Gastrogard

• Chemical name: 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl) methyl]sulfinyl]-1H-benzimidazole. Empirical formula: C17H19N3O3S. Molecular weight: 345.42. Structural formula:

• Gastrogard (omeprazole) Paste for horses contains 37% w/w omeprazole and is available in an adjustable-dose syringe. Each syringe contains 2.28 g of omeprazole. Syringes are calibrated according to body weight and are available in boxes of 7 units or 72 units.

Storage Conditions

• Store at 68°F – 77°F (20-25°C). Excursions between 59°F – 86°F (15-30°C) are permitted.

• For treatment of gastric ulcers, Gastrogard Paste should be administered orally once-a-day for 4 weeks at the recommended dosage of 1.8 mg omeprazole/lb body weight (4 mg/kg). For the prevention of recurrence of gastric ulcers, continue treatment for at least an additional 4 weeks by administering Gastrogard Paste at the recommended daily maintenance dose of 0.9 mg/lb (2 mg/kg).

• Mechanism of Action: Omeprazole is a gastric acid pump inhibitor that regulates the final step in hydrogen ion production and blocks gastric acid secretion regardless of the stimulus. Omeprazole irreversibly binds to the gastric parietal cell's H+, K+ ATPase enzyme which pumps hydrogen ions into the lumen of the stomach in exchange for potassium ions. Since omeprazole accumulates in the cell cannaliculi and is irreversibly bound to the effect site, the plasma concentration at steady state is not directly related to the amount that is bound to the enzyme. The relationship between omeprazole action and plasma concentration is a function of the rate-limiting process of H+, K+ ATPase activity/turnover. Once all of the enzyme becomes bound, acid secretion resumes only after new H+, K+ ATPase is synthesized in the parietal cell (i.e., the rate of new enzyme synthesis exceeds the rate of inhibition).

• Pharmacodynamics: In a study of pharmacodynamic effects using horses with gastric cannulae, secretion of gastric acid was inhibited in horses given 4 mg omeprazole/kg/day. After the expected maximum suppression of gastric acid secretion was reached (5 days), the actual secretion of gastric acid was reduced by 99%, 95% and 90% at 8, 16, and 24 hours, respectively.

• Pharmacokinetics: In a pharmacokinetic study involving thirteen healthy, mixed breed horses (8 female, 5 male) receiving multiple doses of omeprazole paste (1.8 mg/lb once daily for fifteen days) in either a fed or fasted state, there was no evidence of drug accumulation in the plasma when comparing the extent of systemic exposure (AUC0-∞). When comparing the individual bioavailability data (AUC0-∞, Cmax, and Tmax measurements) across the study days, there was great inter- and intrasubject variability in the rate and extent of product absorption. Also, the extent of omeprazole absorption in horses was reduced by approximately 67% in the presence of food. This is evidenced by the observation that the mean AUC0-∞ values measured during the fifth day of omeprazole therapy when the animals were fasted for 24 hours was approximately three times greater than the AUC estimated after the first and fifteenth doses when the horses were fed hay ad libitum and sweet feed (grain) twice daily. Prandial status did not affect the rate of drug elimination. The terminal half-life estimates (N=38) ranged from approximately one-half to eight hours.

Gastrogard®
(omeprazole)
NADA 141-123, Approved by FDA

Caution: Federal (USA) law restricts this drug to use by or on the
order of a licensed veterinarian.

Indications: For treatment and prevention of recurrence of gastric
ulcers in horses and foals 4 weeks of age and older.

Dosage Regimen: For oral use in horses only. For treatment of
gastric ulcers, Gastrogard® (omeprazole) Paste should be administered
orally once-a-day for 4 weeks at the recommended dosage of 1.8 mg
omeprazole/lb body weight (4 mg/kg). For the prevention of
recurrence of gastric ulcers, continue treatment for at least an
additional 4 weeks by administering Gastrogard (omeprazole) Paste at
the recommended daily maintenance dose of 0.9 mg/lb (2 mg/kg).

NET WT. 6.15 g (2.28 g of omeprazole)

READ PACKAGE INSERT FOR FURTHER
INSTRUCTIONS AND IMPORTANT INFORMATION.

Warning: Do not use in horses intended for human
consumption. Keep this and all drugs out of the reach of children.

Storage: Store at 68°F - 77°F (20-25°C). Excursions between
59°F - 86°F (15-30°C) are permitted.

Marketed by: Merial LLC, Duluth, GA 30096-4640, U.S.A.

Made in Brazil

Customer Assistance: For more information, please call
1-888-637-4251. US Patent: 4255431 and 5708017

®Gastrogard is a registered trademark of the AstraZeneca
Group of Companies. ©2009 Merial. All rights reserved.

1824/01 / 36611, Rev. 02-2009

LOT
EXP

Gastrogard®
(omeprazole) Oral Paste for Equine Ulcers

Improves and Heals Gastric Ulcers

Prevents Gastric Ulcer Recurrence

Once-a-Day Dosing

NADA 141-123, Approved by FDA

Contains 7 Syringes
Individually Wrapped

Product 3661101

MERIAL