Phospho soda was an

over the counter Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid prescr ...

saline

laxative Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation. Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...

produced by the C.B. Fleet Company in Lynchburg, Va. Phospho soda consisted mostly of monobasic sodium phosphate monohydrate and dibasic sodium phosphate heptahydrate. Phospho soda is often taken in a double dose (the usual 45ml dose, followed by a second 45ml dose 6 hours later), to prepare for colonoscopy. It is still used outside the US. An amount of Phospho soda (normally 1.5

fluid ounce A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called ''capacity'') typically used for measuring liquids. The British Imperial, the United States customary, and the United ...

or 45 ml) is usually mixed with water or other clear liquids such as

ginger ale Ginger ale is a carbonated soft drink flavoured with ginger. It is consumed on its own or used as a mixer, often with spirit-based drinks. There are two main types of ginger ale. The golden style is credited to the Irish doctor Thomas Joseph ...

. This preparation usually results in a

bowel movement Defecation (or defaecation) follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus. The act has a variety of names ranging fro ...

anywhere from 30 minutes to 6 hours after it is taken. Phospho soda is also available in various flavors to make it more palatable.

Safety issues

The use of Phospho soda has been known to lead to acute phosphate nephropathy. According to the

U.S. Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

(FDA), "Acute phosphate nephropathy is a form of acute kidney injury that is associated with deposits of calcium-phosphate crystals in the renal tubules that may result in permanent renal function impairment. Acute phosphate nephropathy is a rare, serious adverse event that has been associated with the use of OSPs ral sodium phosphates The occurrence of these events was previously described in an Information for Healthcare Professionals sheet and an FDA Science Paper issued in May 2006. Additional cases of acute phosphate nephropathy have been reported to FDA and described in the literature since these were issued." Fleet’s Phospho-soda products have been linked to kidney damage since the 1990s. On December 11, 2008, the FDA issued a Safety Alert stating that "FDA has become aware of reports of acute phosphate nephropathy, a type of acute kidney injury, associated with the use of oral sodium phosphate products (OSP) for bowel cleansing prior to colonoscopy or other procedures. These products include the prescription products, Visicol and OsmoPrep, and OSPs available over-the-counter without a prescription as laxatives (e.g., Fleet Phospho-soda). In some cases when used for bowel cleansing, these serious adverse events have occurred in patients without identifiable factors that would put them at risk for developing acute kidney injury ... The agency is equally concerned about the risks associated with the use of OSP products that are available over-the-counter (OTC), for example, Fleet Phospho-soda, when used at higher doses for bowel cleansing."

Recall

Following FDA's Alert, C.B. Fleet recalled its Fleet Phospho-Soda Products.

Use as a laxative

Phospho soda can be used for a general laxative, but is not recommended. The dosage then is best cut in half and used only once instead of twice. Phospho soda works by drawing liquid from the body into the colon, therefore it can cause severe

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

, especially if not used properly. Usage in this context is highly recommended to be performed only with a doctor's knowledge and consent.

Use as preparation for colonoscopy

When Phospho soda is used as preparation for colonoscopy, 1.5 fluid ounces (45ml), mixed with an equal amount of water or any clear liquid and followed by 8 oz of water, is taken, followed by a second dose 6 hours later (3 oz total). It will cause very loose, eventually watery stools, usually starting within an hour or so and lasting several hours. A 2007 study showed that in patients with decreased renal function, Phospho soda may worsen renal impairment compared to

polyethylene glycol Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular we ...

-based laxatives. In patients without kidney problems, no difference was observed.

Litigation

Since late 2004, there has been a great deal of litigation in both state and federal courts alleging renal injury following the use of Fleet Phospho-Soda. On June 23, 2009, the United States Judicial Panel on Multi District Litigation consolidated all federal Oral Sodium Phosphate Solution lawsuits to the Northern District of Ohio, before the Honorable Ann Aldrich. Additional documents from Phospho-Soda lawsuits have been published at the website DangerousDrugs.us.{{cite web , url=http://www.dangerousdrugs.us/ , title=Home , website=dangerousdrugs.us

References

Laxatives