Final answer:
Histamine 2 (H₂) receptor antagonists work by competing with histamine for binding sites on the parietal cells in the stomach. Histamine 2 (H₂) receptor antagonists work by competing with histamine for binding sites on the parietal cells in the stomach.
So, the correct answer is C.
Step-by-step explanation:
H₂ receptor antagonists, such as ranitidine and famotidine, compete with histamine at parietal cell binding sites to decrease gastric acid production, treating conditions like peptic ulcers and GERD. These medications, such as ranitidine (Zantac), famotidine (Pepcid AC), and cimetidine (Tagamet), are designed to decrease gastric acid production. They do so by preventing histamine from stimulating the H₂ receptors, which would otherwise lead to increased secretion of hydrochloric acid (HCl).
While they are often used in the treatment of peptic ulcers and gastroesophageal reflux disease (GERD), they are not antacids and should not be confused with other acid-reducing drugs like proton pump inhibitors (PPIs) such as omeprazole (Prilosec).
These medications can also be utilized to prevent and treat symptoms of heartburn associated with acid indigestion and sour stomach. It's crucial to differentiate that H₂-antihistamines target the digestive system to reduce stomach acid, whereas H₁-antihistamines are used to treat allergic reactions, including those affecting the nose and to combat issues like insomnia and motion sickness.
So, the correct answer is C) completing with histamine to binding sites on the parietal cells.