Cancer-Causing Contamination of Common Medications Continues

Nitrosamines are impurities found in some cured meats, vegetables and medications. These impurities could cause cancer if consumed in certain quantities over a long period of time. This could be the case for individuals regularly taking contaminated prescription drugs.

Nitrosamines were recently found in two common tuberculosis drugs: rifampin and rifapentine. The Food and Drug Administration (FDA) has recognized the dangers of such impurities and is investigating the recent contamination.

Life-Saving Tuberculosis Drugs Contaminated

The FDA confirmed nitrosamine contamination of rifampin and rifapentine at the end of August. The drugs are life-saving medications for those diagnosed with tuberculosis.

They may also treat other serious conditions and infections. Rifampin may treat leprosy and brucellosis, both rare infections.

Sanofi sells rifapentine in the United States under the brand name Priftin. Rifapentine currently has no approved or marketed generic products in the United States. This is according to Jeremy Kahn, an FDA spokesperson.

Note: Consumers have already filed lawsuits over nitrosamine-contaminated drugs. Learn more about your legal options by clicking on the appropriate link below:

Are All Nitrosamines Carcinogenic?

Nitrosamine compounds differ. Research has identified some compounds as potential or probable carcinogens.

carcinogen is a substance capable of causing cancer in a living thing.

Recently, some versions of blood pressure, heartburn and diabetes medications have been contaminated with potential carcinogens. This includes valsartan, losartan, Zantac, other ranitidine products and metformin. Any drugs deemed to be unsafe have been recalled by the manufacturers.

The compounds found in the tuberculosis drugs are not identical to those in other contaminated drugs:

  • Nitrosamines do exist at low levels in a variety of common products, such as water and some foods. If consumed at low levels, they may not pose a risk to human health. However, elevated levels of exposure over long periods of time can lead to cancer. The compounds found in the other medications are NDMA (N-nitrosodimethylamine) and NDEA (N-nitrosodiethylamine).
  • The compound found in the tuberculosis drugs is MNP and CPNP (1-methyl-4-nitrosopiperazine and 1-cyclopentyl-4-nitrosopiperazine). MNP was found in brand-name and generic forms of rifampin.
Learn about the cancer risk from NDMA-contaminated Zantac

Drugmakers Response to Contaminated Tuberculosis Medicine

Some drug manufacturers have addressed the health risk of contaminated tuberculosis drugs. For example, Mylan NV recalled more than 19,000 rifampin vials in October. The recall referenced the elevated levels of impurities.

Early data indicates around 8,920 reported cases of tuberculosis in 2019 in the United States. This data is from the Centers for Disease Control and Prevention (CDC). 

Tuberculosis can be deadly, and many patients require medication. Stopping drug sales could result in a shortage. As a result, some sales of rifampin have continued.

FDA Response to Contaminated Tuberculosis Medicine

The FDA is allowing sales to continue for these tuberculosis medications. It has advised consumers to continue taking their prescribed medications for now. Patients should also discuss any concerns with their physician.

The FDA requested the removal of other drugs contaminated by nitrosamines. For example, the FDA requested the removal of ranitidine products from the market in April 2020. It is possible rifapentine and rifampin will face official recalls after further investigation.

FDA Pushes for Removal of Nitrosamines from the U.S. Drug Market

On September 1, 2020, the FDA released Control of Nitrosamine Impurities in Human Drugs. The guide provides recommendations for identifying and preventing nitrosamines in drugs.

The FDA released the guide without prior public comment for immediate implementation. The guide includes information on:

  • The background of nitrosamine impurities and their presence on drugs
  • Acceptable intake limits
  • Recommendations for API manufacturers
  • Recommendations for drug product manufacturers
  • Maintaining the drug supply
  • When and how to report changes to the FDA
  • Additional resources

Ensuring that drugs are safe, effective and high-quality is a critical part of FDA's mission.

FDA Statement: FDA Provides Guidance to Industry for Detecting and Preventing Nitrosamines in Drugs

The FDA noted its goal to "remove drugs with unacceptable nitrosamine impurities from the U.S. drug supply." It also references proactive efforts to stop unsafe levels of impurities from the start of production.

Individuals who have taken potentially contaminated drugs should be proactive. They should discuss concerns with their physician.

If diagnosed with cancer or another serious illness, individuals may be eligible for a personal injury lawsuit. Speak with a lawyer about your case today by filling out the appropriate form below:

Free Zantac Lawsuit Consultation
Free Valsartan Lawsuit Consultation

Authored by Katy Moncivais, Ph.D.Medical Editor
Photo of Katy Moncivais, Ph.D.
Katy Moncivais holds a Ph.D. in Biomedical Engineering from The University of Texas at Austin. She’s an experienced Regenerative Medicine Consultant with a demonstrated history of working in the hospital & healthcare industry. Skilled in adult stem cells, medical devices, biomechanics, bacterial and mammalian cell culture, and regenerative medicine, she provides guidance on an array of topics affecting consumers. In her role at, Dr. Moncivais works alongside the writing and research staff to help deliver fact-based news stories to consumers. Her unique professional history alongside her rigorous educational background allows her to contribute to a variety of consumer-focused topics with a fresh perspective. In addition, Dr. Moncivais reviews portions of medically driven content to ensure scientific accuracy.
Editorial Standards Full Bio