EpiPen injectors, which are relied on by people with life-threatening anaphylactic allergies, are in "very limited supply" and Canadian pharmacies are to run out of adult doses in "coming days or weeks," according to a statement from Health Canada.

Pfizer Canada has been reporting shortages for months due to manufacturing delays, and today told Health Canada it won't have new stock of the 0.3 mg adult dose of epinephrine until the end of August.

"We understand and regret the challenges this situation continues to pose to patients," the company said in a statement.

Pfizer said inventory management can be challenging, in part because of the EpiPen's short shelf life, and it's not unusual for stock to be on backorder.

"Stock that was scheduled to be shipped in early August is currently being inspected which has caused a delay," the company wrote in an email to CBC News.

Health Canada said that while some pharmacies might have some inventory on hand now, it will likely be gone soon.

"We are exploring every option available to the department with the goal of resolving the situation as soon as possible," said the regulator.

Manufacturers say inventory management can be challenging, in part because of the EpiPen's short shelf life. (Rich Pedroncelli/Associated Press)

Limited availability of EpiPen Jr.

Pfizer Canada says it is currently able to provide the 0.15 mg EpiPen Jr., but supply is limited and the epinephrine injector for children is being carefully managed across the country.

EpiPen and EpiPen Jr. are used to deliver an emergency shot of epinephrine to patients who are at risk or have a history of the life-threatening allergic reaction anaphylaxis.

There are no alternative auto-injectors available in Canada.

EpiPen products expire on the last day of the month indicated on the package, so those with an August expiry date are good until Aug. 31.

Health Canada says anyone who has an anaphylactic reaction but has only an expired EpiPen should use the expired product and immediately call 911.

With files from Nicole Ireland and The Canadian Press

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