Major drug companies took hefty price increases in the U.S., in some cases more than doubling listed charges, for widely used medications over the past five years, a Reuters analysis of proprietary data found. Prices for four of the nation's top 10 drugs increased more than 100 percent since 2011, Reuters found. Six others went up more than 50 percent. Together, the price increases on drugs for arthritis, high cholesterol, asthma and other common problems added billions in costs for consumers, employers and government health programs. Extraordinary price hikes by two small companies, Turing Pharmaceuticals and Valeant Pharmaceuticals International Inc ... drew new attention to drug costs. Turing expected to book $200 million by raising the price of Daraprim, an antiparasitic used for a rare infection, by 5,000 percent, according to company documents released by Congressional investigators. Routine price increases by bigger players may draw less attention, but they add up. Sales for the top 10 drugs went up 44 percent to $54 billion in 2014, from 2011, even though prescriptions for the medications dropped 22 percent, according to IMS Health data. Even after discounts, pharmacy benefit managers told Reuters they pay annual price increases on top medications of up to 10 percent. By comparison, the U.S. consumer price index rose an average of 2 percent annually over the last five years.