What is the mechanism of action of ranitidine?

Ranitidine works primarily by blocking H2 receptors in the stomach. These receptors are responsible for the stimulation of acid secretion by the parietal cells in the gastric mucosa. When ranitidine binds to these H2 receptors, it effectively inhibits the action of histamine, a key mediator in the stimulation of gastric acid production. As a result, this leads to a reduction in gastric acid secretion, which helps in the treatment of conditions like gastroesophageal reflux disease (GERD) and peptic ulcers.

The other options, while related to gastric acid and its management, do not accurately describe the specific mechanism by which ranitidine operates. Proton pump inhibitors, for example, work by directly inhibiting the H+/K+ ATPase enzyme in the gastric parietal cells, while neutralizing stomach acid refers to the action of antacids, and stimulating gastric secretion suggests an increase in acid production contrary to the action of ranitidine. Therefore, the correct understanding of ranitidine’s function hinges on its role in blocking H2 receptors, leading to decreased secretion of gastric acid.