The recent human meningitis outbreak, caused by the injection of contaminated compounded steroid products prepared by the New England Compounding Center,1 has put compounding pharmacies into the daily headlines. With a death toll reaching 39 and a reported 656 cases nationwide as of late December,1 the outbreak has raised questions in consumers’ minds about drug safety.

But it isn’t just human drugs consumers should be concerned about. Compounding pharmacies prepare drugs for horses, as well. In 2009, a vitamin and mineral supplement prepared by Franck’s Compounding Lab in Ocala, FL included an excessive amount of one ingredient (selenium) that resulted in the death of 21 polo ponies.2 In other cases of questionable drug safety, illegal products that claim to be “the same as” name brand drugs are marketed to consumers, sometimes with devastating results. In 2006, a reported six horses died as a result of using an illegal clenbuterol product.3

Unfortunately, in these cases, the results of using non U.S. Food and Drug Administration (FDA) approved drugs were tragic. In other instances, while the unapproved and unproven products may not be particularly harmful, they may not contain the labeled amount of active ingredient4,5 or do what they claim to do.

Studies presented at the American Association of Equine Practitioners (AAEP) Convention in prior years have shown a wide range in the pharmaceutical equivalence of compounded drugs when compared to brand name drugs. In 2003, Scott Stanley, PhD, presented findings from a study evaluating compounded versions of the FDA-approved drugs ketoprofen, amikacin and boldenone. In the case of ketoprofen, one compounded preparation contained just one-half of the expected concentration.4 With amikacin, some compounded preparations had less drug, between 59 percent and 76 percent of what was stated on the label. Other compounded versions of the drug had more than the stated concentration: 112 percent and 140 percent.4

Dr. Stanley conducted similar research on compounded versions of omeprazole, presenting his findings at the 2011 AAEP Convention. The compounded omeprazole products ranged from more than 100 percent to approximately 63 percent of the concentration claimed on the label.5 After 60 days, the compounded versions lost potency, with the amount of active ingredient varying from 82 percent to as little as 17 percent.5

At the 2012 AAEP Convention, Dr. Stanley presented results from a similar study, this one comparing compounded formulations of clenbuterol with the FDA-approved version. His findings showed the compounded formulations varied from containing as little as 32 percent of the labeled concentration up to more than 316% of the labeled concentration.6

“What these studies have shown is that compounded versions of equine drugs, in many cases, do not contain the proper concentration of the active ingredient,” says April Knudson, DVM, equine specialist, Merial Large Animal Services. “If they don’t have enough of the active ingredient, it’s a natural conclusion they won’t work as well, if at all. If they have too much of the ingredient, it’s possible there will be a detrimental effect on the horse’s health, depending on the ingredient,” she says. Additionally, merely containing the same active ingredient as a brand name drug does not guarantee efficacy or safety. The proper formulation is often an essential part of making a safe and efficacious product.

How can horse owners be sure they are getting a product that is safe and will do what it claims on the label? By making sure that product is FDA approved.

Drugs that are approved by the FDA are:

• Tested in the target animal in field trials and in the laboratory.7
• Manufactured according to Good Manufacturing Practices, which ensures consistency.7
• Manufactured in inspected facilities that meet FDA guidelines.7
• Labeled with information that can be scientifically substantiated.7
• Advertised in such a way as to not be false or misleading.7
• Monitored following approval for adverse events.7

Because many of these unapproved drugs are made to look like the approved drugs, horse owners should be wary and do their homework. Whether a product has been FDA-approved can be determined by checking the searchable database at AnimalDrugs@FDA (http://www.accessdata.fda.gov/scripts/animaldrugsatfda/). Most generic and brand name drugs also feature a number on the label indicating FDA approval. In the case of brand name drugs, look for the six -digit New Animal Drug Application (NADA) and for generics, the Abbreviated New Animal Drug Application (ANADA) number.

“Horse owners have a lot of financial and emotional investment in their horses,” says Dr. Knudson. “Taking some time to research the products available and make educated decisions should help them keep their horses healthy in the long run.”

For more information about the types of products available and the importance of FDA approval, go to equinedrugfacts.com.

©2013 Merial Limited, Duluth, GA. All rights reserved. EQUIUGD1301 (01/13)

1 Centers for Disease Control and Prevention. Multistate Fungal Meningitis Outbreak Investigation. Available at: http://cdc.gov/HAI/outbreaks/currentsituation/. Accessed November 6, 2012.

2 Reuters. U.S. aims to bar drug-making lab in polo horse deaths. Available at:
http://www.reuters.com/article/2010/04/19/us-usa-polo-horses-idUSTRE63155P20100419. Accessed October 18, 2012.

3 The Blood-Horse. Horse Deaths in Louisiana Attributed to Illegal Clenbuterol. Available at: http://www.bloodhorse.com/horse-racing/articles/36479/horse-deaths-in-Louisiana-attributed-to-illegal-clenbuterol. Accessed October 18, 2012.

4 Stanley SD, Thomasy SM, Skinner W. Comparison for Pharmaceutical Equivalence of FDA-Approved Products and Compounded Preparations of Ketoprofen, Amikacin, and Boldenone. International Veterinary Information Service. Available at: http://www.ivis.org/. Accessed November 1, 2012.

5 Stanley SD, Knych HK. Comparison of Pharmaceutical Equivalence for Commercially Available Preparations of Omeprazole. AAEP Proceedings. 2011;57:63.

6 Stanley SD, Knych HK. Comparison of Pharmaceutical Equivalence for Compounded Formulations of Clenbuterol. AAEP Proceedings. 2012;58:573.

7 Amercian Health Institute and American Veterinary Medical Association and American Veterinary Distributors Association. Veterinary Compounding. Available at: http://www.aaep.org/siteadmin/modules/page_editor/images/files/AHI%20Compounding.pdf. Accessed November 1, 2012.