The online pharmacy that first warned that batches of ranitidine, the active ingredient in the heartburn drug Zantac and generics, contained a probable human carcinogen known as NDMA, is sounding the alarm again. The pharmacy, Valisure, says it has found the same potentially cancer-causing impurity in metformin, the first-line treatment used to control high blood sugar in adults and adolescents with type 2 diabetes.
Valisure conducted an analysis of 38 batches of metformin from 22 companies and found that 16 batches from 11 of them contained NDMA at levels above 96 nanograms, what federal authorities consider to be the daily acceptable intake limit. Several batches tested contained more than 10 times the daily acceptable intake limit, and the amount of the probable carcinogen appeared to vary from batch to batch, even within a single company, the company said in a news release.
Valisure filed a Citizen Petition with the Food and Drug Administration (FDA) on March 2, urging the agency to request recalls on lots of metformin where the probable cancer-causing impurity was detected.
“The carcinogenic nature of nitrosamines, and specifically NDMA, has been extensively studied by the scientific community since the 1960s,” the company said. “The World Health Organization and the International Agency for Research on Cancer have classified NDMA as a Group 2A compound thereby defining it as ‘probably carcinogenic to humans.’ FDA currently recognizes the danger of this compound and, as a result, as set strict daily acceptable intake limits and advised companies to recall medications like valsartan, losartan and ranitidine that did not meet this standard.”
In July 2018, NDMA was detected in several blood pressure and heart failure medications containing valsartan, which led to numerous recalls. Testing later identified NDMA in a similar heart drug, lorsartan.
Last fall, testing by Valisure uncovered high amounts of NDMA in ranitidine, the active ingredient in Zantac, which led to recalls of numerous prescription and over-the-counter ranitidine medications.
Valisure first alerted to the potential of NDMA contamination in metformin after an individual client requested the company test a sample of metformin.
“During testing of the medication sample of metformin, we used our standard testing process, which includes screening medications for the presence of the probable carcinogen N-Nitrosodimethylamine (NDMA), implicated in the global recalls of hypertension medications and most recently ranitidine. In this particular sample, we identified the presence of NDMA at higher than acceptable daily limits,” said Kaury Kucera, PhD, Chief Scientific Officer of Valisure.
“This finding prompted us to conduct a broader sweep of companies selling metformin. We found this was not an isolated incident and that there are many batches that contain unacceptable levels of NDMA. These findings underscore the importance of chemically validating all batches of medications for safety and quality.”
Valisure sent samples from a contaminated batch of metformin to be independently verified by an FDA-registered/inspected laboratory. The lab confirmed Valisure’s findings of many times higher than the FDA acceptable daily intake limit of NDMA for the retested batch.
“The contamination in these batches of metformin appears to be similar to the issues that continue to plague blood pressure medications like valsartan and losartan. Valisure urges FDA and industry to take swift and broad action to clean up the U.S. supply of metformin, a drug that tens of millions of Americans rely on. We must strive to avoid a repeat of over year-long rolling recalls that patients and practitioners still endure with blood pressure medications,” said David Light, Founder and CEO of Valisure.
“Valisure’s results indicate that contaminated batches of drugs are scattered and intermixed with clean ones throughout the American pharmaceutical supply chain,” he said. “This strongly suggests that neither the limited testing FDA is able to conduct nor the pharmaceutical companies’ self-reporting of analytical results is sufficient to protect American consumers from potentially dangerous contamination in the U.S. drug supply. Independent, third-party analysis of medication taken direct from pharmacy supply is needed more than ever.”
Beasley Allen attorney Frank Woodson is actively investigating potential claims of NDMA involving regular Zantac/ranitidine use that may have led to cancer of the stomach, colon, intestines, kidneys, bladder or pancreas. If you or a loved one may have been affected, please contact us.