 but that painful burning stayed. So I made Prilosec OTC part of my morning routine. With just one pill each morning, Prilosec OTC prevents excess acid production, blocking heartburn day and night. Now I have a new nighttime routine. One pill a day, 24 hours, zero heartburn. With Prilosec OTC, it's possible while taking Prilosec OTC. Use as directed for 14 days to treat frequent heartburn, not for immediate relief. I made Prilosec OTC part of my morning routine.