A Toronto woman says she peeled back the labels on her medication bottles and found other people’s prescriptions behind them.

Sarah Attwell says she noticed the labels were very thick after picking up her five prescriptions from a local Shoppers Drug Mart.

"When I investigated and pulled the labels off, I noticed they’re all used and I have other people's names, doses, medications and doctors,” she says.

Attwell says she’s concerned about what “residuals” might be in the bottles.

She’s also concerned for her privacy and the privacy of other patients. The man behind the counter at her pharmacy refused to discuss the matter with CTV Toronto on Friday.

Shoppers Drug Mart’s head office, however, issued a statement Friday saying it is concerned about Attwell’s discovery.

"Our first priority is to ensure that any patient who may have had their personal health information compromised is notified as soon as possible,” the company said.

“We will also take swift corrective action to determine how this could have occurred and will reinforce our standards of practice to ensure that this never happens again.”

Attwell has taken action already. She has filed a complaint with both the Ontario Privacy Commission and the Ontario College of Pharmacists.

Trell Huether, a privacy commission spokesperson, said a file has been opened and they are looking into the complaint.

The Ontario College of Pharmacists said that, while it’s too early to know what happened, possible punishments range from limits on a practice to outright suspension.

With a report from CTV Toronto’s Janice Golding