Don’t test your luck - equine stomach ulcer diagnosis deserves a proven treatment
/
In association with
Ulceration of the stomach is a common health problem among athletic horses around the world. The reported prevalence of ulcers in racing Thoroughbred or Standardbred horses is high, commonly quoted between 55% and 90%.1 The economic impact of this disease is difficult to calculate because the impact on athletic performance has not been accurately determined. However, there are well-defined costs attributable to diagnosis, medication and the labor required for treatment.
When it comes to cost associated with ulcer medication, it is often said that “the most expensive treatments are the ones that don’t work.” Proton pump inhibitors, of which omeprazole is considered the best studied in horses, make up one of the most commonly used classes of drugs for equine gastric ulcers. But while there are several omeprazole products on the market, are they all created equal? The simple answer is no.
Animal drugs are approved by the U.S. Food and Drug Administration (FDA) for use in specific species to treat particular conditions. To be legally marketed, animal drugs, with few exceptions, must meet the FDA’s stringent safety and efficacy standards. However, many animal drugs are manufactured and sold by compounding pharmacies, and as such are not FDA-approved brand-name drugs.
Compounded drugs can serve an important medical need for patients in certain circumstances, but they do not have the same safety, quality and effectiveness assurances as FDA-approved drugs. In addition, the FDA does not review the manufacturing methods used to make them or the accuracy of their labeling. Therefore, poor compounding practices can result in serious drug quality problems — such as bacterial or fungal contamination, or drugs that have either too much or too little active ingredient(s) — which can lead to serious patient injury and death. The American Association of Equine Practitioners (AAEP) advises: “Limit the use of compounded drugs to unique needs in specific patients.”2
There have been various headlines, articles, and research studies over the years regarding improperly compounded medications and their associated risks to horse health and welfare, and their financial implications. When it comes to stability and efficacy, compounded omeprazole products often don’t measure up. Compounded and illegally manufactured omeprazole products often have safety, efficacy, and production quality control problems like incomplete filling of syringes, air pockets, and variations in homogeneity (see Figure 1.).3
Figure 1. Radiographs of compounded and illegal omeprazole products shows inadequate syringe fill and air pockets in the products. From Wallace M. Radiographic Evaluation of Compounded and Illegal Over-the-counter Omeprazole Products (Abstract E47). ACVIM 2017
While it is vital to take every step to protect your horse's gastric health, it is a good idea to look closely when considering compounded omeprazole products. In laboratory testing, some compounded omeprazole products contained as little as 6% of their labeled value (see Figure 2.).4
In a 60-day in-vitro study comparing five compounded pastes to Gastrogard® (omeprazole), compounded formulations started as low as 63% of labeled concentration on day 0 and fell to as low as 17% on day 60.5 GASTROGARD concentrations remained stable and at label concentration throughout the study.
Figure 2. Active omeprazole vs. label claim in 10 compounded products
In another study involving 32 adult racehorses in active training, results suggested that while administration of Gastrogard® (omeprazole) was effective in promoting healing of gastric ulcers in these horses, administration of the compounded omeprazole suspension was ineffective.6
GASTROGARD is one of the most widely used prescription medications and the only FDA-approved oral formulation of omeprazole available in the United States for horses.
The omeprazole in GASTROGARD is specially protected allowing it to reach the site of absorption in the small intestine so that it can suppress gastric acid production to a level that allows ulcers to heal.7
In addition to premarket review, FDA-approved animal drugs are subject to requirements once they are on the market. For instance, manufacturers must submit adverse event reports — including reports of product defects — and provide information to the FDA related to safety, effectiveness, and manufacturing quality throughout the product’s lifetime. These reports allow the FDA to continue to monitor the safety and effectiveness of the drug after approval. Unlike manufacturers of FDA-approved animal drugs, compounders are not required to report adverse events and product defects.
What are the advantages of FDA-approved drugs?8
• Safety and efficacy based on thorough scientific review
• Meet quality, purity and potency specifications
• Continual monitoring ensures product performance
• Consistent manufacturing standards
Furthermore, FDA believes it is critically important to disclose risk information of prescription drugs appropriately and effectively to healthcare professionals and consumers. Important safety information of the drug can be found in its entirety on the package label and/or package insert. GASTROGARD is labeled for use in horses and foals 4 weeks of age and older. The safety of GASTROGARD paste has not been determined in pregnant or lactating mares. GASTROGARD is not to be used in horses intended for human consumption.
Knowledge is power when it comes to deciding whether to use compounded versus FDA-approved drugs. Do not hesitate to ask your veterinarian about the medications being used in your horses. At the end of the day, your horse’s health and welfare is worth becoming as educated as possible about gastric health, and how to best manage it.
IMPORTANT SAFETY INFORMATION: GASTROGARD safety has not been determined in pregnant or lactating mares. For use in horses and foals 4 weeks of age and older. Keep this and all drugs out of the reach of children. In case of ingestion, contact a physician. Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian.
For prescribing information, click here.
References:
1 Sykes BW, Hewetson M, Hepburn RJ, Luthersson N, Tamzali Y. European College of Equine Internal Medicine Consensus Statement — Equine Gastric Ulcer Syndrome in Adult Horses. J Vet Intern Med. 2015 Sep-Oct;29(5):1288-99.
2 Equine Veterinary Compounding Guidelines. 2005. Available at: http://www.aaep.org/pdfs/drug_compounding_guidelines.pdf. Accessed Dec. 17, 2009.
3 Wallace M. Radiographic Evaluation of Compounded and Illegal Over-the-counter Omeprazole Products (Abstract E47). ACVIM 2017. Available at: https://images.saymedia-content.com/.image/cs_srgb/MTQ4NzczNDgxOTU2MjU1NDEx/44465-acvim_poster_fa.pdf. Accessed May 28, 2020.
4 Data on file.
5 Stanley SD, Knych HK. Comparison of Pharmaceutical Equivalence for Commercially Available Preparations of Omeprazole. AAEP Proceedings. 2011;57:63.
6 Nieto JE, Spier S, Pipers FS, Stanley S, Aleman MR, Smith DC, Snyder JR. Comparison of Paste and Suspension Formulations of Omeprazole in the Healing of Gastric Ulcers in Racehorses in Active Training. J Am Vet Med Assoc. 2002 Oct 15;221(8):1139-43.
7 GASTROGARD product label.
8 Animal 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 Feb. 9, 2012.