The maker of the EpiPen says its adult-dose auto-injector will be in "very limited" supply in Canadian pharmacies in August and new stock likely won't be available until the end of that month.

Pfizer Canada says it is currently able to provide 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.

Pfizer informed Health Canada that the current shortage is due to a manufacturing issue with the EpiPen 0.3-mg format.

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.