奥美拉唑-Omeprazole

Omeprazole – Veterinary Summary

Drug Class: Proton Pump Inhibitor (PPI)

Mechanism of Action:

Omeprazole specifically inhibits the H⁺/K⁺-ATPase (proton pump) in the parietal cells of the gastric mucosa, suppressing gastric acid secretion at the final step of acid production. It strongly and persistently inhibits both basal and stimulated gastric acid secretion. Its acid-suppressing effect is more than 10 times stronger than cimetidine and lasts for more than 24 hours.

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💊 Indications

Used for the treatment of:

•Gastric and duodenal ulcers

•Gastroesophageal reflux esophagitis

•Zollinger–Ellison syndrome or mast cell tumor–related hyperacidity

•Prevention and treatment of gastric erosion or ulceration caused by NSAIDs

•Helicobacter pylori infection (as part of combination therapy)

•Acute gastritis and reflux esophagitis in dogs

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⚗️ Pharmacokinetics

Omeprazole is absorbed in the small intestine and rapidly distributed to the secretory canaliculi of parietal cells. It is converted to its active form in the acidic environment and covalently binds to the H⁺/K⁺-ATPase enzyme, leading to prolonged inhibition of acid secretion.

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Storage

•Store in a light-resistant, tightly sealed container at room temperature.

•Capsules contain fragile enteric-coated granules; avoid crushing or squeezing.

•When administered as a paste, mix the granules with fruit juice—do not use water, milk, or saline, which can degrade the drug.

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🐶 Dosage Guidelines for Dogs

Treatment PurposeDosageRouteFrequency

Ulcer therapy0.5–1 mg/kgOralOnce daily

Esophagitis0.7–2 mg/kgOralOnce or twice daily

Zollinger–Ellison syndrome, severe esophagitis0.75–1 mg/kgOralEvery 24 hours

H. pylori infection (triple therapy)Omeprazole 0.66 mg/kg q24h + Metronidazole 33 mg/kg q24h + Amoxicillin 11 mg/kg q12h + Sucralfate 0.25–0.5 g q8hOralCombined protocol

💡 Practical dose reference:

•<5 kg: 5 mg per dog (¼ capsule)

•5–20 kg: 10 mg per dog (½ capsule)

•20 kg: 20 mg per dog (1 capsule)

When using less than a full capsule, re-encapsulate the granules in a blank gelatin capsule to protect them from gastric acid degradation.

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⚠️ Safety and Precautions

Omeprazole is generally well tolerated in dogs. Chronic acid suppression may cause hypergastrinemia and gastric mucosal hypertrophy in laboratory animals; therefore, treatment duration should not exceed 8 weeks unless under veterinary supervision.

Use with caution in:

•Animals with hepatic or renal disease

•Pregnant or lactating animals

•Animals allergic to omeprazole or similar PPI drugs

Possible adverse reactions (rare):

•Decreased appetite, nausea, vomiting

•Diarrhea or constipation

•Flatulence

•Skin rash

•Proteinuria

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🔄 Drug Interactions

Omeprazole may interact with or affect the activity of the following drugs:

•Benzodiazepines, clarithromycin, clopidogrel, cyanocobalamin

•Cyclosporine, digoxin, ketoconazole, itraconazole, ampicillin, iron supplements

•Phenytoin (omeprazole may increase its effect)

•Rifampin, warfarin

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📚 References:

•Veterinary Drug Handbook

•Compiled and reviewed by Maopipi Veterinary Clinic

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