Objective: The use of generic drugs is promoted for the purpose of reductions of medical costs and patient’s copayment.  In general, it is thought that clinical effects of the original brand and the generic drugs are equal if they are bioequivalent.  However, it is necessary to inspect their therapeutic equivalence to use the generic drugs securely.  We, therefore, assessed the therapeutic equivalence and pharmacoeconomics by substitution of an original drug (Amaryl®) with a generic drug (Glimepiride [Tanabe]).
Methods: Therapeutic Equivalence: The total variation was calculated by using the HbA1c levels before it switched from Amaryl® to Glimepiride [Tanabe].  The tolerance limits were set as 1/4 of the total variation.  Pharmacoeconomics: The difference of drug prices and the difference of patient’s copayment were calculated.
Results: As the variation of HbA1c levels was within tolerance limits before and after switching from Amaryl® to Glimepiride [Tanabe], we evaluated that their therapeutic effect was equivalent.  The difference of drug prices after switching from the original to the generic one was 4,582.6 yen/year on average (minimum: 949.0 yen, maximum: 12,045.0 yen); the difference of patient’s copayment was 872.5 yen/year on average (minimum: 0 yen, maximum: 3,613.5 yen).  These data show that the use of the generic drugs is effective to reduce medical costs.
Conclusion: For further promoting the use of the generic drugs, we consider it essential to compare the therapeutic equivalence and the safety of the original and the generic drugs in clinical practice.

In recent years, the problem of antimicrobial resistance (AMR) from inappropriate use of antimicrobial drugs has emerged, and a plan to counter AMR has been formulated. From October 2017, our hospital started interventions to guide prescribing physicians in the proper use of intravenous antibiotics for patients requiring said treatment for more than 15 days. In the present study, we investigated the status of treatment with intravenous antibiotics and considered the effects of intervention. This study targeted a total of 2627 patients, 1971 of whom were hospitalized, who started using intravenous antibiotics from June 2017 to January 2018. We assigned those who started between June and September 2017 to the pre-intervention group and those who started between October 2017 and January 2018 to the post-intervention group. The number of patients using long-term intravenous antibiotics, total number of days of treatment, antimicrobial use density (AUD), day of therapy (DOT), and rate of use by lineage of antibiotics were compared. The number of patients using long-term intravenous antibiotics decreased to 40 in the pre-intervention group and 31 in the post-intervention group. There was no significant difference in the total number of treatment days, which was 5.1 ± 5.5 days before and 4.8 ± 4 9 days after, in the intervention group. The AUD of penicillin antibiotics increased and that of aminoglycosides decreased. Furthermore, the DOT of third-generation cephems and lincomycin decreased. Penicillin had an increased lineage use ratio, while that for thirdgeneration cephems, carbapenems, and lincomycin decreased. The number of patients using long-term intravenous antibiotics as well third-generation cephem and carbapenem antibiotics, which are broad spectrum antibiotics, decreased; the overall use of penicillin, a narrow-spectrum antimicrobial, increased. This suggested that the intervention resulted in the promotion of proper use of antimicrobial drugs.