FDA finds carcinogen in some versions of popular diabetes drug

FDA said Wednesday it has found high levels of a potentially cancer-causing impurity in some versions of the diabetes drug metformin.

FDA said Wednesday it has found high levels of a potentially cancer-causing impurity in some versions of the diabetes drug metformin. According to agency spokesperson Sarah Peddicord, FDA detected N-Nitrosodimethylamine (NDMA)—which the World Health Organization classifies as a probable human carcinogen—in higher than acceptable amounts in some extended-release versions of metformin. The agency is contacting companies whose drugs had elevated NDMA levels. A person familiar with the matter says some recalls of the drug are expected as early as this week, although Peddicord said FDA "cannot confirm or deny a recall action before it has taken place." She said the agency "will continue to take quick and appropriate action when needed to protect American consumers." Peddicord said FDA has not found increased levels of NDMA in immediate-release metformin, and patients should not stop taking the diabetes drugs without talking to their health care provider first. FDA started investigating metformin late last year after some versions of the drug sold in other countries were found to contain NDMA; the agency said in February it had not detected excessive levels of NDMA. The Senate Finance Committee is set to hold a hearing next week to assess FDA's ability to adequately inspect drug-production facilities in other countries. A new report from the online pharmacy Valisure found that of 128 metformin samples sent in by people around the United States, 36% had NDMA levels that exceeded daily acceptable limits established by FDA. "The presence of this carcinogen in metformin where multiple tablets can be taken daily and often for a lifetime diabetic condition, makes this finding particularly concerning," said Deanna Akinbajo, chief pharmacist at Valisure. NDMA-related issues were also behind the recalls of all versions of ranitidine (Zantac) last month and millions of doses of angiotensin II receptor blockers beginning in July 2018