The FDA previously found low levels of NDMA in tested metformin that it said did not necessitate recalls. (FDA).
After the FDA identified a likely carcinogen in samples of the broadly used diabetes med metformin, recalls appeared likely. Now it’s official.
The FDA said Thursday it had asked five metformin manufacturers to pull their extended-release metformin products, after pushing recalls of heartburn med Zantac and “sartan” blood pressure drugs for the same reason. A likely human carcinogen, N-Nitrosodimethylamine (NDMA), was discovered in samples of all three.
The FDA said it was working with drugmakers to determine whether the recommended recalls would cause a shortage in the U.S. The move doesn’t apply to metformin’s immediate-release formulation, and the FDA specified that “there are additional manufacturers of the metformin ER formulation that supply a significant portion of the U.S. market, and their products are not being recalled.”
The recall announcement comes just hours after the FDA declined to say whether it would pursue voluntary recalls after discovering NDMA contamination in tests metformin samples.
In February, the FDA said that its lab testing found low levels of NDMA in sample lots of metformin and didn’t recommend voluntary withdrawals despite anecdotal evidence of contaminated samples.
But in March, the independent testing laboratory Valisure disputed the FDA’s findings, saying it had discovered NDMA contamination at unacceptable levels in 42% of the batches it checked.
In a Public Citizen petition (PDF), Valisure asked for an immediate recall of the contaminated products it identified and contended the situation was likely to get worse as COVID-19 wreaks havoc on supply chains.
Valisure said it had tested 38 batches of metformin from 22 companies and found 16 batches from 11 companies had NDMA exceeding the FDA’s acceptable daily level of 96 ng. The laboratory found several batches that contained levels 10 times the daily acceptable intake limit.
It also found “significant variability from batch to batch, even within a single company,” which it says in its petition underscores the need for expanded testing of some drugs at the batch level. It asked another testing lab, Emery Pharma, to check its findings and Emery came to the same conclusions, Valisure said.
May 29, 2020