Common stomach medicines taken by millions of people around the world could be tainted with the same cancer-causing agent that sparked a global recall of blood pressure pills, health authorities have warned.
The substance has been found in some heartburn and ulcer medicines, including the brand-name drug Zantac and generic versions.
Preliminary tests have found low levels of the nitrosamine impurity N-nitrosodimethylamine (NDMA) in some ranitidine products, according to the US Food and Drug Administration.
Ranitidine, as the drug is known in generic form, is an antacid and antihistamine used to treat gastrointestinal disorders. NDMA is found in cooked or cured meats such as bacon, and is a common industrial by-product.
Health officials say anyone taking the drugs should contact their doctor.
“Drug impurities remain a major national concern,” said Dr David Robbins, associate chief of endoscopy at Lenox Hill Hospital in New York City. “While Zantac may prove safe in the long run, this latest statement adds confusion and concern, so my interim advice to patients is simple: switch to another drug … and, of course, confirm with your doctor the need for an antacid.”
In a statement, pharmaceutical giant Sanofi, which makes Zantac, said that it “takes patient safety seriously, and we are committed to working with the FDA. Zantac OTC has been around for over a decade and meets all the specified safety requirements for use in the OTC market.”
Zantac is made in Mexico and Sanofi sources its active ingredient from Spain, said company spokesperson Ashleigh Koss.
The discovery underscores the challenge facing pharmaceutical industry regulators in overseeing a vast global supply chain of drugs, drug ingredients and factory processes, The Age reports.
Dozens of versions of the hypertension treatment valsartan have been recalled since last year over fears they could be contaminated with NDMA. Many of those drugs were made in China or India, raising questions about the quality of generic manufacturing in some factories.
Bloomberg News reports that poor quality controls and efforts to conceal manufacturing problems from the FDA have complicated oversight of overseas drug producers.
Dr Janet Woodcock, director of the FDA’s Centre for Drug Evaluation and Research, said the FDA was working with international regulators and industry partners to find out where the contamination originated.
Alarm bells were sounded by Valisure, a Connecticut-based online pharmacy that tests all medications it dispenses. It detected high levels of NDMA in both generic and brand versions of Zantac sold at major pharmacies.
It filed a petition with the FDA seeking a recall of Zantac and its generics that contain NDMA. The FDA said the NDMA levels in the drugs were low, while Valisure’s petition labelled them excessive.
“We don’t think this poses an immediate hazard to human health, so we’ll have an ongoing process to determine whether recalls are needed,” Dr Woodcock said.
She expected it would several weeks to get more information.
Zantac and its generics are sold with and without a prescription in different strengths. Almost 25 million prescriptions for the drugs were written in 2018, according to Bloomberg Intelligence data.
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