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

Shimatani Tomohiko

Inoue M.

Kuroiwa T.

Xu J.

Mieno H.

Tazuma S.

Digestive and Liver Disease

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.

Generic product

Intragastric pH

Omeprazole

Medical sciences [ 490 ]

eng

Elsevier

[ISSN] 1590-8658

[DOI] 10.1016/j.dld.2006.01.032

[PMID] 16524789

[NCID] AA11610665

[DOI] http://dx.doi.org/10.1016/j.dld.2006.01.032 isVersionOf