(Portland, OR) -- Oregon Senator Ron Wyden is leading a congressional investigation into the high cost of prescription medications and the roll of pharmacy benefits managers in pricing. About 85-percent of Americans get their drug prescriptions through a pharmacy benefits manager, or PBM. They are under fire for practices that watchdogs say drive up the cost of prescription medications, with independent pharmacies and consumers getting the worst of it. As chair of the U.S. Senate Finance Committee, Wyden led a hearing last week with a panel of experts on the PBM problem.