By Aaron Gould Sheinin, WebMD
Oct. 12, 2020 – The recall of extended-release metformin continues this month as 76 more lots have been flagged for a possible cancer-causing ingredient.
The FDA announced the latest 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.”