Levels of a carcinogenic impurity found in several brands of the high blood pressure and heart failure drugs containing the active ingredient valsartan are up to more than 2.5 times higher than what is considered “reasonably safe for human ingestion based on lifetime exposure,” according to a Food and Drug Administration (FDA) news release. The agency reported earlier that the impurity may have been present in some of the drugs for as long as four years.
The impurity is called N-nitrosodimethylamine or NDMA. For reference, the FDA says that consuming up to 0.096 micrograms (mcg) of NDMA per day is considered reasonably safe for human ingestion based on lifetime exposure. Valsartan-containing products tested by the FDA found that some manufacturers had tablets with anywhere from 0.3 mcg per tablet to as much as 20 mcg per tablet.
Despite this, the FDA says the risk of someone developing cancer from taking the tainted drugs is minimal. “FDA previously estimated that if 8,000 people took the highest valsartan dose (320 mg) containing NDMA from the recalled batches daily for four years, there may be one additional case of cancer over the lifetimes of the8,000 people,” the agency said in a news release. “That estimate was based on the highest daily dose, however many people may have taken lower doses, and therefore their risks would theoretically be less.”
In July, the FDA notified the public that several pills containing valsartan by various manufacturers were being recalled because they were found to be contaminated with an “unexpected impurity,” NDMA. The ingredient is considered possibly carcinogenic by the Environmental Protection Agency (EPA).
NDMA is an organic chemical byproduct of manufacturing and can unintendedly make its way into manufacturing through certain chemical reactions. Recalls of several drugs containing valsartan were issued, and the list continues to be updated as the FDA investigates this issue further.
In September, the FDA announced that it had identified a second possible cancer-causing impurity – identified as N-Nitrosodiethylamine, or NDEA, in some valsartan products. As a result, the recall was expanded.
FDA News Release