WASHINGTON -- Some lots of the antacid drug , the FDA said Friday morning.
NDMA is one of the potentially carcinogenic chemicals that previously forced some beginning last year.
Ranitidine, an H2 histamine inhibitor, is sold in both prescription and over-the-counter (OTC) forms primarily to relieve gastroesophageal reflux and for gastric and intestinal ulcer prevention. The FDA didn't indicate which particular products were affected since they are not being recalled at this time.
"The agency is working with international regulators and industry partners to determine the source of this impurity in ranitidine," the FDA's announcement said. "The agency is examining levels of NDMA in ranitidine and evaluating any possible risk to patients."
Although no recall was ordered, the FDA said patients using OTC ranitidine "could consider using other OTC medicines approved for their condition. There are multiple drugs on the market that are approved for the same or similar uses as ranitidine."
Patients taking prescription ranitidine who wish to switch to another medication should consult their physicians, the FDA said.
Contamination with NDMA and related nitrosamine compounds has been a vexing problem for drugmakers and the FDA since July 2018, when NDMA was found in certain Chinese-made valsartan products. The recalls later extended to other ARBs including losartan and irbesartan. Certain manufacturing processes were thought to be responsible and the agency has been working with manufacturers to avoid introduction of nitrosamines into these agents.
The FDA has consistently downplayed the actual risk to patients from the contamination, however, citing analyses that showed minimal if any increase in cancer risk. Nevertheless, into the summer of 2019.
In announcing the ranitidine contamination, the FDA said it was still evaluating the level of risk to patients. It did not indicate whether other H2 inhibitors may have the same problem.