A pain medication is subject to a recall in Canada because of a packaging error.

The problem is that bottles from a lot of 2-milligram pms-Hydromorphone tablets from the company Pharmascience Inc. may include some stronger 8-milligram tablets.

Health Canada describes hydromorphone as an opioid "used to treat pain and opioid use disorder."

The agency warns that "accidentally taking too much," for example, an 8-milligram tablet instead of a 2-milligram tablet, "or suddenly increasing the dose of hydromorphone could potentially lead to an overdose, which can be life-threatening even in people who have some tolerance to opioids."

The 8-milligram and 2-milligram tablets look different (the 8 mg are white with the number 8 inscribed on one side; the 2 mg tablets are orange and inscribed with the number 2), but Health Canada says anyone with a product from the affected lot should stop using it and reach out to their pharmacists for a replacement nonetheless.

The recalled lot number is 639268. The bottles come with 100 tablets and an expiration date of January 31, 2026. The company reports the products were sold between May and August 2022.

"If you have accidentally taken the 8 mg hydromorphone tablet instead of the 2 mg hydromorphone tablet and you have any health concerns, or are unsure whether you have taken too much hydromorphone, contact your healthcare professional, hospital emergency department or regional poison control centre immediately, even if there are no symptoms," Health Canada writes online.

The complete details of the recall and a list of hydromorphone overdose symptoms are available online.