Formation of Nitroso-Omeprazole

Continuing the discussion from Anybody dealing with possible formation on Nitrosoimidazoles?:

Hi Everyone

Recently, I saw an interesting case in pharmacy. He was a middle-aged man was taking medicines such as Omeprazole, Aspirin, and Nitroglycerin at the same time. I was interested in investigating the interaction of these drug. Finally, I reached a chemical reaction that probably occurs between omeprazole and nitroglycerin and leads to the creation of Nitroso-omeprazole. Figure indicates the detailed mechanism and the pathway of nitroso-omeprazole formation. This reaction has been predicted and simulated using artificial intelligence. Is omeprazole (or other PPIs) at the risk of nitroso-forming?

Best Regards

Saleh Rakhshani


Do not forget that nitroglycerine undergoes reduction in the oral cavity as well as other parts of the body very fast to produce nitric oxide, which is the ultimate vasodialator. I know as I workd on nitric oxide donors in NCI in Larry Keefer’s team. So, the nitrosating agent could be generated by nitric oxide and oxygen or other oxidizing agrents in vitro.


Dear @SalehRakhshani Thanks for bringing interesting case forward. Good thought process

Before understanding chemistry. Just would like to understand following:

  1. Has the middle aged man suffered with any adverse reaction?
  2. What are the doses he was prescribed with?

I foresee even though taken as combination due to their metabolic pattern, the drug-drug interaction and their resulting N-nitroso omeprazole is tough to reach at toxic levels in body.


I want to add that N-nitroso omeprazole is not a nitrosamine of basic nitrogen. So it doesn’t form diazonium ions through activation. But it may be mutagenic.