Which drug is known for preventing the production of gastric acid?

The drug known for preventing the production of gastric acid is Cimetidine, commonly known by the brand name Tagamet. Cimetidine belongs to a class of medications called H2 receptor antagonists, which work by blocking the action of histamine on the stomach's parietal cells. This action reduces the amount of acid produced by the stomach, making it effective for treating conditions like peptic ulcers, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome, where excess gastric acid is a concern.

Other medications listed do not have this same function. Meclizine is an antihistamine used primarily to prevent and treat nausea, vomiting, and dizziness caused by motion sickness, focusing on vestibular disturbances rather than gastric acid production. Kaolin and pectin is a combination used as an anti-diarrheal and does not influence gastric acid secretion. Warfarin functions as an anticoagulant, working to prevent blood clots, and has no direct relationship with gastric acid production. Therefore, Cimetidine is the correct choice for preventing gastric acid production.