FDA: Contaminated Losartan Must Remain on US Market to Maintain Adequate Access to Patients

Despite the presence of potentially carcinogenic substances, the US Food and Drug Administration has announced that it will allow some manufacturers to continue to distribute losartan to ensure adequate access to the drug until it is safe to use. an impurity free stockpile is available later this year.

In one declaration issued on March 20, 2019, the Agency stated that losartan contained N-nitroso-N-methyl-4-aminobutyric acid (NMBA) concentrations exceeding the interim acceptable intake limit of 0.96 ppm, but below at 9.82 ppm, an adequate supply of losartan while companies obtain approval for manufacturing processes producing losartan without nitrosamine for patients. NMBA is known to be an animal carcinogen and possibly a human being.

According to the release, the agency "expects many companies to be able to manufacture losartan without nitrosamine impurities and replenish the US supply in about 6 months". He adds that FDA scientists "badessed the risk of exposure to NMBA at levels above 9.82 ppm and determined that there was no significant difference in cancer risk over a period of time. 6 months compared to a lifetime exposure to a NMBA at 0.96 ppm.

Last summer, the FDA announced for the first time that contaminated angiotensin receptor antagonists contained nitrosamine impurities that did not meet the agency's safety standards.

This announcement was followed by a burst of remember in July to remove valsartan products contaminated with N-Nitrosodimethylamine (NDMA). In August, the list of products of valsartan concerned has been expanded. Another nitrosamine, N-Nitrosodiethylamine (NDEA), was first identified in irbesartan tablets and then in additional drugs containing valsartan. This week, just one day before the FDA announces that it would allow the contaminated losartan of some manufacturers to remain on the market, Legacy Pharmaceutical Packaging, LLC, issued a voluntary recall losartan tablets of 40 repackaged batches due to detection of NMBA traces.

The FDA announced that it would determine, on a case-by-case basis, which lots of NMBAs containing losartan exceeding the 0.96 ppm limit would be released for distribution.