In the late spring of 2018, reported valsartan contamination by N-nitrosodimethylamine (NDMA) was linked to Zhejiang Huahai Pharmaceuticals, a drug manufacturer out of China, by the European Medicines Agency (EMA). A public announcement was made by the European counterpart of the U.S. Food and Drug Administration (FDA) shortly afterwards.

Valsartan is a generic medication used to treat high blood pressure in children over age six and adults. It is also used to treat heart failure and as a prophylaxis to prevent re-occurrence of a heart attack in patients that have recently had one.

Valsartan is part of a group of high blood pressure medicines known as angiotensin II receptor agonists that work by dilating blood vessels and allowing blood to flow more freely.

Since the hypertensive drug is a generic and manufactured by several pharmaceutical companies, the valsartan contamination by NDMA did not affect all supplies of the drug. For those supplies that had been contaminated by NDMA, classified as a “probable human carcinogen,” the issue may have been going on for some time, according to reports.

Valsartan contamination may have been a contributing factor in several cases of patients that took the medication and later developed liver problems or cancerous conditions.

Because of the risks associated with NDMA valsartan contamination, pharmaceutical regulators in Europe and the United Kingdom (U.K.) started the recall process on medications that were potentially contaminated.

By July 2018, the FDA was reportedly starting to put pressure on three of several manufacturers of the generic drug by asking them to voluntarily recall valsartan from the American market.

Regulatory authorities in the U.K. identified that the likely source of the valsartan contamination by NDMA occurred in 2012 when changes were made in the manufacturing plant and processes. Not finding out about the valsartan contamination until six years later may have put thousands of people in danger.

Meanwhile, according to a recent article by NJ.com, it has been discovered that a second carcinogen known as N-Nitrosodimethylamine (NDEA)—also found in tobacco smoke—was found in three lots of valsartan drugs manufactured by Torrent Pharmaceuticals.

NDEA was found in several batches originated from Zhejiang Huahai Pharmaceuticals in China, as indicated by the FDA.

Despite this discovery, the FDA doesn’t recommend that any patient currently taking a valsartan drug quit taking it until they have seen their prescribing physician and found an alternative medicine.

The FDA is keeping track of which valsartan products have been recalled and which others have not. Physicians can find another hypertensive treatment options and pharmacists can switch to a valsartan version that has not been listed as problematic. The consequences for suddenly removing a medication from a drug regimen for cardiac conditions can be fatal–those on the drug should contact their physician and pharmacy with questions.