Related Recall Of Over-The-Counter OSP Fleet Phospho-Soda, Which Is Subject Of Product Liability Lawsuits
(Posted by Tom Lamb at DrugInjuryWatch.com)
On December 11, 2008 the FDA issued by email a MedWatch Safety Alert which was titled "Oral Sodium Phosphate (OSP) Products for Bowel Cleansing: reports of acute phosphate nephropathy, Boxed Warning to be added to labeling".
According to this December 2008 Alert, the FDA was taking action because it had become aware of reports of a type of serious kidney injury, acute phosphate nephropathy, that was associated with the use of oral sodium phosphate products (OSP) for bowel cleansing prior to colonoscopy or other procedures. Further, some of these cases acute phosphate nephropathy cases occurred in patients who had not have any pre-existing, identifiable factors that would have put them at risk for developing this acute kidney injury.
For more information, the FDA directed patients and doctors to the MedWatch 2008 safety summary about this new Boxed Warning (also known as a black-box warning) for Visicol And OsmoPrep -- the only two prescription OSP products available in the U.S.
From there, for those who wanted more details, the MedWatch summary directed one to this FDA Drug Information Page, "Oral Sodium Phosphate (OSP) Products for Bowel Cleansing (marketed as Visicol and OsmoPrep, and oral sodium phosphate products available without a prescription)".
Taken from that page is what seems to be the FDA's current understanding of this OSP adverse reaction:
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. 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.
Individuals who appear to have an increased risk of acute phosphate nephropathy following the use of OSPs include persons: who are over age 55; who are hypovolemic or have decreased intravascular volume; who have baseline kidney disease, bowel obstruction, or active colitis; and who are using medications that affect renal perfusion or function (such as diuretics, angiotensin converting enzyme [ACE] inhibitors, angiotensin receptor blockers [ARBs], and possibly nonsteroidal anti-inflammatory drugs [NSAIDs]).
All of this was followed closely by a drug company announcement about some similar over-the-counter (OTC) products; from their press release, "C.B. Fleet Voluntarily Recalls its Fleet Phospho-soda Product after FDA Safety Alert":
Following the issuance of FDA's Safety Alert on Thursday stating that oral sodium phosphates bowel cleansing solutions should be available by prescription only, C.B. Fleet Company immediately announced a voluntary recall of their over-the-counter products Fleet® Phospho-soda® and Fleet® Phospho-soda® EZ-Prep® BowelCleansing System. The voluntary recall is directed to retailers and wholesalers.
Interestingly, one of these two products, Fleet Phospho-soda, is the subject of several ongoing product liability lawsuits that have been filed on behalf of patients with kidney damage who used this now-recalled C.B. Fleet OSP product.
These lawsuits filed against Fleet allege that the drug company marketed Phospho-soda at dosages higher than the FDA permitted for OTC oral laxatives containing sodium phosphate -- up to twice the permitted daily amount according to these lawsuits.
In turn, use of the higher dosage of Fleet Phospo-soda can leads to deposits of calcium and phosphate in the kidneys, a condition known as nephrocalcinosis. This damage to the kidneys is often permanent, and requires dialysis or even a kidney transplant.
Returning to the FDA's information, above, it seems that the risk of developing an OSP-induced kidney injury is increased in certain patients, such as those taking certain blood pressure medications or diuretics, and that the risk of this adverse reaction kidney damage increases with a patient's age.
We will continue to monitor this emerging drug safety issue, and we welcome any insight you may have about these several different OSP products causing kidney problems like acute phosphate nephropathy or nephrocalcinosis.