Kollias-Baker found that omeprazole was readily detected in the bloodstream for eight to 12 hours after administration of the drug. The liquid compounded product was only detectable once, at seven hours after administration. The levels of omeprazole that were detected also were significantly higher than those of the compounded drug. Dr. James Orsini of the University of Pennsylvania says another concern about compounded gastric ulcer medications is the shelf life of these products is highly variable, as is the concentration of the drug in each batch. "Based on what we know of the equine gastric ulcer system," Orsini says, "these animals (receiving compounded drugs) can have further performance problems, eat poorly, and lose weight, which are signs and symptoms of the disease."
Scientists are warning horse owners and veterinarians to be cautious about using compounded (private pharmacy-mixed) gastric ulcer medications. One study showed that a compounded product was not absorbed very well, writes Stephanie Church in the May edition of The Horse. There also might be problems with the shelf life of compounded ulcer medications. Marketers of the compounded ulcer drugs claim they are as effective as omeprazole, a more expensive product that has been approved by the Food and Drug Administration (FDA). Omeprazole is sold under the brand name GastroGard. Dr. Cynthia Kollias-Baker of the University of California, Davis, recently completed a project that compared omeprazole to compounded ulcer medications. She became interested in the issue when asked by veterinary clinics whether a compounded product could be used interchangeably with omeprazole. She predicted the compounded drug would not be absorbed and utilized, and her research upheld her theory.