Bowel-Cleansers Getting Black Box Warning

The bowel-cleansing drugs Visicol and OsmoPrep will soon receive the FDA’s strongest warnings, a black box, on their labels. Visicol and OsmoPrep are prescription oral phosphate products, used by patients before colonoscopies. According to the FDA, there have been over 20 reports of serious kidney failure among patients using these drugs. Both Visicol and OsmoPrep are made by Salix Pharmaceuticals. The new warning urges caution for patients over 55, those who suffer from dehydration and kidney disease, and those taking medication that affects their kidneys. The FDA’s office of nonprescription products also voiced concern about over-the-counter phosphate products, which have been linked to serious kidney injury. Lethargy, drowsiness and swelling are some symptoms of kidney damage. Many of the over-the-counter phosphate products are only labeled for treating constipation, not for clearing the colon, though some people use them for that purpose. The FDA plans to update labels on many OTC phosphate drugs, though they can’t receive black box warnings like prescription drugs.