Intended for healthcare professionals

Research Article

Intragastric bacterial activity and nitrosation before, during, and after treatment with omeprazole.

Br Med J (Clin Res Ed) 1984; 289 doi: (Published 22 September 1984) Cite this as: Br Med J (Clin Res Ed) 1984;289:717
  1. B K Sharma,
  2. I A Santana,
  3. E C Wood,
  4. R P Walt,
  5. M Pereira,
  6. P Noone,
  7. P L Smith,
  8. C L Walters,
  9. R E Pounder


    Ten healthy volunteers were studied before, during, and after treatment with omeprazole 30 mg daily for two weeks. On the 14th night mean nocturnal (2100-0700) intragastric acidity was significantly decreased by 75% (p less than 0.001). At 0700, 22 hours after the last dose of omeprazole, there were significant increases in the bacterial count and the nitrite and N-nitrosamine concentrations in the gastric juice (p less than 0.001). Three days later these changes had resolved. Short term treatment of healthy volunteers with omeprazole is associated with a short lived increase in the gastric bacterial flora, with endogenous production of N-nitroso compounds.