When Democrats take control of Congress in January, some lawmakers hope to push for access to cheaper prescription drugs from abroad.

Omnicare, the largest provider of pharmacy services to nursing homes in the United States, said yesterday that it had agreed to pay $49.5 million to settle claims by the federal government and 42 states that it overcharged them for drugs provided to the elderly.

Mixed messages about economic growth drained optimism out of the market this week, but new mergers helped rebuild momentum.

CVS and Caremark shares plunged on Wednesday as investors expressed concerns about both companies and their competitors.

The transaction, for more than $21 billion, would transform CVS into the nation’s preeminent manager of pharmacy benefits.

CVS is said to be in talks to buy Caremark, the biggest pharmacy benefits manager, for more than $21 billion.

Bristol-Myers said it lost up to $600 million in sales to a Canadian rival, causing a 65 percent earnings decline in the third quarter.