a risk evaluation and mitigation strategy (REMS), which will include a Medication Guide, to ensure that the benefits of these products outweigh the risk of acute phosphate nephropathy, and to conduct a postmarketing clinical trial to further assess the risk of acute kidney injury with use of these products.
FDA acknowledged that OSP products, in addition to use for bowel preparation, have a long history of safe use as non-prescription products as laxatives (i.e. for relief of constipation) and accordingly, they will continue to be available over-the-counter for this use.
However, in light of the risk of acute phosphate nephropathy, over-the-counter laxative OSP products should not be used for bowel cleansing. Consumers should only use OSPs for bowel cleansing pursuant to a prescription from a healthcare professional.
According to the statement issued by the FDA in 2008, they intended “to amend the labeling conditions for OSP products available in the OTC setting to address this concern with bowel cleansing use and to improve the safe use of OSPs that are available over-the counter. FDA’s amendment to remove the professional labeling for bowel cleansing for these OSPs available over-the-counter will be published in a future Federal Register notice.”
Osmoprep lawsuits are being filed nationwide for kidney damage.