Several drugs that contain the ingredient valsartan used to treat heart failure and high blood pressure are already under voluntary recall since July because of an impurity.
Laboratory tests showed that the products are contaminated with N-nitrosodimethylamine, or NDMA, which the US Environmental Protection Agency considers as a possible carcinogen.
In a statement released on Thursday, the FDA said that another impurity has been found in three lots of recalled valsartan drugs produced by Torrent Pharmaceuticals.
The detected contaminant is a substance known as N-Nitrosodiethylamine, or NDEA, which is also classified as a possible carcinogen.
The unintentional contamination may have occurred through certain chemical reactions during the manufacturing process of the active substance.
FDA and the European Medicines Agency learned that Zhejiang Huahai Pharmaceuticals discovered NDEA in several batches of its valsartan, prompting a retest of recalled drugs and those that are currently available in the market.
“Our scientists are testing these products to better understand these impurities and to ensure they’re not present in other products,” FDA Commissioner Scott Gottlieb said in a statement.
“We’re also taking steps to make sure we’re providing stringent oversight of manufacturing processes to reduce the likelihood that impurities could be introduced into other products.”
EMA said that it is investigating the impact of NDEA detected in the valsartan produced by Zhejiang Huahai.
“Data on levels of NDEA are currently very limited, and EMA will provide further information on whether its presence impacts the risk assessment once more information becomes available,” EMA said.
FDA also assured that it continues to test valsartan-containing products for NDEA and related impurities. If it finds NDEA in products that have not been recalled, the agency said that it will work with companies to ensure that these are removed from the market.
FDA is also evaluating the risks posed by the substance in the affected products to patients. The agency said that it expects to complete the risk analysis in the coming days.
Amid widespread recall, the FDA reminded patients who take valsartan from a recalled lot to continue taking their current medication until a doctor or pharmacists provides them with a different treatment option or replacement. Patients who take valsartan from a recalled lot were also urged to speak to their pharmacist or doctor the soonest possible time.
FDA said that not all valsartan products contain NDEA or NDMA so pharmacists may be able to dispense those that are not affected by the recall.