Acid-suppressive effects of generic omeprazole: comparison of three brands of generic omeprazole with original omeprazole.

BACKGROUND: Generic omeprazole contains the same active ingredient as original omeprazole and require verification of the bioequivalence with original omeprazole. However, very few clinical studies have been reported. AIMS: A prospective, randomised, open-label, crossover study to compare acid-suppressive effect of generic omeprazole with that of original omeprazole.
SUBJECTS: Seven healthy Helicobacter pylori-negative subjects of CYP2C19 extensive metaboliser.
METHODS: Intragastric pH was measured for 24 h without medications (placebo) and on day 7 of repeated administration of 10 mg once daily after breakfast of original omeprazole, Omeprazon, or three brands of generic omeprazole, Omeprazole-Towa, Ovulanze or Omerap.
RESULTS: Median values of intragastric pH and percentages of time with pH>4 for 24 h were significantly higher with administration of any omeprazole formulation compared with placebo (P<0.05, Wilcoxon signed-rank test). Whereas, during the night-time period (20:00-08:00 h), percentages of time with pH>4 with Omeprazole-Towa and Omerap were not significantly higher than placebo. Compared with Omeprazon, these two parameters for 24 h showed significantly greater inter-subject variations with Omeprazole-Towa (P<0.05 and P<0.01, F-test) and Ovulanze (P<0.05).
CONCLUSIONS: Acid-suppressive effects of some brands of generic omeprazole are not the same as original omeprazole. These differences might be reflected in clinical outcomes.

RCT Entities:   Population Interventions Outcomes