Compare to Pepcid® AC active ingredient. Just one tablet of Original Strength Famotidine Tablets, 10 mg prevents and relieves heartburn due to acid indigestion brought on by eating and drinking certain foods and beverages. This gluten free heartburn medicine is intended for adults and children 12 years and over. Original Strength Famotidine Tablets, 10 mg helps prevent meal-induced heartburn when taken at least 15-60 minutes before eating. Lasts up to 12 hours.