Esomeprazole 20 mg Acid Reducer Capsules, 14 ct, QC99635 Sale! This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. Compare to the Active Ingredient in Nexium 24 Hr. Treats frequent heartburn (occurs 2 or more days a week). Can take 1 to 4 days for full effect. Clinically proven to treat frequent heartburn.