New York CNN Business  — 

Shares of Walgreens, CVS and Rite Aid dropped Wednesday following a report that Amazon is considering opening brick-and-mortar pharmacies in the United States.

Walgreens (WBA) dropped 4%, CVS (CVS) fell 2% and Rite Aid (RAD) was off 3% during mid-morning trading.

Business Insider reported early Wednesday that Amazon is eying opening physical stores in a “handful” of locations, including Boston and Phoenix, and that there were discussions about putting pharmacies inside Amazon-owned Whole Foods stores.

“There is not a concrete plan” to open stores “and the talks are mostly exploratory,” Business Insider said. “Any meaningful rollout of stores could take more than a year.”

Amazon did not immediately respond to a request for comment from CNN Business.

Pharmacy chains in recent years have been under pressure as foot traffic to stores slows in favor of online ordering and reimbursement rates for prescription drugs decline.

At the same time, Amazon has expanded its pharmacy and health care presence.

In 2018, Amazon bought Pillpack, an online pharmacy that delivers medications to consumers. Last year, Amazon launched a pharmacy counter on its website to sell and ship common prescription drugs to customers. Amazon Pharmacy accepts most major insurance with the ability to manage orders on its website, and Prime members can get free two-day delivery.