Some drug management systems have been established in Japanese hospitals to reduce medical costs and regulate drug usage. Among the many available prescription drugs, antimicrobials should be given special attention because their inappropriate use often leads to sudden outbreaks of resistant bacteria. As drug specialists, pharmacists should monitor the use of all drugs, particularly antimicrobials. Carbapenems are a class of broad-spectrum antimicrobials that are widely used to treat infections worldwide. However, their inappropriate use has led to an increase in the incidence of drug-resistant bacteria and consequently, medical costs, at hospitals. To reduce inappropriate use and drug resistance, we have established a permission system to control the use of carbapenems at the Japanese Red Cross Nagoya Daiichi Hospital. In this study, we retrospectively evaluated the applicability of the new permission system compared to that of the notification system and the non control system for 14 months each. The two management systems were able to maintain total antibiotic use density and control the outbreak of drug-resistant bacteria (P. aeruginosa, E. coli, and K. pneumoniae). The number of carbapenem prescriptions was decreased dramatically when this permission system was enforced. Compared to the non control system, the cost of antimicrobials was reduced by $757,470 for the 14-month study period using the permission system. These results suggest that our system to control the use of antimicrobials can efficiently suppress the incidence of drug-resistant bacteria and medical costs at hospitals.

• Quantitative data - Quantitative data were used during the intervention

• Human - All activities regarding organisations and individuals involved in health products and services

• Healthcare delivery