Salix Pharmaceuticals sued over alleged kidney damage due to OsmoPrep

Suits were commenced Dec. 23, 2009 in North Carolina for four users who allege kidney damage due to the use of OsmoPrep, a prescription drug used to cleanse the intestines in preparation for a colonoscopy. (Holshouser et al v. Salix Pharmaceuticals, Ltd. and Salix Pharmaceuticals. Inc.)

The actions are against two Morrisville, N.C., pharmaceutical companies, Salix Pharmaceuticals, Ltd., and Salix Pharmaceuticals, Inc. ( SLXP). The company, which specializes in marketing gastrointestinal drugs, began selling OsmoPrep in 2006. It had over $30 million in sales in 2008.

OsmoPrep contains two types of sodium phosphates, which work by drawing water in the bowels. A large number of pills are taken the day before and the day of the colonoscopy. Salix also sells a product, Visicol, with similar chemicals and has the same purpose.

In December 2008, after receiving a number of reports of kidney injury, the FDA required Salix to place a black box warning on the product, as to serious kidney damage occurring after use of OsmoPrep and also Visicol. A black box warning is the most strict type of warning that the FDA can force a drug supplier to use in its labeling.

Also as a condition for continuing to market OsmoPrep, the FDA required Salix to perform what is known as a REMS evaluation--Risk Evaluation and Mitigation Strategies. These are designed to determine which population is more at risk in using the product, such as older person, those who are dehydrated or have pre-existing kidney damage, and those concurrently on other drugs.

The liquid form of these oral phosphates had been used in Fleet Phospho-Soda, an over-the-counter product manufactured by C. B. Fleet in Virginia. Fleet withdrew this product from the market in December 2008 in response to a similar request from the FDA to enhance its warnings.

The four plaintiffs in this suit, which was filed in Burke County, N.C., sustained a variety of serious kidney injuries, including the need for dialysis. The medical name for the condition they have suffered is acute phosphate nephropathy.

The complaint alleged that Salix was aware of the risks of serious kidney damage at the time of first marketing OsmoPrep and up until the FDA forced the black box warning. Such information came from articles in the medical literature and individual case reports.

The suit was commenced by the Greensboro, N.C., firm of WardBlackLaw, with assistance of the firm of Rheingold, Valet, Rheingold, Shkolnik and McCartney LLP, of New York City. The Rheingold firm is also involved with the Fleet Phospho-Soda litigation which has been consolidated in Cleveland, OH.