The Use of Topical Antibiotics Based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data in 2017

The national action plan on antimicrobial resistance (AMR) in Japan emphasizes the importance of understanding antimicrobial use (AMU). Some studies have been conducted on oral and parenteral AMU in Japan. However, there are few studies on the use of topical antimicrobials, such as in dermatology and ophthalmology. Therefore, the purpose of this study was to investigate the use of topical AMU in Japan. Data on AMU in dermatology and ophthalmology were obtained from the 2017 National Database of Health Insurance Claims and Specific Health Checkups of Japan Open Data. The number of dermatological products used was 58,396,530 in 2017. The proportions of betamethasone/gentamicin and gentamicin used were 50.5% and 16.7%, respectively, whereas that of the ingredient quantity in gentamicin was 7.8%. It has been suggested that topical AMU should be evaluated based on the number of products being used. The number of ophthalmological products used was 24,655,653 in 2017, and the proportion of quinolones used was 95.9%. The high prescription rate of quinolones may cause an increase in quinolone resistance in the ophthalmologic field. Topical AMU, which is a potential "blind spot" in the measures against AMR, needs to be continuously monitored, together with systemic AMU.