Millions of Americans take medication daily to control their blood pressure. We recently found that some generic versions of one medication, valsartan, contain an impurity that doesn’t meet FDA’s safety standards. Valsartan is an angiotensin II receptor blocker (ARB) that treats high blood pressure and heart failure. The FDA currently has a major operation underway to investigate and address this troubling finding. This investigation is led by a dedicated task force of experts focused solely on this important work. Their mandate is to oversee the investigation and track new developments and information coming in from valsartan manufacturers. This multidisciplinary team of chemists, toxicologists, medical doctors, pharmacists, investigators, communication specialists, and analytical lab staff coordinates across the FDA, and acts on the newest available information.
As our investigation continues to identify the root cause of this impurity, we want to take the opportunity to describe to the public what we are doing to find the cause of the impurity, to prevent a recurrence of this episode and to protect patients who need this medication.
On June 19, a U.S. manufacturer of valsartan products, Prinston Pharmaceuticals Inc., contacted the FDA‘s Center for Drug Evaluation and Research (CDER) about its products containing valsartan active pharmaceutical ingredient (API) manufactured by Zhejiang Huahai Pharmaceutical Co. (ZHP). Prinston informed CDER that they had stopped making valsartan products because ZHP had detected an impurity in the API – a chemical known as N-nitrosodimethylamine (NDMA). NDMA is a probable cancer-causing chemical found in trace amounts in water and some foods. However, the levels of NDMA in ZHP’s valsartan API – while still trace amounts – were unacceptable.
Although the risk to patients taking the affected products is extremely low, we take matters of pharmaceutical quality very seriously. We took immediate steps to address these findings.