OSP Manufacturer Salix Sued, Alleged Kidney Damage from OsmoPrep

Morrisville, NCThe US Food and Drug Administration (FDA) recently weighed in on oral sodium phosphates (OSP) and acute phosphate nephropathy after receiving more than 20 reports of kidney damage linked to the use of oral sodium phosphates.

In response, the manufacturer of Fleet Phospho-soda and Fleet Phospho-soda EZ-Pre-Bowel Cleansing System voluntarily withdrew the two products from the market in December 2008.

Salix Pharmaceuticals, another manufacturer of products used to cleanse the intestines in preparation for a colonoscopy, apparently decided to maintain the status quo instead. Salix added the FDA-mandated black box warnings to its OsmoPrep and Visicol products and performed a REMS evaluation, or Risk Evaluation and Mitigation Strategies, which are designed to determine which populations are at risk when using the product. The evaluation determined that the elderly, those who are dehydrated or have pre-existing kidney damage and those concurrently on other drugs are at the greatest risk for kidney damage, according to a recent issue of the Medical Letter on the CDC & FDA.

Having fulfilled FDA requirements with those additions, Salix allowed OsmoPrep and Visicol to remain on the market.

Now, Salix Pharmaceuticals Ltd. and Salix Pharmaceuticals Inc. of Morrisville, North Carolina, are listed as defendants in litigation filed on behalf of four plaintiffs who allege kidney damage due to use of OsmoPrep. Listed as an injury is acute phosphate nephropathy, for which the plaintiffs claim they require dialysis.

The action was filed on December 23, 2009, in Burke County, North Carolina.

Salix was also the focus of the Gastrointestinal Drugs Advisory Committee of the FDA on February 23 with regard to the safety and efficacy of the New Drug Application (NDA) for XIFAXAN (rifaximin) Tablets, 550 mg for the maintenance of remission of hepatic encephalopathy. Salix currently markets XIFAXAN®(rifaximin) tablets 200 mg.

On the morning of the planned FDA meeting, Salix announced that NASDAQ had stopped trading Salix common stock.