The effects of dose and diet on the pharmacodynamics of esomeprazole in the horse.

Authors: Sykes B W, Underwood C, Mills P C

Journal: Equine veterinary journal

DOI: 10.1111/evj.12670 PubMed: 28117490Log in to save

Summary

# Editorial Summary: Esomeprazole Dosing and Dietary Effects in Horses Gastric ulcer syndrome remains a significant welfare concern in equine practice, yet optimal proton pump inhibitor (PPI) dosing strategies remain unclear. Sykes and colleagues investigated how esomeprazole dose (0.5 versus 2.0 mg/kg bodyweight once daily) and dietary composition (high grain/low fibre versus ad libitum hay) affected intragastric pH suppression over five consecutive days in six instrumented Thoroughbreds, using continuous 23-hour pH monitoring. Both higher dosing and the high grain/low fibre diet produced superior acid suppression, with the 0.5 mg/kg dose in high grain conditions and 2.0 mg/kg dose on hay-only feeding achieving pH suppression comparable to or exceeding human therapeutic standards; notably, a cumulative effect developed over the five-day study period, with Day 5 suppression substantially better than Day 1. For practitioners, these findings suggest that esomeprazole warrants consideration as an alternative to omeprazole and that dietary management—specifically limiting concentrate intake or feeding ad libitum forage with higher esomeprazole doses—may optimise ulcer treatment, though direct clinical efficacy trials comparing the two PPIs are still needed to guide evidence-based therapeutic recommendations.

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Practical Takeaways

•Esomeprazole shows promise for treating equine gastric ulcers but requires 5+ days to reach optimal acid suppression; early treatment response will be suboptimal
•Higher doses (2.0 mg/kg) appear more effective than lower doses (0.5 mg/kg), and diet composition affects treatment efficacy—consider dietary management alongside medication
•Direct comparison studies between esomeprazole and omeprazole are needed before changing established treatment protocols

Key Findings

•Esomeprazole at 2.0 mg/kg bwt produced higher acid suppression (%tpH>4) compared to 0.5 mg/kg bwt dose
•High grain/low fibre diet resulted in higher acid suppression than ad libitum hay diet
•Cumulative effect observed with significantly greater acid suppression on Day 5 compared to Day 1 of treatment
•At measurement point 1, esomeprazole exceeded human therapeutic breakpoints for 0.5 mg/kg in high grain/low fibre diet and 2.0 mg/kg in hay diet

Conditions Studied

equine gastric ulcer syndrome

Related References

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