[Nitrosamine formation via non-prescription drugs?]

Both carcinogenic and non-carcinogenic nitrosamines can be formed under physiological conditions in the human body as a reaction between nitrite and a secondary or tertiary amine. A major part of the population is exposed daily through drinking water to high levels of nitrate, which can be reduced to nitrite. Moreover, nitrate and nitrite are both present in vegetables and nitrite is used in food preservation. Dietary exposure to amines is normally well below 100 mg per day, whereas paracetamol and antazoline, 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.