More generic versions of Zantac are being pulled from pharmacy shelves after officials discovered low levels of a probable carcinogen in the heartburn drug.
The Food and Drug Administration this week disclosed additional recalls of ranitidine medicines, which treat stomach acid and ulcers.
Concerns over a potential cancer risk stem from the presence of a likely carcinogen called NDMA, which has also prompted the recall of several versions of blood pressure-lowering pills.
Drugstore chains CVS and Walgreens have suspended sales of Zantac and various generic versions. A series of recalls have also taken place over the last few months.
In the latest batch announced this week, Denton Pharma and Appco Pharma issued voluntary recalls.
Denton, which does business as Northwind Pharmaceuticals, announced that it is recalling all of its 150-milligram and 300-milligram Ranitidine Tablets. The company said it had not received any reports of related "adverse events," which is medical terminology for illnesses, injuries or deaths. But it nonetheless advised consumers to immediately discontinue use and discard the medicine.
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Separately, Appco issued a voluntary recall for all of its 150-milligram and 300-milligram Ranitidine Hydrochloride Capsules. The company said it's not aware of any adverse events tied to the prescription drug but advised patients to stop taking it and seek advice from their physicians on potential alternative treatments.
In addition, pharmaceutical maker Mylan issued a voluntary recall for all of its 150-milligram and 300-milligram versions of ulcer and heartburn treatment Nizatidine Capsules after finding "trace amounts" of NDMA in the drug, which is made by Solara Active Pharma Sciences Limited.
Emery Pharma, an Alameda, California-based private lab, conducted an analysis on the stability of ranitidine and found the drug appears to form NDMA when exposed to heat. In a petition filed Jan. 2 with the FDA, Emery also requested the agency suspend sales of all ranitidine products.
Emery says the drug should be shipped in temperature-controlled vehicles and include a warning about potential risk if the drug is exposed to sustained heat when delivered.
Emery CEO Ron Najafi said he has served as an expert witness for people suing drug manufacturers over NDMA found on commonly-prescribed blood pressure medications.
"This product needs to be relabeled properly," said Najafi. "We found this molecule is temperature sensitive. That is really the bottom line. The more you heat it, the more NDMA you generate."
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This article originally appeared on USA TODAY: Generic versions of Zantac recalled over cancer scare