And this means that the cost of many popular drugs has risen even faster. Merck, for example, now sells daily 10-milligram pills of Singulair, the blockbuster asthma drug, at a wholesale price of $1,330 a year — $147 more than last year. Singulair is now selling at retail, on drugstore.com, for nearly $1,478 a year.

The drug companies “can charge what they want — it’s not fair,” Eric White, the 42-year-old owner of a small jewelry store in Queens, said as he left a pharmacy recently.

Despite having drug insurance, Mr. White says he now pays $110 a month out of pocket for two brand-name allergy medicines, even as he has cut prices in his jewelry store by at least 40 percent to keep customers coming through the door.

He shook his head. “What can I do?” he said. “I need my medicines.”

The drug industry has actively opposed some of the cost-cutting provisions in the House legislation, which passed Nov. 7 and aims to cut drug spending by about $14 billion a year over a decade.

But the drug makers have been proudly citing the agreement they reached with the White House and the Senate Finance Committee chairman to trim $8 billion a year — $80 billion over 10 years — from the nation’s drug bill by giving rebates to older Americans and the government. That provision is likely to be part of the legislation that will reach the Senate floor in coming weeks.

But this year’s price increases would effectively cancel out the savings from at least the first year of the Senate Finance agreement. And some critics say the surge in drug prices could change the dynamics of the entire 10-year deal.

Image Stephen W. Schondelmeyer, a pharmaceutical economics professor at the University of Minnesota, said, “When we have major legislation anticipated, we see a run-up in price increases.” Credit... Allen Brisson-Smith for The New York Times

“It makes it much easier for the drug companies to pony up the $80 billion because they’ll be making more money,” said Steven D. Findlay, senior health care analyst with the advocacy group Consumers Union.