WASHINGTON (CNN) -- Charlotte Walton, 66, was one of dozens of seniors who used to travel by bus to Canada to buy her prescription drugs at a fraction of the cost.
"There, I saved half the price of what I would have paid here in the United States," Walton said.

A congressional amendment passed by the Senate on Wednesday will allow Walton's local pharmacist to re-import her prescriptions from Canada at the cheaper price the Canadian government negotiates for its national health care patients.

Walton says the bill will help many seniors who are having trouble paying for their prescriptions.

"My husband worked five years past his retirement to put a few bucks away so we could live comfortably," she said, "but that isn't going to last long with the price of drugs they have right now."

But the man who organized the bus trips that helped Walton get cheaper medications, John Marvin of the National Council of Senior Citizens, is skeptical the drug companies will go along with the measure.

"I just don't think that they are prepared to give up the profits that the American market represents," he said.

Marvin said there are several ways for drug companies to get around the bill.

"One way is to clearly limit the amount of drugs going into Canada," Marvin said. "A second way is to require FDA (Food and Drug Administration) inspections of all the drugs being re-imported into this country, even though they are being made in this country."

Republican lawmakers defended the bill, saying they have closed as many loopholes as they possibly can.

"The drug companies don't like this bill, and the reason they don't like this bill is they think it's going to be effective," said Sen. Slade Gorton of Washington.

But Clinton Administration officials say the only way to guarantee seniors the relief they need is to allow them to band together under Medicare to negotiate with drug companies for the same kinds of discounts insurance companies and the Canadian government have.

Charlotte Walton says she's never understood why she and other seniors have paid so much more.

"It makes me angry, and I've heard a lot comments on it that other people feel the same way," she said. "Why can't we get it?