Patients taking medication for high blood pressure may wonder if it is safe to take valsartan.

In July 2018, the U.S. Food and Drug Administration (FDA) recalled certain batches of valsartan because they were potentially contaminated with NDMA, a probable human carcinogen.

What Does Valsartan Do?

Valsartan is an angiotensin II receptor blocker (ARB) that works by preventing blood vessels from becoming too narrow. It is an antihypertensive drug often prescribed for the treatment of high blood pressure or heart failure. Valsartan may also lower the risk of dying after experiencing a heart attack, and may be prescribed to slow the progress of end stage kidney disease. More than 9 million people in the U.S. have a prescription for the drug.

Diovan, the brand-name form of valsartan, is made by Novartis International AG. It was not affected by NDMA contamination.

What Is NDMA?

NDMA is short for N-nitrosodimethylamine, a chemical that may increase the risk of cancer, according to the Environmental Protection Agency (EPA). NDMA is often a chemical byproduct of manufacturing processes, including those in tanneries, pesticide manufacturing plants, tire manufacturers, dye manufacturers, and fish processing facilities.

What Lab Tests Have Been Done on NDMA?

According to the EPA, NDMA has been found to cause complications such as tumors in the liver, respiratory tract, kidneys and blood vessels of mice and rats. Due to these test results, it is believed that NDMA may cause similar complications in humans.

How Would NDMA Get in Valsartan?

According to the FDA, a large Chinese generic drug manufacturer, Zhejiang Huahai Pharmaceutical Co. Ltd., instituted different manufacturing processes that allowed valsartan to become contaminated with NDMA. Since then, the FDA has identified other manufacturers that have been determined to produce NDMA-contaminated valsartan.

Much of the contaminated valsartan appears to stem from Zhejiang Huahai Pharmaceutical Co., but at least three drugs made by ten companies have been affected by the contamination.

According to Bloomberg, an FDA inspector who visited the Zhejiang Huahai Pharmaceutical factory in May 2017 discovered that some of the machinery was old, rusted, and in a state of disrepair. The inspector reported that customer complaints were often not followed up, and testing anomalies of the medications were not investigated or reported. Instead, the manufacturer allegedly left these test results out of official reports and falsified documents showing that the drugs had been tested and found to be free of impurities.

Other possible theories regarding how valsartan and other drugs came to be contaminated with NDMA include contamination caused by recycled solvents used during the manufacturing process, side reactions or byproducts of drug synthesis, or the breakdown of drug compounds over time. Additionally, the conditions under which the drugs are stored may have an effect on the level of NDMA found in them. The temperature that the medications are stored at may have an effect on the speed at which the drug compounds degrade or break down.

What Is the Risk Level Associated with Taking Contaminated Valsartan?

After the recall, the FDA said it is thankful that the cancer risk with contaminated valsartan is low. It is estimated that if 8,000 patients were taking the highest dose of NDMA-contaminated valsartan daily for four years, one additional case of cancer over their lifetimes could be diagnosed. A majority of patients take less than the 320 mcg maximum dosage, which means the cancer risk is lower than the FDA’s scenario. However, European health regulators estimate the risk is higher, at one out of every 3,390 patients.

Some of the valsartan that was tested contained 17 micrograms of NDMA per individual pill. As little as two grams of NDMA can result in death, and much smaller doses may still cause cancer or liver problems.

The FDA has said that based on its analysis of the amount of contaminants found in the medication, the potential exposure “appears to be small.” The FDA was not surprised by the contamination, as foreign manufacturing plants have different safety guidelines, but also noted that not all valsartan products were contaminated.

What is NDEA?

NDEA is short for N-Nitrosodiethylamine, which is a nitrosamine impurity very similar to NDMA and is also a probable human carcinogen. Some valsartan batches tested positive for trace amounts of NDEA.

What Else Might Expose Humans to NDMA and/or NDEA?

The chemicals NDMA and NDEA are known environmental contaminants found in meats, dairy products, vegetables, and water. NDMA is often found in tobacco smoke, and in smoked food products including smoked fish and meats. Still, the FDA does not accept the presence of either contaminant in medication.

What Is the FDA Doing to Ensure It’s Safe to Take Valsartan?

The FDA has developed three new testing methods to determine the presence of NDMA or NDEA in all angiotensin II receptor blockers. These tests are called the GC/MS headspace method, the combined headspace method, and the combined direct injection method.

These test can evaluate the presence of NDMA or NDEA in the active pharmaceutical ingredients and in the finished products.

How Long Were Contaminated Valsartan Drugs on the Market?

The contaminated lots of valsartan were available for an undetermined amount of time. They may have been on the market as long ago as 2012 when the manufacturing facility in China made a change to its production process that is believed to have been the source of the contamination. At this point, the factory switched to a different drug solvent. Although the new solvent was meant to make manufacturing more efficient and make it easier to control impurities, the change may have led to the valsartan contamination. During this time period, millions of people who believed it was safe to take valsartan may have been exposed to the carcinogen.

Not all lots of valsartan products were impacted, so before stopping your medication, check with your doctor.

The FDA said its investigation is ongoing and that it is constantly updating its lists of recalled medications.

Valsartan is not the only drug to have recently been found to be contaminated with NDMA. According to Chemical & Engineering News, many drugs have tested positive for the carcinogen over the past several years. Following the discovery of the NDMA contamination in valsartan in 2018, at least six other popular drugs have been found to contain the contaminant.

What Cancers Have Been Linked to NDMA and NDEA Contamination?

Cancer of the liver, kidneys, lungs and nasal cavity may be associated with exposure to the contaminants. In addition to cancer, NDMA may also cause damage to the liver, kidneys, and lungs. NDMA exposure may also result in side effects including jaundice, nausea, vomiting, fever, abdominal cramps, and dizziness.

Am I Eligible to File a Valsartan Lawsuit?

If you or a loved one thought it was safe to take valsartan, but developed certain cancers in 2015 or later, you could be eligible to participate in a valsartan lawsuit investigation.