Never exceed dose of constipation drugs containing sodium phosphate, FDA warns

ST LOUIS (MD Consult) - On January 8, 2014, the US Food and Drug Administration (FDA) issued an alert concerning the use of over-the-counter (OTC) sodium phosphate drugs to treat constipation. The agency is warning that using more than 1 dose in 24 hours of such drugs can cause rare but serious harm to the kidneys and heart, and even death. These drug products include oral solutions and enemas. They are marketed under the brand-name Fleet, and as store brands and generic products. They are available as single-ingredient drug products, containing either sodium biphosphate or sodium phosphate, and as combination drug products containing both ingredients. The FDA reviewed the Adverse Event Reporting System database from 1969 through 2012 and the medical literature from 1957 through August 2013 for cases describing serious adverse events associated with the of over-the-counter (OTC) sodium phosphate drug products used to treat constipation. The agency identified 54 cases describing serious adverse events in 25 adults and in 29 children. These reports described severe dehydration and changes in serum electrolytes levels associated with taking more than the recommended dose of OTC sodium phosphate products, resulting in serious adverse effects on organs (eg, kidneys and heart) and in some cases resulting in death. These serum electrolytes include calcium, sodium, and phosphate. 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. Some persons may be at higher risk for potential adverse events when the recommended dose of OTC sodium phosphate is exceeded. This includes young children, persons older than 55 years, patients with dehydration, kidney disease, bowel obstruction, or bowel inflammation, and patients who receive medications that may affect kidney function. These medications include diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers used to treat hypertension, as well as nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen. 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.