Millions of antidepressant pills have been urgently pulled from shelves across America after they were found to contain cancer-causing chemicals.

The FDA declared that tens of thousands of bottles of duloxetine were recalled earlier this month after finding that they contained dangerously high levels of N-nitroso-duloxetine.

Dailymail.co.uk reports: The chemical is an impurity that occurs in the drug, which is sold under brand name Cymbalta, during manufacturing. However, it’s part of a group of chemicals called nitrosamines, which are used in pesticides and rocket fuel.

N-nitroso-duloxetine has been linked to a higher risk of cancer.

Patients are being urged to consult with their doctors before stopping the drug due to the risk of side effects.

Cymbalta is a selective serotonin reuptake inhibitor (SSRI), has been prescribed to about 18million Americans for depression, anxiety, and nerve pain.

The recall includes 20-milligram tablets in 500-count bottles manufactured by Towa Pharmaceutical Europe, which is based in Spain. 

No illnesses have been reported. However, patients concerned about the presence of N-nitroso-duloxetine are being urged to speak with their doctors before quitting the medications.

This is because suddenly stopping an SSRI causes a sudden stop in levels of the hormone serotonin. As the body doesn’t have enough time to adjust, patients could suffer withdrawal symptoms like mood swings, aches, pains, chills, and fatigue.

The FDA gave the recall a ‘Class II’ designation, which means that the products could lead to ‘temporary or medically reversible adverse health consequences’ but not serious health issues or death. 

N-nitroso-duloxetine belongs to a group of chemicals called nitrosamines, which are commonly found in water and food products. 

However, in higher concentrations and with long-term exposure, nitrosamines may increase the risk of throat, stomach, lung, brain, kidney, and bladder cancers.

The FDA said in a statement: ‘There are multiple reasons why nitrosamines can be present in drugs. 

‘FDA found the source of nitrosamines can be related to the drug’s manufacturing process or its chemical structure or even the conditions in which they are stored or packaged

‘As foods and drugs are processed in the body, nitrosamines can also be formed. FDA continues to test and research possible sources for drugs found to contain nitrosamines.’

It’s unclear exactly how much N-nitroso-duloxetine the affected capsules contained.

The FDA said that patients taking prescription medications with ‘potential nitrosamine impurities’ should speak with their doctor before stopping the medications.