Pharmacokinetics and pharmacodynamics of pantoprazole in clinically normal neonatal foals.
BACKGROUND
Proton pump inhibitors (PPIs) are a mainstay of treatment for acid-related ulceration in man and horses. Currently, only an oral preparation of omeprazole is approved for use in horses in the USA. Intravenous administration of a PPI would provide a useful therapeutic alternative for those foals in which oral medication is not feasible.


OBJECTIVE
To investigate the pharmacokinetics and pharmacodynamics of pantoprazole following i.v. or intragastric administration in healthy neonatal foals.


METHODS
Seven healthy foals age 6-12 days at the start of the study were evaluated. Treatments included no drug administration, i.v. pantoprazole (1.5 mg/kg bwt) and intragastric pantoprazole (1.5 mg/kg bwt). Intragastric pH was recorded for 24 h after drug administration for pharmacodynamic evaluation. Plasma pantoprazole concentrations were measured using high-performance liquid chromatography.


RESULTS
Plasma concentrations of pantoprazole were detectable at the 5 min sampling point following i.v. or intragastric administration. Bioavailability of intragastric-administered pantoprazole was 41%. Baseline mean hourly pH was 1.5-6.1. There was a statistically significant increase in mean hourly pH relative to untreated foals 2-24 h after i.v. or intragastric pantoprazole administration.


CONCLUSIONS
Based on these data, i.v. or intragastric administration of pantoprazole results in a significant, prolonged increase in intragastric pH.


CONCLUSIONS
The i.v. formulation of pantoprazole may provide a clinically useful alternative means of acid suppression in foals unable to tolerate enteral administration of a PPI, such as those with pyloric outflow obstruction.
Ryan
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Island Whirl Equine Colic Research Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, PO Box 100136, University of Florida, Gainesville, Florida 32610-0136, USA.
Sanchez
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LC
Giguère
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Vickroy
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D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D000897:Anti-Ulcer Agents / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D001562:Benzimidazoles / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005260:Female; D005745:Gastric Acidity Determination / Q000662:veterinary; D005753:Gastric Mucosa / Q000378:metabolism; D006736:Horses / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007275:Injections, Intravenous / Q000379:methods / Q000662:veterinary; D008297:Male; D009853:Omeprazole / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D000077402:Pantoprazole; D054328:Proton Pump Inhibitors; D011897:Random Allocation; D013270:Stomach / Q000187:drug effects; D013454:Sulfoxides / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D054328:Proton Pump Inhibitors; D013454:Sulfoxides; D000077402:Pantoprazole; D009853:Omeprazole