An avalanche response and a glitch in insurance coverage have delayed plans for a bus trip to Canada so local senior citizens could buy less expensive prescription drugs.

Since the trip was announced two weeks ago, 500 people have called seeking a spot on the bus, with half of them from Ohio, said a spokesman for the sponsors -- the Washington, D.C.-based Alliance for Retired Americans and the United Steelworkers.

A bus was scheduled to leave Mercer County Monday morning for Hamilton, Ontario, and return on Tuesday.

Because of the deluge of requests, the groups are trying to get a second bus for Mercer County and to set up another trip from Ohio, the spokesman said. No date has been set for the trip from Mercer County and no firm plans are in place for a trip from Ohio, the spokesman said.

Also, the clinic in Hamilton, where seniors were to be examined by a doctor, was having difficulty obtaining insurance coverage for the event, said Marie Malagrecca, ARA's western Pennsylvania director. Canadian law requires a patient be examined by a licensed doctor in that country before a prescription can be filled by a Canadian pharmacy, she said.

Prescription drug prices in Canada are up to 60 percent lower than in the United States.

Martin Berger, president of the Pennsylvania ARA, said the trips allow Americans without prescription drug insurance to get a better deal on their pills.

But more importantly, he said, the group hopes the trips attract U.S. lawmakers' attention.

"People can save thousands and thousands of dollars by buying in Canada,'' Berger said.

U.S. pharmaceutical companies, which produce much of the world's prescription drug supply, say pricing pressures outside the United States force them to sell drugs in other countries at lower prices. They argue that if they are forced to sell drugs at those prices in the U.S. they could be ruined financially.

Both the Alliance for Retired Americans and the United Steelworkers said the delay will help seniors make sure they have proper identification when entering Canada and returning to the U.S. Security has increased since the Sept. 11 terrorist attacks. U.S. citizens must show their birth certificates and photo I.D. at the border.

For further information about the trips, call Beverly Colandrea, (724) 346-3537.