A battle between one of the region's biggest drug stores and one of the biggest insurance companies will affect customers in Atlantic Canada as early as next week.

Most Shoppers Drug Mart stores will no longer accept Medavie Blue Cross cards at their pharmacies beginning next Monday.

The dispute is over how much Blue Cross is willing to pay pharmacies to help cover the cost of prescription drugs.

"Unfortunately, these pharmacies have not been able to reach a fair agreement with Medavie Blue Cross which ensures their ability to continue to deliver the level of service their patients expect," Tammy Smitham, director of communications with Shoppers Drug Mart, said Tuesday.

"Therefore, without a contract, Mediavie Blue Cross will not process electronic claims and, therefore, we can no longer accept those cards at those stores for payment."

Anyone who has a Blue Cross drug plan can still have their prescriptions filled at Shoppers Drug Mart, but they will have to pay the full cost up front and be reimbursed later by Blue Cross.

But Mike Randall, of Medavie Blue Cross in Moncton, said people should be cautious about doing that.

"The one caution is without that agreement in place there's nothing that says Shoppers couldn't charge more, and that would be more than your plan allows for and you might be out of pocket [for] expenses permanently," he said.

Blue Cross is recommending people switch to a drug store chain that will accept their card.

At least one independent pharmacy has already been fielding calls from Shoppers Drug Mart customers.

Anatasia Hanias, pharmacist/owner of The Medicine Shoppe in Halifax, said Blue Cross is such a big player in the region that she had little choice but to sign on, even if it means taking a loss on some drugs.

"Well, I'm hoping I get some customers that can't go to Shoppers anymore," she said.

Despite months of failed discussions between Shoppers and Blue Cross, Randall said there's still hope a deal can be reached.