More trouble for valsartan with discovery of fourth carcinogen

Now a fourth potential carcinogen is being linked to the popular blood pressure medication valsartan. FDA has been informed that a solvent called dimethylformamide (DMF) was discovered in valsartan made by several companies, including Novartis. DMF is classified by the World Health Organization as a probable carcinogen.

The findings could complicate the agency's efforts to pull tainted products from pharmacies while informing doctors and patients which products are safe.

Recalls for valsartan as well as losartan, irbesartan, and combination medications have been ongoing since FDA began an investigation into the foreign manufacturing process for active pharmaceutical ingredients (APIs) in these drugs, causing impurities in the form of N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), which are suspected human carcinogens.

FDA’s investigation started back in June 2018, when the agency was informed that Prinston Pharmaceuticals had stopped manufacturing valsartan products because it had detected trace amounts of NDMA in valsartan API supplied by the Chinese manufacturer Zhejiang Huahai Pharmaceutical (ZHP) Co. FDA put ZHP on import alert, blocking all API from legally entering the United States. Another supplier of tainted valsartan API was identified in India.

As of March 1, the presence of a third carcinogen, N-nitroso-N-methyl-4-aminobutyric acid (NMBA), was found in lots of losartan potassium (25 mg, 50 mg, and 100 mg) made by Hetero Labs in India and distributed by Camber Pharmaceuticals.

The suspected presence of now a fourth carcinogen seems to have prompted U.S. lawmakers to seek out more information on FDA’s capability to protect the nation’s prescription drug supply. In general, factories in China and India make and supply API to worldwide drug companies that sell generics.