Novartis halts distribution of Zantac drug amid probe into impurities

Novartis AG's Sandoz unit said Wednesday it was halting distribution of its versions of the ranitidine drug known as Zantac in all its markets, including the United States and Canada, after contaminants were found in the heartburn drug.

The Swiss drugmaker's decision follows an investigation by U.S. and European regulators into the presence of the impurity, N-nitrosodimethylamine (NDMA), in the ranitidine drug and a distribution halt in Canada announced late Tuesday.

"Current evidence suggests that NDMA may be present in ranitidine, regardless of the manufacturer. As a result, and at Health Canada's request, companies marketing ranitidine products in Canada have stopped any further distribution until evidence is provided to demonstrate that they do not contain NDMA above acceptable levels," the regulator said. 

Health Canada said the stop distribution request is an interim precautionary measure as it gathers more information and consults with international health regulators.

Branded versions of the drug such as Sanofi SA's Zantac are available for over-the-counter (OTC) sale in Canada, while generic versions are available for sale both OTC and with prescription.

Precautionary measure

Over-the-counter ranitidine is approved to prevent and relieve heartburn associated with acid indigestion and sour stomach. The prescription versions are used to reduce stomach acid to prevent and treat conditions, such as heartburn, ulcers of the stomach and intestines, and gastroesophageal reflux disease or GERD, Health Canada said. 

A distribution halt is different from a recall and means that existing stock of the drugs in pharmacies or stores can still be sold.

NDMA is classified as a probable human carcinogen, meaning long-term exposure to levels above what is considered safe could increase the risk of cancer. 

Health Canada advised consumers:

• Talk to your doctor or pharmacist at your earliest convenience about alternative, non-ranitidine treatment options appropriate for your health circumstances. 
• Individuals taking a prescription ranitidine drug, including a recalled product, should not stop taking it unless they have spoken to their health-care provider and obtained alternative treatment, as the risk of not treating the condition may be greater than the risk related to NDMA exposure.

Similarly, neither the U.S. Food and Drug Administration nor the European Medicines Agency had asked patients to stop taking the drug when the regulators said last week they were reviewing the safety of ranitidine.

Novartis said in an emailed statement its step was precautionary and adequate measures "will be implemented in alignment with relevant health authorities as required."

Ranitidine works by blocking the action of acid-producing cells in the stomach. 

Last year, Health Canada announced recalls of some heart and high-blood pressure medications because of concerns surrounding the same impurity.