PEPCID AC® Tablets work to prevent or relieve heartburn and acid indigestion. Containing the acid-reducer ingredient famotidine, these tablets control the production of excess stomach acid, preventing or relieving heartburn, acid indigestion, and upset or sour stomach brought on by eating or drinking certain food and beverages. You can take PEPCID AC® to control stomach acid for up to 12 hours. PEPCID AC® Tablets are easy to swallow and come in 30-count and 60-count packages.