The year 2020 saw huge numbers of metformin products being removed from shelves due to contamination concerns. Metformin is an antidiabetic agents used to treat type 2 diabetes mellitus, and comes as immediate-release and extended-release products.
In May 2020, the US Food and Drug Administration (FDA) announced that it had recommended certain extended-release metformin products to be removed from shelves, as they were contaminated with N-nitrosodimethylamine (NDMA), a potential carcinogen. This followed a December 2019 announcement that the FDA was aware of there being low levels of NDMA in metformin products outside of the US. Lab studies showed NDMA in US products in February, although the FDA only recommended voluntary recalls of metformin products on May 28. Participating in the recall of extended-release metformin were five companies, of which one, Apotex and Amneal, recalled all of its lots.
Whilst NDMA is ubiquitous in daily life, found in cured and grilled foods as well as contaminated water, the daily limit was set at 96ng, specifically because such a dose would lead to a 1 in 100 000 increase in cancer risk after 70 years of exposure.
Prompted by a report from a private laboratory stating that 16 of 38 metformin products tested exceeded the daily NDMA limit, the FDA released its own article in the journal American Association of Pharmaceutical Scientists, stating the reasoning behind its recommendation for voluntary recall. The FDA noted that its own testing only found eight products of the 38 exceeded the NDMA limit, and explained that N,N-dimethylformamide (DMF) conflated levels in mass spectrometry measurements.
However, this was followed in July by an additional set of recalls, and yet more in August and October. Separately, Sun Pharmaceuticals issued a recall for its relatively new extended-release oral suspension (brand name Riomet ER; 500 mg/5 mL) which had only received approval in February.However, none of the FDA’s recalls have extended to immediate-release metformin, which is the most commonly prescribed form of the drug.
Source: MedPage Today
