Nitrosamine formation via non-prescription drugs?

Both carcinogenic and non-carcinogenic nitrosamines can be formed under physiological conditions in the human body by a reaction between nitrite and secondary or tertiary amines. A large number of people are exposed daily through drinking water to high levels of nitrate, which can be reduced to nitrite. Moreover, nitrate and nitrite are present in vegetables and nitrite is used in food preservation. Dietary exposure to amines is normally below 100 mg per day, whereas paracetamol and antazolin, both secondary amines, are used therapeutically at much higher doses. Knowledge about the possible interactions between these widely used drugs and the background exposure to nitrite is presently not available. Therefore, an evaluation of the carcinogenic hazard related to this combination is needed.