Final answer:
Cimetidine and famotidine are H2-receptor antagonists that reduce stomach acid secretion by inhibiting histamine action at the H2 receptors on gastric parietal cells, thus treating ulcers, GERD, and Zollinger-Ellison syndrome.
Step-by-step explanation:
Mechanism of Action for Cimetidine and Famotidine
The mechanism of action for both cimetidine and famotidine involves their role as H2-receptor antagonists. These medications work by competitively inhibiting histamine at the H2 receptors found on the parietal cells of the stomach. This inhibition leads to a decrease in gastric acid secretion, both in volume and acidity, which is beneficial in the treatment of conditions such as peptic ulcers, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome.
They are especially effective in treating symptoms of heartburn associated with acid indigestion and sour stomach. While these H2 blockers manage acid production, it is important to note that they do not kill the bacteria Helicobacter pylori, which is often the cause of most ulcers, nor do they serve as antacids, which neutralize existing stomach acid.
Unlike H2 blockers, proton pump inhibitors, such as omeprazole, inhibit the enzyme system responsible for pumping acid into the stomach, providing a more prolonged reduction of stomach acid production.