Guidelines for OSP use

In light of recent black box warnings concerning the use of OSP products, the FDA urges caution for use of both prescription and OTC products

Patients routinely take prescription OSP products to cleanse the bowel before a colonoscopy (colon examination) and other medical procedures. Additionally, some people take over-the-counter (OTC) laxative products, for example, Fleet Phospho-soda, at higher doses for bowel cleansing. When used for bowel cleansing, these products have the same risks as prescription OSP products.

In light of reports that OSP products have been linked to a severe form of kidney injury called acute phosphate nephropathy, the FDA has recommended that consumers do not use OTC OSPs for bowel cleansing.

The FDA also has called for a black box warning – the most severe warning – for prescription OSP products. The FDA has also directed the manufacturer of these products to develop a risk evaluation and mitigation strategy (REMS), distribute a Medication Guide to alert patients to the risk of acute kidney injury associated with the use of these products, and to conduct a post-marketing clinical trial to further assess the risk of acute kidney injury with the use of these products.

The FDA offers these general cautions for the use of OSP products:

OSP products should not be used by children under 18 years of age or in combination with other laxative products containing sodium phosphate.

FDA is recommending that OSP prescription products be used with caution for bowel cleansing by the following high risk groups:

  • people over 55 years of age
  • people who suffer from dehydration, kidney disease, acute colitis, or delayed bowel emptying
  • people taking certain medicines that affect kidney function, such as diuretics (fluid pills), angiotensin converting enzyme inhibitors (medications that lower blood pressure) angiotensin receptor blockers, (used to treat high blood pressure, heart or kidney failure) and possibly nonsteroidal anti-inflammatory drugs (similar to ibuprofen and other arthritis medications).
  • Documented cases of acute phosphate nephropathy include 21 patients who used an OSP solution (such as Fleet Phospho-soda or Fleet ACCU-PREP) and one patient who used OSP tablets (Visicol).