Treats Frequent Heartburn Occurring 2 Or More Days A Week. Omeprazole Magnesium Delayed-Release Tablets 20.6 mg/Acid Reducer. Three 14-Day Courses of Treatment. Uses. Treats frequent heartburn (occurs 2 or more days a week). Not intended for immediate relief of heartburn; this drug may take 1 to 4 full days for full effect.