FDA Clarifies Impurity Risks From ARB Recalls
Following last summer’s discovery of nitrosamine impurities in angiotensin II receptor blocker (ARB) drugs, which led to numerous recalls of the blood pressure drugs, the US Food and Drug Administration (FDA) on Wednesday walked back its initial risk estimates.“We initially estimated that if 8,000 people took the highest valsartan dose (320 mg) containing N-Nitrosodimethylamine (NDMA) from the recalled batches daily for four years, there may be one additional case of cancer over the lifetimes of those 8,000 people,” Janet Woodcock, director of FDA’s Center for Drug Evaluation and Research wrote. “In reality, the vast majority of patients exposed to NDMA through ARBs received much smaller amounts of the impurity than this worst-case scenario, and, since not all ARBs are affected, it’s very likely that a patient taking an ARB for four years would not have always received one of the affected products.”
She also noted that although FDA does not know the exact number of patients impacted by the ARB recalls, the agency has identified 43 ARBs that do not contain any nitrosamine impurities.
FDA is also working to see if other drugs manufactured in a similar way as the ARBs are seeing similar impurities. “Now that we know some of the root causes of the nitrosamine impurity problem, we’re using these findings to inform our evaluation of medicines other than ARBs,” Woodcock wrote.
She added that FDA continues to work with the European Medicines Agency, Health Canada and others, to understand the full scope of this issue.
“We share inspectional findings, laboratory testing methods and results, and our assessments of root cause and impact. We are working to incorporate what we have learned about the process risks that caused these impurities into our oversight of drug manufacturing, which includes how we assess applications and changes to applications, as well as enhancing our inspection coverage to evaluate the controls in place to prevent unacceptable levels of nitrosamine,” Woodcock added.
She also further explained how FDA placed Lantech Pharmaceuticals, a contract solvent recovery facility for valsartan active pharmaceutical ingredient (API) manufacturers, on import alert in June after it failed to perform an adequate investigation into a customer’s contaminated valsartan API.
FDA Statement