North American Veterinary Licensing Examination (NAVLE) Practice Test

Omeprazole functions as a proton pump inhibitor, which means it specifically inhibits the proton pump (H+/K+ ATPase) located in the parietal cells of the stomach lining. This action effectively reduces gastric acid secretion by blocking the final step of acid production in the stomach. By decreasing the amount of acid being produced, omeprazole is useful in treating conditions such as gastroesophageal reflux disease (GERD), peptic ulcers, and Zollinger-Ellison syndrome, where excessive stomach acid can lead to damage and discomfort.

The other choices refer to different mechanisms: cyclooxygenase blockers inhibit the enzyme involved in producing prostaglandins that mediate inflammation and pain; beta-adrenergic receptor agonists activate receptors that can cause bronchodilation; and H2-receptor antagonists block histamine at H2 receptors, leading to reduced gastric acid secretion, but through a different pathway than proton pump inhibitors. Understanding these distinct mechanisms helps clarify the specific role omeprazole plays in managing acid-related disorders.