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| | ===Proton-pump inhibitors (PPIs)=== | | ===Proton-pump inhibitors (PPIs)=== |
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| − | PPIs irreversibly bind to the H+K+-ATPase proton pump of the parietal cell and block the secretion of hydrogen ions. These agents are more effective than H2 antagonsists as their action is receptor-independent, it blocks the final pathwya of acid secretion and.(EGUC) | + | PPIs irreversibly bind to the H+K+-ATPase proton pump of the parietal cell and block the secretion of hydrogen ions. These agents are more effective than H2 antagonsists as their action is receptor-independent,(EGUC) blocking the final pathway of acid secretion and they have a prolonged effect allowing for once-daily dosing.((Brown and Rees 1994). Papich 1993, Sanchez) '''Omeprazole (Gastroguard)''', a subsituted benzimidazole, is currently licensed for use in horses. At a dose rate of 4mg/kg per day omeprazole has proven effective in reducing the severity of gastric ulcers in Thoroughbred horses in active race training (Vatistas 1999) and no adverse effects have been observed. |
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| − | Omeprazole, one of 2 compounds in this class currently licensed in the United States for use in man, is now licensed for use in horses. It has demonstrated an excellent efficacy and safety profile. In double-blind, placebo-controlled field trials, omeprazole paste, administered at 4 mgkg bwt was effective in eliminating or substantially reducing the severity of gastric ulcers. At this dose rate, pH >6 persisted for 24 h after the last treatment. In human medicine, omeprazole has been approved for long term and prophylactic use in patients with erosive oesophagitis. This is meaningful, because ulcers in the squamous portion of the equine stomach are most prevalent (>go%) and resemble the human form of erosive oesophagitis.(EGUC)
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| − | Treatment of uncomplicated equine peptic ulcer disease
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| − | Omeprazole has the advantages that:
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| − | It is licensed for use in horses
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| − | Its efficacy has been demonstrated in controlled clinical trials
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| − | Its ease of administration and once-daily dosing promotes compliance with a recommended treatment
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| − | strategy.(EGUC)
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| − | . One important advantage of proton pump inhibitors is their ability to inhibit acid production for 24 h with once-a-day dosing (Papich 1993). The recommended dose of oral omeprazole is 4.0 mgkg bwt every 24 h.(Orsini)
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| − | | + | one potential problem may be that increasing gastric pH may allow bacterial overgrowth in the small intestine by preventing the entry of organisms normally inhibited by gastric acidity. Consequently, further studies are required to determine the long-term efficacy and safety of omeprazole in horses. |
| − | Omeprazole, a substituted benzimidazole Omeprazole inhibits H+K+ATPase, the enzyme responsible for the final production of acid by parietal cells. In man, it has recently been shown that healing of erosive oesophagitis with antisecretory drugs is directly correlated to both the duration of acid suppression over a 24 h period and the elevation of intraoesophageal pH above 4 for at least 96% of the 24 h period (Tibbling 1993). In horses, orally administered omeprazole has been shown to increase stomach pH above 4 and to significantly inhibit gastric secretion for at least 27 h after treatment (Bough et al. 1995) In addition, omeprazole has a longer duration of action than the H2 receptor antagonists and, consequently, only requires once daily dosing (Brown and Rees 1994). No side-effects were observed in any of the horses in our study. Similarly, in 2 studies in which omeprazole was administered orally to horses over a 5 day period no adverse effects were noted (Ryberg et al. 1989; Bough et al. 1995). At the present dosage, omeprazole appears safe for use in horses, although further studies are required. As with human individuals suffering GERD (Gunasekaran and Hassall 1993), once omeprazole treatment was stopped in the horses, ulceration returned within 2 weeks. Presumably the same factors responsible for the development of ulcers in horses were still present at the end of the trial. In man, long-term treatment of GERD has been achieved by placing patents on a maintenance dose of omeprazole (Gunasekaran and Hassall 1993). Although no side-effects were observed in human patients receiving long-term omeprazole therapy (Goldberg
| + | Acceptability of omeprazole as a paste was, in general, excellent. Further studies are required to determine the optimal dosage and long-term safety of omeprazole in horses. (Vatistas 1999) |
| − | 1992; Gunasekaran and Hassall 1993), one potential problem may be that increasing gastric pH may allow bacterial overgrowth in the small intestine by preventing the entry of organisms normally inhibited by gastric acidity. Consequently, further studies are required to determine the long-term efficacy and safety of omeprazole in horses.
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| − | Acceptability of omeprazole as a paste was, in general, excellent. Omeprazole, administered once daily at the dosage in this study, was effective in reducing the severity of gastric ulcers in Thoroughbred horses in active race training. Further studies are required to determine the optimal dosage and long-term safety of omeprazole in horses. (Vatistas 1999) | |
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| | Equine Vet J. 2008 Jan;40(1):41-4. | | Equine Vet J. 2008 Jan;40(1):41-4. |