According to CNN, the search for contaminated blood pressure drugs continues even after initial recalls. These drugs, which are angiotensin II receptor blockers, have been found to contain a substance known as NDMA. While normally an ingredient in rocket fuel and pesticides, NDMA can also occur as a result of a chemical reaction. Manufacturing issues are thought to be the cause of this batch of recalls, which impacts millions of patients and involves drugs from many different companies.
NDMA is considered a genotoxin, which impacts DNA replication. Cancer is caused by rapidly replicating cells, so the concern is being exposed to a genotoxin can increase a person's cancer risk. The contaminated drugs are believed to have originated from Zhejiang Huahai Pharmaceuticals, a Chinese drug manufacturer. While investigations are ongoing, it's believed that during the processing of the active ingredient, a chemical reaction took place, which led to the presence of NDMA. There are also concerns about some of the practices at this manufacturing plant. For instance, officials say that certain materials were reused against best practices, which led to problems with processing and contamination.
While it's true the U.S. Food and Drug Administration does monitor drug manufacturers around the world, it can be difficult to identify contaminated drugs in some cases, as the FDA relies on manufacturers to have practices in place to identify impurities. In this case, the manufacturers failed to identify a problem and subsequently did not alert the FDA until the drugs were already being prescribed.
These blood pressure drugs have been prescribed to millions of people around the world. There is a concern that not all patients will be notified, which means they will continue to take the contaminated drug. While the risk of developing cancer is estimated to be quite small, that doesn't take away from the worry and concerns patients and families are currently experiencing.