March 20, 2006

The maker of Visicol, a drug used to prepare people for colonoscopies, says that Public Citizen's recent report about a study linking some precolonoscopy drugs to kidney failure does not put the study results in proper context.

In a recent notice, Public Citizen cited a study in the Journal of the American Society of Nephrology that says bowel-cleansing drugs containing sodium phosphate are an "underrecognized" cause of chronic kidney failure in the U.S.

Public Citizen singled out Salix Pharmaceuticals' prescription oral tablet Visicol (sodium phosphate, dibasic, anhydrous/sodium phosphate, monobasic, monohydrate), as well as the nonprescription product Fleet Phospho-Soda, made by C.B. Fleet.

Doug Bettenhausen, executive director of medical affairs at Salix, told FDAnews that Public Citizen did not clarify that out of the 21 cases of kidney failure, only one was attributable to Visicol while the other 20 were attributable to Fleet Phospho-Soda.

Bettenhausen also noted the patient on Visicol "was not an ideal patient for treatment" because he suffered from renal dysfunction and was taking an ACE inhibitor, which places people at higher risk for dehydration. Relevant warnings were clearly stated in the package insert, he added.

"Those patients have to be very carefully maintained on any drugs," Bettenhausen said regarding the patient on Visicol. "What appears to have happened was that he wasn't properly hydrated," he said.

Salix is awaiting the FDA's decision on a new drug application submitted last year for its Visicol follow-on, INKP-102. Salix acquired INKP-102 and Visicol when it merged with InKine Pharmaceutical late last year.

C.B. Fleet did not respond by FDAnews press time.