Cancer-causing chemicals called nitrosamines have been detected in the diabetes drugs Januvia and Janumet.

The pharmaceutical company Merck & Co, known as MSD in the UK – which manufactures Januvia and Janumet – has announced that the two diabetes medications will be decontaminated by the end of the year.

According to Merck & Co, the drugs were contaminated in the storage and manufacturing process.

In a bid to fix this issue, the pharma company has made significant changes to its quality control processes to prevent any further contamination.

The FDA have issued a statement stating: “To avoid a shortage and help ensure patients have access to an adequate supply of the medicine, FDA will not object to the temporary distribution of sitagliptin containing NTTP above the acceptable intake limit of 37 ng per day, and up to 246.7 ng per day”.

The MHRA which regulates medicines, medical devices and blood components for transfusion in the UK have been notified and are yet to comment.

Dr Kelly Johnson-Arbor said: “Nitrosamines are chemicals that are found in foods, cosmetics, and toys.

“Nitrosamines are also found in drinking water. Some nitrosamines may cause cancer when people are exposed to high amounts of them for a prolonged period of time.”

Individuals who have used nitrosamine-contaminated medications for a long period of time are more at risk of developing cancer compared to those who do not use these drugs, experts have said.

Fellow academic Professor Dr Adeel Khan noted: “As a class of organic compounds, nitrosamines have been in our consumptive diets for decades since they are used as food preservatives and curing agents for meats.

“Nitrosamines are found naturally as well as from man-made manufacturing and agricultural processes.”

Prior research has found that nitrosamines can trigger the development of colorectal cancer, lung cancer, esophageal cancer, kidney cancer, stomach cancer and liver cancer.

“In recent years, nitrosamines have been found in many prescription and over-the-counter medications including losartan, metformin, ranitidine, and varenicline,” said Dr Johnson-Arbor.

Professor Khan added: “At a molecular level, nitrosamines cause DNA damage through two processes, alkylation and adduct formation. Over the long run, the accumulation of DNA damage raises the risk for cancers.”

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