After seeing a TV commercial advertising a children's medicine as "PPA free," I did a Web search to figure out what that meant. PPA is phenylpropanolamine, an ingredient in numerous decongestants and diet aids. In October, a U.S. Food and Drug Administration advisory panel recommended a ban on PPA, estimating that it causes 200 to 500 hemorrhagic strokes each year. Anticipating a ban, drug companies have come out with PPA-free versions of many products, including Acutrim, Comtrex, Dexatrim, Dimetapp and Robitussin. One small company is giddy about the problem.