Drug regulators in South Korea have suspended sales of nearly three dozen metformin products contaminated with N-Nitrosodimethylamine (NDMA), a probable human carcinogen.
According to the Yonhap News Agency, South Korea’s Ministry of Food and Drug Safety, 31 of 254 metformin products recently tested were found to contain NDMA in excess of the management standards.The agency suspects that contamination may have occurred in the manufacturing process of finished drugs, not raw drugs.
“There is little risk to the human body even if over-detected drugs are taken for a long time, so the use of prescribed medications should not be arbitrarily stopped without consultation,” the Ministry said in a statement issued on Tuesday.
Nevertheless, the agency temporarily banned sales of the concerning metformin products and ordered doctors not to prescribes the affected drugs
Metformin is the most widely used oral treatment for Type 2 diabetes in the world, and is available as both a single ingredient medication and as a component of several combination drugs. Metformin is also included on the World Health Organization’s List of essential medicines, the safest and most effective medicines needed in a health system.
Late last year, however, the discovery of NDMA in some tablets prompted regulators in Singapore to recall six metformin lots. Similar metformin recalls have since been announced in Canada.
The U.S. Food & Drug Administration (FDA) began its own investigation in the wake of the Singapore metformin recalls. While those tests did find NDMA in some samples, the agency maintained that the levels detected were far below its recommended daily limit 96 nanograms. As a result, the FDA did not conduct any metformin recalls in the United States.
This past March, however, the online Valisure announced that its own testing had detected excessive levels of NDMA in 16 of 38 metformin samples. The highest levels were found in Amneal Pharmaceutical’s metformin, which in some cases contained as much as 16-times the FDA’s recommended daily limits. Several companies’ metformin contained more than 10 times the limit.
Valisure has since petitioned the FDA for a metformin recall and requested that the agency investigate how NDMA came to contaminate the medications.
NDMA is an environmental contaminant that can occur as a byproduct of certain manufacturing processes. The chemical has been declared a “probable human carcinogen” by the U.S. Environmental Protection Agency based on animal experiments that suggest exposure may increase the risk of cancer, including kidney, gastrointestinal, liver and breast cancers.