The Food and Drug Administration says traces of a potential carcinogen have been found in samples of the popular diabetes drug manufactured by Merck, the latest example in which the impurities were detected in best selling pharmaceutical products.
Millions of people with Type 2 diabetes rely on the drug, sitagliptin, to control high blood sugar. Merck markets the drug as Januvia and Janumet. Last year, sitagliptin generated more than $5 billion in sales for Merck and was its third best-selling product.
Despite the discovery of impurities in some batches of the drug, the FDA will temporarily allow Merck to continue selling the drug, considering the risks outweigh the immediate medical needs of the patient. “It may be dangerous for patients with this condition to stop using their sitagliptin without talking to their healthcare professional,” the agency said in a statement.
Merck, which first detected the contamination and reported it to regulators, said it was working to resolve the issue and would work with health authorities around the world. “We remain confident in the safety, efficacy, and quality of our sitagliptin-containing drugs,” the company said, adding that it did not anticipate the shortages that the FDA would face. approved for the first time in 2006.
The impurity, known as NTTP, belongs to the family of nitrosamine compounds that have been detected in a number of drugs in recent years. Since 2018, federal regulators have warned the public about nitrosamine contamination in samples of the heartburn drug Zantac, the antibiotic rifampin, and the smoking cessation drug Chantix.
The FDA has described NTTP as a “possibly carcinogenic to humans,” based largely on laboratory testing. The agency lacks data to directly assess the carcinogenic potential of NTTP and instead said it used information on a closely related compound to determine exposure limits. Scientists at the agency have set the lifetime exposure to nitrosamines in the drug at 37 nanograms per day, although it would allow up to 246 nanograms in sitagliptin at this time.
In its statement, the FDA called the additional cancer risk “minimal.”