Health Tips

Once in a while, you may see news regarding medications being recalled or pulled back from the market because they contain certain impurities/contaminants, which may pose health risks to the patients. 

The product recall of losartan, a blood pressure medication, took place in the year 2019 because some of the batches contained NDMA, a carcinogen. Source: malaysiakini

A medication for gastric pain called ranitidine was recalled in the year 2019 for containing excessive amounts of NDMA as well. Source: The Star

Metformin, a medication for diabetes, was pulled back from the market in the U.S. The affected metformin products were not sold in Malaysia. Source: The Wall Street Journal

Have you ever wondered what those impurities are about, and how they may affect your health? In this article, we shed light on nitrosamine impurities in medications.

What’s nitrosamine?

Nitrosamine is a type of contaminant, and is all around us. We’re exposed to it in many ways, but the main sources tend to be tobacco, cured and grilled meats such as bacon, fermented foods such as beer and cheese, shampoo and cleansers, and detergents and pesticides. N-Nitrosodimethylamine, or NDMA, is one of the nitrosamine compounds, and it can also be found in drinking water as a by-product of anion-exchange treatment of water. 

Nitrosamine is generally regarded to be carcinogenic, i.e. can cause cancer. Nevertheless, small amounts of exposure are not considered to be harmful.The US Food and Drug Administration (FDA) limits the amount of the NDMA in a daily dose of medication to 96 ng. If medications contain levels of nitrosamines above the 96ng, FDA recommends these drugs be recalled by the manufacturer as appropriate. In Malaysia, the National Pharmaceutical Regulatory Agency (NPRA) will be the one who handles the product recall.

How does nitrosamine end up in my medications?

Your medication contains not only the active ingredient, which is the substance that treats your medical condition, but it also contains other ingredients (called excipients) that form parts of the product. It’s not the medication that is harmful, but rather the contaminant present in the product (i.e. nitrosamine) that is causing the harm. 

There are multiple reasons why nitrosamines can be present in your medications. FDA found the source of nitrosamines can be related to the drug’s manufacturing process or its chemical structure or even the conditions in which they are stored or packaged. As foods and drugs are processed in the body, nitrosamines can also be formed. 

Why didn’t the authorities catch this problem before the medication is sold in the public?

You may wonder why there seem to be more medication recalls in recent years, and why the issues weren’t detected by the authorities before releasing into the market. Well, one of the reasons is that the authorities (worldwide and local) have better testing methods than ever before, thanks to improved technology. Trace amounts of impurities may have always been present in various products and medications previously, but we’re now getting better at detecting them. As the investigations and testing continues, along with the investigations done by other drug regulatory agencies, we may find low levels of nitrosamines in additional medications.

Photo by National Cancer Institute on Unsplash

How worried should I be? 

FDA does not expect nitrosamines to cause harm when ingested at low levels. Nitrosamine impurities may increase the risk of cancer if people are exposed to them at above acceptable levels and over long periods of time, but a person taking a medication that contains nitrosamines at, or below, the acceptable daily intake limits every day for 70 years is not expected to have an increased risk of cancer. In other words, you don’t have to be too anxious about nitrosamine impurities in your medications, as most of them should contain negligible levels to pose tangible cancer risks to you.

Should I continue taking my medications?

You should continue taking the medications your doctor prescribes to you. If you are worried about nitrosamine impurities in your medications, or wonder if the medications are one of the recalled batches, consult your doctor or pharmacist. It would be dangerous if you stop taking your medications without informing your prescriber, as the progression of your disease would probably do more harm to your health than the nitrosamines in the medications.

To check the recent product recall, you may visit this page or contact the National Pharmaceutical Regulatory Agency (NPRA) at +603-7883 5400 for further information. The press release or news regarding medication recall usually mentions the name, brand and batch number of the affected medications, which you can find on the packaging of your medications.

A word from DOC2US

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References

1. FDA - Information about Nitrosamine Impurities in Medications

2. FDA - Questions and Answers: NDMA impurities in ranitidine (commonly known as Zantac)

3. FDA  - Rigorous Detection of Nitrosamine Contaminants in Metformin Products: Balancing Product Safety and Product Accessibility

4. C&en - NDMA, a contaminant found in multiple drugs, has industry seeking sources and solutions

5. JAMA Network - Ranitidine’s N-nitrosodimethylamine Problem May be Tip of the Iceberg

Specific references were linked in its relevant part of the article. 

Cover image credit: Photo by Brett Jordan on Unsplash

Written by

Ms Joyce Toh