• Open Access

Efficacy of Omeprazole Powder Paste or Enteric-Coated Formulation in Healing of Gastric Ulcers in Horses

Authors

  • K. Birkmann,

    1. Equine Department, Vetsuisse Faculty, Clinic for Equine Internal Medicine, University of Zurich, Zurich, Switzerland
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  • H.K. Junge,

    1. Equine Department, Vetsuisse Faculty, Clinic for Equine Internal Medicine, University of Zurich, Zurich, Switzerland
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  • E. Maischberger,

    1. Equine Department, Vetsuisse Faculty, Clinic for Equine Internal Medicine, University of Zurich, Zurich, Switzerland
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  • M. Wehrli Eser,

    1. Equine Department, Vetsuisse Faculty, Clinic for Equine Internal Medicine, University of Zurich, Zurich, Switzerland
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  • C.C. Schwarzwald

    Corresponding author
    1. Equine Department, Vetsuisse Faculty, Clinic for Equine Internal Medicine, University of Zurich, Zurich, Switzerland
    • Corresponding author: Prof. Dr Colin C. Schwarzwald, PhD, Dipl. ACVIM & ECEIM, Equine Department, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland. Tel: +41 44 635 86 97. Fax: +41 44 635 89 05. Email: cschwarzwald@vetclinics.uzh.ch.

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  • Correction made after online publication March 14, 2014: author names have been updated.
  • Previous presentation: Parts of this study have been presented at the 6th Congress of the European College of Equine Internal Medicine (ECEIM), Feb 8–9, 2013, Le Touquet, France, and at the Bicentennial Congress of the Swiss Veterinary Association (GST), June 6, 2013, Berne, Switzerland

Abstract

Background

GastroGard, an omeprazole powder paste formulation, is considered the standard treatment for gastric ulcers in horses and is highly effective. Gastrozol, an enteric-coated omeprazole formulation for horses, has recently become available, but efficacy data are controversial and sparse.

Objectives

To investigate the efficacy of GastroGard and Gastrozol at labeled doses (4 and 1 mg of omeprazole per kg bwt, respectively, PO q24h) in healing of gastric ulcers.

Animals

40 horses; 9.5 ± 4.6 years; 491 ± 135 kg.

Methods

Prospective, randomized, blinded study. Horses with an ulcer score ≥1 (Equine Gastric Ulcer Council) were randomly divided into 2 groups and treated for 2 weeks each with GastroGard followed by Gastrozol (A) or vice versa (B). After 2 and 4 weeks, scoring was repeated and compared with baseline. Plasma omeprazole concentrations were measured on the first day of treatment after administration of GastroGard (n = 5) or Gastrozol (n = 5).

Results

Compared with baseline (squamous score (A) 1.65 ± 0.11, (B) 1.98 ± 0.11), ulcer scores at 2 weeks ((A) 0.89 ± 0.11, (B) 1.01 ± 0.11) and 4 weeks ((A) 1.10 ± 0.12, (B) 0.80 ± 0.12) had significantly decreased in both groups (P < .001), independent of treatment (P = .7). Plasma omeprazole concentrations were significantly higher after GastroGard compared with Gastrozol administration (AUCGG = 2856 (1405-4576) ng/mL × h, AUCGZ = 604 (430-1609) ng/mL × h; P = .03). The bioavailability for Gastrozol was 1.26 (95% CI 0.56–2.81) times higher than for GastroGard.

Conclusions and Clinical Importance

Both Gastrozol and GastroGard, combined with appropriate environmental changes, promote healing of gastric ulcers in horses. However, despite enteric coating of Gastrozol, plasma omeprazole concentrations after single labeled doses were significantly higher with GastroGard.

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