Ineffective ingredient could make Dayquil, Sudafed and others disappear from store shelves

Pharmacies could pull common over-the-counter cold medications including Dayquil, Sudafed and Theraflu, from store shelves after Food and Drug Administration experts determined one of their main ingredients doesn't work.  

That could leave consumers scrambling to find alternatives for relief from nasal congestion, and drugmakers hurrying to devise new drug formulations to make profits. 

Drugs like Sudafed, from pharmaceutical company Johnson & Johnson, are part of a roughly $2.2 billion market for oral decongestants. Products with formulations that contain phenylephrine, the drug FDA experts deemed ineffective, make up about four-fifths of that market.