Abstract

Background: We used electronic medical records (EMRs) to perform a comparative investigation of the pharmacotherapy outcomes in patients administered brand-name and generic glimepiride for treatment of diabetes mellitus.

Methods: We collected data on prescribed daily doses (PDD) and HbA1c levels of diabetes mellitus patients given metformin and glimepiride, but not pioglitazone for at least 6 months prior to October 13, 2012, after which glimepiride was replaced with generic drugs. The PDD/defined daily dose (DDD) ratio for glimepiride therapy and HbA1c levels before and after the replacement were compared.

Results: A total of 257 cases (128 males, 64.6 ± 12.0 years old) were included in the analysis. Of these, 33 (12.8%) remained unchanged in terms of antidiabetic drug dosage and/or the drugs administered, and 224 (87.2%) showed such changes after the glimepiride brand-name–generic drug switch. There was no significant difference in mean HbA1c levels measured before and after replacement. PDD/DDD ratios (3.1 ± 1.4) of glimepiride showed a significant increase in 224 cases, while PDD/DDD ratios in the aforementioned 33 cases remained 2.3 ± 1.1 before and after the medication switch.

Conclusion: Diabetic patients using generic glimepiride had similar HbA1c levels compared to patients using the brand-name drug. Nonetheless, the doses required up-titration, and the differing costeffectiveness should be evaluated and considered. EMR analysis for brand-name–generic drug switch studies is feasible and recommended, but it is important to rigorously ensure that the study method will not introduce confounding bias before enrolling patients.