Health Canada Removes Bowel Cleansing Indication for OTC OSPs

Ottawa, ONConcerns over oral sodium phosphate (OSP) continue, with the latest salvo in the OSP debate coming from Health Canada. Earlier this month the Canadian health agency declared that oral phosphate soda is no longer indicated for purgative use (bowel cleansing) due to a risk for OSP kidney damage, while stressing oral sodium phosphate products in general remain safe for use as a laxative.

Bowel cleansing is a process that happens prior to a colonoscopy. Back in March Health Canada, akin to the US Food and Drug Administration (FDA) issued a public health warning due to a concern that OSP products could potentially cause serious adverse effects, including electrolyte disturbances and kidney damage.

In Canada, according to an August 5th report from Marketwire, two of three OSP products remain on the market with updated labels removing the indication for bowel cleansing.

The third product—Fleet Phospho-Soda Oral Laxative, has been voluntarily pulled from the Canadian market by Johnson & Johnson MERCK Consumer Pharmaceuticals.

Meanwhile, a lawyer in Texas who also practiced as an internist and cardiologist prior to moving into law writes that there are those who are more susceptible to renal failure than others, within the context of taking an OSP. Dr. Shezad Malik writes on the Dallas Fort Worth Injury Lawyer blog that some factors that can affect patients in this way include "having pre-existing kidney damage, being dehydrated while taking the OSP, being on an angiotensin-converting enzyme (ACE) inhibitor while taking the OSP, being on an angiotensin receptor blocker (ARB) while taking the OSP, having increased bowel transit times (such as a bowel obstruction or colitis), or being on a non-steroidal anti-inflammatory drug (NSAID) while taking the OSP."

A final risk factor, Dr. Malik notes, "is being 55 years of age or older at the time the OSP is taken."

It was in December of last year when the FDA issued its warning with regard to OSP and mandated black box warnings for the risk of acute phosphate nephropathy. However, according to Dr. Malik there were earlier studies linking oral sodium phosphates to kidney damage. A joint task force of the American Society of Colon and Rectal Surgeons, the American Society for Gastrointenstinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons issued a consensus statement with regard to the issue in 2006, together with an FDA alert in March of that year.

And while other manufacturers have complied with the black box warning, CB Fleet recalled Fleet Phospho-soda and Fleet Phospho-soda EZ-Prep Bowel Cleansing System from the market altogether.