Trends and patterns of national antimicrobial consumption in Japan from 2004 to 2016

Frequent use of broad-spectrum antimicrobial classes has been reported in Japan; however, little is known about the long-term trend of national antimicrobial consumption, and that of individual agents. This study analyzed the national sales data of systemic antimicrobials from 2004 to 2016, derived from the IMS Japan Pharmaceutical Market database, to assess the consumption patterns of antimicrobial classes and agents in Japan. The number of defined daily doses per 1000 inhabitants per day (DID) was calculated for each antimicrobial agent. During the last 13 years, total antimicrobial consumption fluctuated by only 5% around the average of 14.41 DID. In 2016, the most used class was macrolides (32%), followed by cephalosporins (28%) and fluoroquinolones (19%). Oral agents comprised a large proportion (93%) of antimicrobial consumption. The most used agent, clarithromycin, accounted for 25% of all oral compounds used in 2016. The consumption of oral agents with high bioavailability, such as fluoroquinolones, amoxicillin, and sulfamethoxazole/trimethoprim increased, whereas that of cephalosporins decreased. In 2016, ceftriaxone was the most consumed parenteral agent, followed by cefazolin. The consumption of parenteral agents increased after 2009 when high-dose regimens of piperacillin/tazobactam, meropenem, and ampicillin/sulbactam were approved by the health insurance system. National antimicrobial consumption has been stable over the last 13 years. Moreover, shifts in the use of agents with high bioavailability and those approved for high-dose regimens were observed. However, the increased use of broad-spectrum agents is worrisome. A multifaceted approach is required to reduce overall antimicrobial consumption.