Prilosec OTC® treats Frequent Heartburn! 24-Hour Heartburn Relief with One Pill a Day. Prilosec OTC is different from other over-the-counter heartburn medications. It targets acid production by directly shutting down many active acid pumps, and it works for up to 24 hours with one pill a day. This means you can get heartburn relief around the clock with one pill a day. No other over-the-counter heartburn medication works like that. Facts about Prilosec OTC: Itâ��s the first proton pump inhibitor (PPI) to be available over the counter for the treatment of frequent heartburn. Itâ��s for people with frequent heartburn (two or more days per week). One pill a day works to relieve heartburn for up to 24 hours. Prilosec OTC is to be used once a day for 14 days, or as directed by your doctor. Prilosec OTC is available over the counter for frequent heartburn. Use as directed for 14 days for treating frequent heartburn. Not for immediate relief. Just one pill per day gives complete relief. Omeprazole delayed-release tablets 20mg / acid reducer.