Recall Widens for Diabetes Drug Metformin

Aaron Gould Sheinin

October 13, 2020

Updated November 3, 2020 // Editor's note: This story has been updated with new recall information.

The recall of extended-release metformin continues as two more lots of the diabetes drug have been added to the recall list. 

Kansas City-based Nostrum Laboratories has issued a voluntary recall of two lots of Metformin HCl Extended Release Tablets, USP 750 mg. The addition of Nostrum's pills come as 76 more lots were flagged in October for a possible cancer-causing ingredient.

The FDA announced the previous recall, involving Marksans Pharma Limited and Sun Pharmaceutical Industries products, on Oct. 5. It involves the 500mg and 700mg tablets.

More than 175 different drug combinations have been recalled since late May.

Consumers can see all the recalled metformin products at this FDA website. The agency says that immediate-release metformin does not appear to have the same contamination problem.

The FDA has been investigating the presence of nitrosamines, known to be a possible carcinogen, in the popular diabetes medications since December, when it was first discovered in drugs in other countries. The agency said this month they still do not know the source of nitrosamines in the medications.

The investigation, and subsequent recalls, follows similar ones for contamination of popular heartburn and blood pressure drugs, also for nitrosamines, such as N-Nitrosodimethylamine (NDMA).

The FDA says patients taking metformin products that have been recalled should continue taking the medication until a doctor or pharmacist gives them a replacement or a different treatment option. It could be dangerous for patients with type 2 diabetes to stop taking the medication without first talking to their doctor.

The agency has asked drug manufacturers to test products before batches are released into the market. The companies must tell the FDA if any product shows levels of nitrosamines above the acceptable limit.

The risks from nitrosamines is not clear. The FDA says they may increase the risk of cancer in people who are exposed to high levels over a long period of time, "but we do not anticipate that shorter term exposure at levels above the acceptable intake limit would lead to an increase in the risk of cancer."

Sources "Questions and Answers: NDMA impurities in metformin products," "FDA Updates and Press Announcements on NDMA in Metformin," "Marksans Pharma Limited Issues Expansion of Voluntary Nationwide Recall of Metformin Hydrochloride Extended-Release Tablets, USP 500mg & 750mg, Due to the Detection of N-Nitrosodimethylamine (NDMA)."