Makers of sartan angiotensin II receptor blocker medications have been given a two year deadline to ensure their products are not contaminated with potentially carcinogenic N-nitroso impurities.

Following a 2018 scare in the US when the FDA found several generic ARB medicines contained nitrosamine impurities the Therapeutic Goods Administration has told Australian suppliers that they will have to implement rigorous testing of their products.

Concerns centre around the possible contamination during manufacture with small amounts of substances such as N-nitrosodimethylamine (NDMA), that are probable human carcinogens.

In the US, the FDA has issued recall notices for more than 40 sartan generic products, many manufactured in countries such as India and China. In Australia there have been two recalls of valsartan-containing products (APO-Valsartan, Dilart and Dilart HCT).

The TGA is requiring Australian suppliers of sartans to take a close look at the manufacturing process and assess whether there is any risk of contamination with N‑nitroso compounds.

Companies will also be required to conduct laboratory tests on their products to assess their level of nitroso impurities.

Regulators have stressed that there is no immediate risk to patients and that the potential cancer risk only applies to people consuming significant levels of nitroso compounds over a long period.

Meanwhile the TGA has also announced that the nitroso impurity problem may also extend to the anti-acid drug ranitidine. In a safety advisory it said the risk was likely to be very low, but until safe levels were verified patients should be advised to consider alternative acid suppressants.