The Food and Drug Administration in the U.S. is warning of increasing theft and a growing black market in prescription and over the counter drugs, medical devices and infant formula.

"There have been several cases where patients experienced adverse reactions from stolen drugs, reactions that were most likely due to improper storage and handling," the FDA states in a letter to those involved in the drug supply chain.

Health Canada says black market medications pose a risk to Canadian consumers.

In a written statement to CBC News, the agency states, "Health Canada continually works with the Canada Border Services Agency to prevent importation of any unapproved or counterfeit drugs and natural health products."

It notes drugs and natural health products sold in Canada will have either an eight digit drug identification number, a natural product number or a homeopathic medicine number.

"These numbers indicate that the products have been assessed by Health Canada for safety, effectiveness and quality," said the statement.

The FDA says any product that has left the legitimate supply chain poses a potential safety risk to consumers.

The American agency is urging businesses in the warehouse, transportation and manufacturing sectors to review security practices to minimize the risk of cargo and warehouse theft.

"Your members need to be one-step ahead of thieves in securing their warehouses and product transport," FDA acting assistant commissioner for regulatory affairs, Michael Chappell wrote in a letter to industry representatives.

In order to protect the public the FDA proposes a market recall of products in the supply chain with the same lot numbers as stolen goods.

It also wants a prompt public notification system, which would make it harder for thieves to sell the stolen goods.

The agency has set up a website listing stolen goods and advising how to report thefts.