The offending impurity is N-nitrosodimethylamine (NDMA), which has been listed as a probable carcinogen by the International Agency for Research on Cancer.
Health Canada announced Tuesday a major recall of drugs used for high blood pressure and heart failure because they may be contaminated with a probable human carcinogen.
Health Canada also advises anyone taking any medication containing valsartan to speak to their pharmacist to find out if their medicine is being recalled.
"Patients should not stop taking their medicine if it contains valsartan unless they've been specifically instructed to do so by their prescriber or pharmacist".
But the agency also said that anyone taking medication that contains valsartan should continue to take it unless told to stop by their doctor or pharmacist. The recall was issued after the Ministry's senior officials reviewed Ministerial Resolution No. (366) of 2010 governing the withdrawal, suspension, or prevention of distribution of pharmaceutical and medical products to protect public health.
As a result, valsartan medicines containing the active substance from Zhejiang Huahai are being recalled in the EU.
Valsartan is used to treat hypertension and can prevent cardiovascular complications associated with the condition.
EMA is now evaluating potential impact on patients of the exposure to NDMA in valsartan medicines.
In the United Kingdom, the Medicines and Healthcare products Regulatory Agency (MHRA) is working with pharmacies to recall the affected medicines but have also stated the importance of patients continuing their treatment but to seek advice from a healthcare professional immediately.