The U.S. Food and Drug Administration is updating the public on the agency’s ongoing investigation surrounding the recent voluntary recalls of multiple generic angiotensin II receptor blocker (ARB) drug products used to treat high blood pressure and heart failure. Hetero Labs Ltd. in India has announced a recall of 87 lots of losartan potassium tablets (25 mg, 50 mg and 100 mg). The recalled losartan potassium tablets made by Hetero Labs and distributed by Camber Pharmaceuticals contain the impurity, N-Nitroso-N-methyl-4-aminobutyric acid (NMBA). The impurity is a known animal and potential human carcinogen. This is the first ARB recall resulting from the presence of NMBA, which is the third type of nitrosamine impurity detected in ARB medicines.

Recent testing of these recalled lots of losartan potassium tablets showed NMBA levels higher than the FDA’s interim acceptable intake limits. The FDA’s evaluation suggests that the nitrosamines found in ARBs may be generated when specific chemicals and reaction conditions are present in the manufacturing process of the drug’s API, and may also result from the reuse of materials, such as solvents.

Recent FDA analyses of NDMA and NDEA in recalled valsartan found that overall, the risk to individual patients is very low, although this doesn’t diminish the significance of this issue or the FDA’s concerns. The agency continues to evaluate the risks nitrosamines pose to patients. The FDA and drug manufacturers continue to test all ARBs for nitrosamine impurities. If NDEA, NDMA, NMBA, or other nitrosamine impurities are found in products at levels above the interim acceptable intake limits, the FDA will work with companies to swiftly remove affected products from the market.

Source: www.fda.gov