December 11, 2008

FDA orders bowel cleanser safety warnings

The U.S. Food and Drug Administration says it will add a Boxed Warning to prescription oral sodium phosphate products Visicol and OsmoPrep.

The FDA said the action is being taken to warn consumers about the risk of acute phosphate nephropathy -- a type of serious kidney injury. Patients routinely take sodium phosphate products to cleanse their bowels before a colonoscopy or other medical procedures.

The FDA also voiced concern about risks associated with the use of similar over-the-count products, such as Fleet Phospho-soda, when they are used at higher doses for bowel cleansing. But officials said data does not indicate a risk of kidney injury when those OTC products are used at lower doses for laxative use.

Though rare, (there are) serious adverse events associated with the use of oral sodium phosphates -- both prescription and over-the-counter products, said Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research. "In some cases, these serious adverse events occurred in patients with no pre-existing health factors that would have put them at risk for developing kidney injury.

We cannot rule out, however, that some of these patients were dehydrated prior to ingestion of OSP products or they did not drink sufficient fluids after ingesting OSP products, Woodcock added.