David Poon, BSc Immunology and Infection, PharmD Student
It’s been in newspapers and on TV for over a week now. Valsartan is a common blood pressure medication used to treat high blood pressure and other heart-related diseases. On July 9, 2018, Health Canada announced that a potential cancer-causing impurity, known as N-nitrosodimethylamine, was found in batches of valsartan from 5 different drug companies whose main supplier for Valsartan was Zhejiang Huahai Pharmaceuticals in China: ACT, PRO DOC LIMITEE, SANDOZ, SIVEM, TEVA.1
NDMA is a toxic chemical found in a lot of different products, which may be of a surprise to you. In fact, there are many ways that NDMA may enter your body:2
- Ingestion of foods such as smoked or cured meats, including fish
- Drinking contaminated water, beer or whiskey
- Shampoo or other cleansers
- Inhalation of cigarette smoke or chemicals from the workplace such as tanneries, pesticide and rubber manufacturing plants
How it made its way into valsartan remains unknown. However, it’s believed that the contamination may have been a result of changes in the way valsartan was manufactured.3 What remains concerning for patients is, how long has this been going on for, what is the risk of cancer, and what should be done regarding this matter?
Will I Get Cancer?
“I don’t know.” This is probably the answer you’ll hear from most healthcare professionals. The truth is that we really don’t know. There are no clinical trials that will give us the answer to this question because you can’t ethically expose Person A to NDMA and Person B to placebo, and wait years to find out if Person A will get cancer or not.
What scientists do know is that NDMA exposure to mice can cause liver damage and kidney cancer.4,5 In human observational studies, NDMA has been shown to increase the risk of cancer, specifically colorectal and other stomach-related cancers.6,7,8,9
Now, before you panic, let’s take a step back and think about this logically. We mentioned that NDMA can be found in other foods and beverages, not just in these batches of valsartan. While we’re uncertain of the doses/strengths and lengths of NDMA exposure that will cause cancer, we do know that our risk of developing cancer increases with age due to environmental and genetic factors.
For instance, every time we step in the sun, we put ourselves at risk of developing skin cancer. To prevent skin cancer, do we stay indoors all day? No. We put on sunscreen and other protective clothing and enjoy the outdoors. The same can be said about the valsartan recall. Should you panic and stop taking valsartan and every other medication? No, because that in itself can lead to disastrous impact on your health.
The Bottom Line: What Should I Do Now?
The valsartan recall and sensationalization of it in the media can frighten anyone, especially when we hear that it may cause cancer. If you or any loved ones have been taking valsartan, there are steps that can be taken to minimize potential risks and complications.
- Keep taking valsartan to treat your medical condition, unless you’ve been told otherwise by a healthcare professional. The risk of stopping valsartan is likely greater than the risk of developing cancer.
- Speak to your pharmacist to see if the valsartan that you’ve been taking has been affected by the Health Canada recall.
- If affected, speak to your primary healthcare provider about other treatment options.
We hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at email@example.com with your feedback. We’d love to hear from you.
- Government of Canada, Health Canada. (2018, July 10). Several drugs containing valsartan being recalled due to contamination with a potential carcinogen. Retrieved from http://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2018/67202a-eng.php
- United States Environmental Protection Agency. (2014, January). Technical Fact Sheet – N-Nitroso-dimethylamine (NDMA). Retrieved from https://www.epa.gov/sites/production/files/2014-03/documents/ffrrofactsheet_contaminant_ndma_january2014_final.pdf
- Kaplan, S. (2018, July 16). Blood Pressure Medicine Is Recalled. Retrieved from https://www.nytimes.com/2018/07/16/health/fda-blood-pressure-valsartan.html
- Shamsi, A., Ahmed, A., & Bano, B. (2017). Structural transition of kidney cystatin in dimethylnitrosamine-induced renal cancer in rats: Identification as a novel biomarker for kidney cancer and prognosis. J Biomol Struct Dyn,35(5), 1020-1029. doi:10.1080/07391102.2016.1166988
- Cui, J., Guo, X. M., Bao, H. L., & Tan, J. B. (2016). Relationship between N-nitrosodimethylamine and risk of digestive tract cancers: A Meta analysis based on cohort studies. Zhonghua Liu Xing Bing Xue Za Zhi,37(5), 725-729. doi:10.3760/cma.j.issn.0254-6450.2016.05.029
- Song, P., Wu, L., & Guan, W. (2015). Dietary Nitrates, Nitrites, and Nitrosamines Intake and the Risk of Gastric Cancer: A Meta-Analysis. Nutrients,7(12), 1st ser., 9872-9895. doi:10.3390/nu7125505
- George, J., Rao, K. R., Stern, R., & Chandrakasan, G. (2001). Dimethylnitrosamine-induced liver injury in rats: The early deposition of collagen. Toxicology,156(2-3), 129-138. doi:10.1016/S0300-483X(00)00352-8
- Zhu, Y., Wang, P. P., Zhou, J., Green, R., Sun, Z., Roebothan, B., . . . Mclaughlin, J. R. (2014). Dietary N-nitroso compounds and risk of colorectal cancer: A case-control study in Newfoundland and Labrador and Ontario, Canada. Br J Nutr,111(6), 1109-1117. doi:10.1017/S0007114513003462
- Loh, Y. H., Jakszyn, P., Luben, R. N., Mulligan, A. A., Mitrou, P. N., & Khaw, K. T. (2011). N-Nitroso compounds and cancer incidence: The European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk Study. Am J Clin Nutr,93(5), 1053-1061. doi:10.3945/ajcn.111.012377