FDA Issues Safety Warning for Sodium Phosphate for Constipation

Megan Brooks


January 08, 2014

The US Food and Drug Administration (FDA) is warning about possible harm from exceeding the recommended dose of over-the-counter (OTC) sodium phosphate products to treat constipation.

In a statement posted online today, the agency said using more than 1 dose in 24 hours can cause rare but serious harm to the kidneys and heart, and even death.

The FDA said it has become aware of reports of severe dehydration and changes in serum electrolyte levels from taking more than the recommended dose of OTC sodium phosphate products, resulting in serious adverse effects on organs, such as the kidneys and heart, and in some cases resulting in death.

"The predominant electrolyte disturbances were hyperphosphatemia, hypocalcemia, and hypernatremia," the FDA said.

The problem surfaced in a review of the agency's Adverse Event Reporting System database and the medical literature, which turned up 54 cases in 25 adults and 29 children of serious adverse events associated with the oral or rectal use of OTC sodium phosphate drug products used to treat constipation, the FDA said.

"According to the reports, most cases of serious harm occurred with a single dose of sodium phosphate that was larger than recommended or with more than 1 dose in a day," the FDA said.

Use With Caution

Individuals who may be at higher risk for potential adverse events when the recommended dose of OTC sodium phosphate is exceeded include young children; individuals older than 55 years; patients who are dehydrated; patients with kidney disease, bowel obstruction, or inflammation of the bowel; and patients who are using medications that may affect kidney function.

These medications include diuretics or water pills, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers used to treat hypertension, and nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen. OTC sodium phosphate drug products include oral solutions taken by mouth and enemas used rectally.

The FDA advises consumers and healthcare professionals to read the drug facts label for OTC sodium phosphate drugs, use these products as recommended, and not exceed the labeled dose.

"Caregivers should not give the oral products to children 5 years and younger without first discussing with a health care professional," the agency advises. "Health care professionals should use caution when recommending an oral dose of these products for children 5 years and younger. The rectal form of these products should never be given to children younger than 2 years."

The FDA has previously issued warnings about the risk for kidney injury with the use of oral sodium phosphate drug products at higher doses for bowel cleansing before colonoscopy or other procedures, as reported by Medscape Medical News.

More information on the FDA warning is available on the agency's Web site.

To report problems with these or other products, contact MedWatch, the FDA's safety information and adverse event reporting program, by telephone at 1-800-FDA-1088; by fax at 1-800-FDA-0178; online at https://www.accessdata.fda.gov/scripts/medwatch/medwatch-online.htm; with postage-paid FDA form 3500, available at https://www.fda.gov/MedWatch/getforms.htm; or by mail to MedWatch, 5600 Fishers Lane, Rockville, Maryland 20852-9787.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.