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Nitrosamine impurities

TGA investigation – potential contamination of medicines with nitrosamine impurities

9 November 2021

The Therapeutic Goods Administration (TGA) has been investigating the issue of nitrosamine contamination of medicine since 2018. Information on affected medicines has previously been published (see ‘Related Safety alerts’). This page provides general information for consumers and health professionals.

Nitrosamines are a group of compounds that can damage DNA. They are commonly found in low levels in a variety of foods, including smoked and cured meats, dairy products, vegetables, in some drinking water and in air pollution.

Long-term exposure to nitrosamines, over years, can increase an individual's risk of developing cancer. However, the risk posed by nitrosamine impurities found in some medicines, at the concentrations identified to date, is considered to be very low. Regardless, the TGA has high standards for both the quality and safety of medicines and therefore, we are working with medicine sponsors to ensure these impurities are not present at unacceptable levels. The actual health risk depends on the medicine and dose taken, and will vary from person to person.

The TGA has published safety alerts for medicines affected by this issue, which provide information specific to users of those medicines (see ‘Related Safety alerts’).In general, consumers should be aware that there is no immediate health risk from this issue. This is because the levels of nitrosamine impurities detected in medicines supplied in Australia are very low.

A very conservative approach is used to set limits for these impurities. Consumers taking an affected medicine that contains nitrosamines at or below the acceptable daily intake limit are not expected to have an increased cancer risk, even if the medicine is taken over a lifetime.

You should not stop taking your medicines without first consulting a doctor or pharmacist about any concerns related to this issue. Suddenly stopping many medicines can pose a greater and more immediate risk to your health than potential contamination with nitrosamine compounds.

The TGA will keep the public informed as new information becomes available. When a medicine is investigated, not all brands may be affected, and even when there is a problem with a product, not all batches of that product may be affected.

If consumers have any other questions or concerns about this issue, they should speak to their health professional.

Please be aware of this potential issue and advise patients accordingly. You may wish to reassure patients that the risks posed by nitrosamines at the levels observed to date are considered very low. Please remind patients of the importance of taking their medicines as prescribed to manage their condition.

If a medicine batch is recalled due to nitrosamine impurities, pharmacists may be able to dispense a different batch or brand. Information for health professionals is provided in the individual recall notices for affected products in the TGA System for Australian Recall Actions database. Advise your affected patients of recalled medicines due to potential nitrosamine impurities.

To find out if a medicine is unavailable as a result of this issue, refer to the information about medicine shortages published on the TGA Medicine Shortage Reports Database. Prescribers should determine if there are appropriate alternative treatments for patients.

The TGA is working closely with other international regulators and medicine sponsors to investigate and address nitrosamine impurities in medicines. We have set acceptable daily intake limits for many nitrosamine impurities to ensure medicines remain both safe and of high quality. Medicines regulators use these limits to determine if regulatory actions are required for affected products.

There are a range of regulatory responses which can be used to manage this issue, including medicine recalls, suspending medicines, placing conditions on a product’s registration and/or actions related to product manufacture. When considering the appropriate regulatory response, the TGA also considers the impact on medicine availability.

Details of recall actions are available on the TGA System for Australian recall actions database. Safety advisories are published on the TGA website. Details of medicine shortages are published on the TGA Medicine Shortage Reports Database.

Updated information will be published on this issue as it becomes available.

N-nitrosodimethylamine (NDMA), and subsequently other nitrosamines, were first identified in July 2018 in blood pressure medicines known as ‘sartan’ medicines, which were manufactured using an active ingredient sourced from an overseas manufacturer. Later, other sartan medicines from the same manufacturer and from other manufacturers were found to be affected by nitrosamine impurities.

Several medicines have since been found to have unacceptable levels of nitrosamine impurities both in Australia and overseas. Medicines affected by nitrosamine impurities in Australia include ‘sartan’ blood pressure medicines in 2018, metformin products and ranitidine products in 2019, and varenicline products in 2021.

Consumers and health professionals can report problems with medicines or vaccines. The report will contribute to the TGA's product monitoring.

The TGA cannot give advice about an individual's medical condition. Consumers are strongly encouraged to talk with a health professional if they are concerned about a possible adverse event associated with a medicine or vaccine.