Comparison of esomeprazole and omeprazole in the treatment of equine ulcers

Esomeprazole is sold OTC as Nexium and a number of generic products. They are sold as capsules containing tiny coated granules of medication that help get it through the stomach with the medication intact. In this 2009 study, Nexium was found to be effective at increasing stomach ph in horses:

Preliminary Study of Gastric Acidity in Thoroughbred Horses at Rest after Enteral Administration of Esomeprazole Magnesium (Nexium).

The regulation of gastric secretion is of crucial impor-tance to the equilibrium of the gastroenteric system. Despite the large number of factors involved in the causes of peptic illnesses, pH ¼ 4 is considered the threshold between physiologic and deleterious effects of stomach acid secretion. With the aim of maintaining pH greater than 4, proton-pump inhibitors, such as eso-meprazole magnesium (NEXIUM), have shown excel-lent results in the control of acid secretion. Aimed at examining the action of this drug in the control of pH levels of gastric secretion in thoroughbreds, a single dose of 40 or 80 mg of esomeprazole magnesium was administered daily, and pH was determined serially for 5 consecutive days. The results obtained corroborated the efficacy of esomeprazole magnesium in the control of gastric pH at both doses tested, with 100% of the mean pH being greater than 5. Moreover, no statistical difference was noted between the two doses tested.

The next study compares omeprazole and esomeprazole given as a buffered paste. The two studies and many anecdotal reports suggest that oral generic esomeprazole is effective and much cheaper than Gastro-Guard®. We need a direct comparison for this to be known for sure.
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Comparison of oral esomeprazole and oral omeprazole in the treatment of equine squamous gastric disease
Equine Vet J. 2023 Sep 7. doi: 10.1111/evj.13997. Online ahead of print.
Authors
Tania Sundra 1 , Sarah Gough 2 , Gabriele Rossi 3 , Erin Kelty 4 , David Rendle 5
Affiliations

1 Avon Ridge Equine Veterinary Services, Brigadoon, Western Australia, Australia.
2 Hunter Equine Centre, Scone, New South Wales, Australia.
3 School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, Western Australia, Australia.
4 School of Population and Global Health, The University of Western Australia, Crawley, Western Australia, Australia.
5 EMT Consulting, Devon, UK.

PMID: 37678812
DOI: 10.1111/evj.13997

Abstract
in English, German

Background: Oral omeprazole is the accepted treatment for equine squamous gastric disease (ESGD); however, it is not universally effective. Esomeprazole results in more consistent and pronounced acid suppression in men and is more effective than omeprazole in the treatment of oesophageal and gastric disease. Pharmacodynamic and pilot clinical studies have indicated esomeprazole might also be more effective than omeprazole in horses.

Objectives: To compare the efficacy and safety of oral esomeprazole and omeprazole pastes in the treatment of ESGD and, where present, concurrent equine glandular gastric disease (EGGD).

Study design: Randomised, single-blinded controlled trial.

Methods: Horses presenting with grade ≥2 ESGD lesions were randomly allocated to receive 4 mg/kg of either a buffered esomeprazole or omeprazole paste orally once daily for 28 days before gastroscopy being repeated within a further 3 days. Videos and images were anonymised and subsequently graded blind by one researcher. The severity of ESGD (and EGGD) lesions before and after treatment, and thereby treatment responses, were compared using univariable logistic regression.

Results: A higher proportion of horses had ESGD healing in response to esomeprazole treatment (63/74, 85%) than with omeprazole treatment (43/73, 59%) (odds ratio [OR]: 4.00, 95% confidence interval [CI]: 1.81, 8.82, p = 0.001). In a subset of horses that had concurrent EGGD, a greater proportion of the horses treated with esomeprazole had lesions ≤grade 1 (esomeprazole 28/51, 55%; omeprazole 6/24, 25%; OR: 3.65, 95% CI: 1.25, 10.71, p = 0.02) Using grade 0 as the benchmark for EGGD healing, the difference remained significant (OR: 4.44, 95% CI: 1.33, 14.85, p = 0.02).

Main limitations: It may not be possible to extrapolate these results to other populations with different signalment or management.

Conclusions: Oral-buffered esomeprazole was a more effective treatment for ESGD (and concurrent EGGD) than oral-buffered omeprazole.