Kidney Risk Spurs Warning on Bowel Cleansers

The Food and Drug Administration (FDA) has acted to reduce the risk of acute kidney injury from oral sodium phosphate (OSP) products. These products are routinely used as bowel cleansers before colon examinations and other medical procedures.

The agency is adding a Boxed Warning to two prescription OSP products: Visicol and OsmoPrep. The warning addresses the risk of a kidney injury known as acute phosphate nephropathy.

FDA has also directed the makers of Visicol and OsmoPrep to

• develop a risk evaluation and mitigation strategy
• distribute a Medication Guide to alert patients to the risk of kidney injury
• conduct a postmarketing clinical trial to further assess this risk

Concerns With OTC Products Too

FDA is equally concerned about the risks associated with over-the-counter (OTC) OSP products (e.g., Fleet Phospho-soda) when they are used at higher doses for bowel cleansing.

The available data show no risk of acute kidney injury when OTC products are used at the lower doses as laxatives. But these products present the same risks as prescription OSP products when used for bowel cleansing.

FDA is recommending that consumers not use OTC OSP products for bowel cleansing. The agency plans to amend the labeling conditions for these products.

Safety Advice

OSP products should NOT be used

• by children under 18 years of age
• in combination with other laxative products containing sodium phosphate

OSP prescription products should be used with caution by people who are

• over 55 years of age
• suffering from dehydration, kidney disease, acute colitis, or delayed bowel emptying
• taking certain medicines that affect kidney function, including
  — diuretics (fluid pills)
  — angiotensin converting enzyme inhibitors (medications that lower blood pressure)
  — angiotensin receptor blockers (treatments for high blood pressure and heart or kidney failure)
  — possibly nonsteroidal anti-inflammatory drugs (similar to ibuprofen and other arthritis medications)

Serious side effects or quality problems associated with these products can be reported to FDA's MedWatch Adverse Event Reporting program.

This article appears on FDA's Consumer Updates page, which features the latest on all FDA-regulated products.

Date Posted: December 16, 2008

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