The FDA has agreed to take down one of the big hurdles hampering U.S. sales of Vivus' newly approved weight drug Qsymia, but plenty more remain. Vivus ($VVUS) says the agency has agreed to lift a provision restricting sales to mail-order pharmacies, paving the way to getting the obesity drug into thousands of retail pharmacy outlets around the country. The biotech cheered the move, but also cautioned that it will take a full 90 days to make its way onto store shelves. And investors pushed shares up about 6% on the news. FiercePharma item