The shocking disclosure that a pharmacy error may have caused the deaths of 21 prized polo horses has prompted drug safety advocates to renew their calls for more oversight of what they say is a largely unregulated sector of the pharmaceutical industry.
The horse deaths are the latest to be linked to 'compounding,' a practice that traditionally involves pharmacists mixing or changing FDA approved medications to create medications for unique patient needs, such as creating a syrup for children who cannot swallow pills.
As the business of large-scale compounding emerged over the past decade, drug safety experts have raised concerns that these pharmacies may be manufacturing drugs outside of the oversight of the Food and Drug Administration.
"Compounding is this shadow industry that has been operating outside the public's periscope," said Larry Sasich, pharmacist and an assistant professor at the Lake Erie College of Medicine. "Consumers don't know that these products are not FDA-approved."
In 2007, investigators in Oregon determined that errors in compounded medications caused at least two deaths after a Texas pharmacy supplied an alternative medicine clinic with doses of a drug that was eight times the standard level, according to an article published in the Journal of the American Medical Association.
The drug, an intraveous form of colchicine, was being used by the clinic to treat back pain, a use that had not been approved by the FDA.
L.D. King, a spokeperson for the International Academy of Compounding Pharmacists, said in a statement that compounding pharmacists are "strictly regulated at the state level," where regulators are "in the best position to inspect local pharamacy operations, develop appropriate regulations, and respond to any problems that may arise."
Sasich says that state regulators often lack the resources for adequate enforcement, and find it difficult to investigate compounders who supply drugs across state lines. Public health officials have also raised concerns that the patchwork of state-by-state oversight makes it difficult to judge the full extent of any threat to public health and safety.
From 1990 to 2007, the FDA received more than 200 voluntary reports of adverse events involving compounded drugs from 1990 to 2007, according to an agency publication. Compounding pharmacies, however, are not required to report their errors to the FDA or any other federal authority.
"People are being injured, but we don't know how many," said Sasich. "This may be the tip of the iceberg."
Drug safety groups and some pharmacists have also warned of an unreported epidemic of pharmacy errors at retail pharmacies.
In 2007, ABC News teamed up with pharmacy experts at Auburn University to conduct an undercover field test of prescription dispensing at 100 chain drug stores. The study found that in more than one in five cases, chain pharmacies made some type of error in filling their prescriptions.