The same impurity that caused several blood pressure medication recalls last year is the source of another drug recall, this one involving a popular medication used to treat type-2 diabetes. The voluntary recall spans the entire United States and comes from Sun Pharmaceutical Industries, which found that some of its metformin hydrochloride extended-release medication (sold as RIOMET ER) may have unacceptably high levels of an impurity called n-nitrosodimethylamine (NDMA).
The recall was issued on September 23 and involves one lot of the RIOMET ER drug sold in 500mg/5ml dosage to consumers. Because NDMA is officially known as a ‘probable carcinogen’ in humans, the FDA limits how much of the impurity can be present in medication taken daily. In the case of this recall, the levels of the impurity were found to be higher than the FDA’s maximum Acceptable Daily Intake.
The contaminant itself is very difficult to avoid as it occurs naturally in the environment and is found in a variety of foods, as well as water. For this reason, the compound is found as an impurity in many medications, but it must be kept under a certain level in the US. Excessively high levels of NDMA have previously led to many blood pressure medication recalls.
Earlier this year, the FDA issued an advisory warning that many lots of metformin extended-release tablets contain NDMA levels that exceed its maximum daily intake limit. The agency urged recalls of the drugs in light of this information, stating that it had already reached out to five companies and that it would take steps to help prevent a metformin shortage in the nation should recalls take place.
In the case of this recall, Sun Pharmaceutical Industries is recalling a total of 747 cartons of the drug, which has the expiration date 10/2021 and the lot number AB06381. Patients taking this recalled medication are warned to continue taking the drug even if they have a recalled lot — the risk of stopping metformin is greater than the risk of exposure to this impurity, the recall notes. Rather, consumers should get in touch with their doctor to get a replacement prescription.