Health Canada is warning diabetics not to take certain medication not approved for sale in Canada because it can cause serious side-effects, including life-threatening hypoglycemia.

Consumers should avoid taking Xiaokeshuping Jiangtangning Jiaonang, because it contains the undeclared drugs phenformin, rosiglitazone and glibenclamide, the federal agency said on Wednesday. Phenformin was removed from the market in Canada in 1977, while the other two drugs should only be taken under the supervision of a health-care professional.

The federal agency warns that users may experience symptoms of serious hypoglycemia that include sweating, nausea, trembling, headaches and blurred vision. In severe cases, hypoglycemia may cause seizures and comas.

Health Canada has not authorized the products for sale. The federal agency notes travellers may have brought the pills into the country or consumers may have purchased them online.

Consumers should stop using the product and are advised to consult a doctor with any concerns.

Foreign product alert