NASHVILLE, Tenn. — Tennessee makes the third state this year, joining Kentucky and Nevada, that is considering state legislation to mandate the sale of pseudoephedrine as prescription-only. That could prove a big concern for the legitimate market for PSE products on account of the potential snowball effect such legislation could have on neighboring states. According to a government review staff in Kentucky, at least 97.8% of all PSE sales are bought for legitimate use.