We evaluated the effects of the cefazolin shortage on the supply, costs, and appropriate use of antimicrobials. We revealed the confusion brought to the antimicrobial market and the damage done to the appropriate use of antimicrobials. We also clarified the issue of maintaining a sustainable supply of antimicrobials.
Temporal changes in DID values clearly showed that the shortage of one antimicrobial brought confusion to the antimicrobial market. First, a halt to the manufacture of cefazolin was announced on February 28 by the pharmaceutical company with the largest share of cefazolin sales in Japan, and production ended in early March. However, the cefazolin DID values decreased from April to May. Most Japanese hospitals buy drugs through wholesalers; therefore, wholesalers’ stockpiles might have resulted in this lag. Meanwhile, the total antimicrobial DID values increased from March to April, which was 1 month before the decline in the manufacture of cefazolin. This suggested that the increase in total antimicrobial sales was not brought by the cefazolin shortage itself, but by information provided on the coming shortage. The information resulted in hospitals stocking up on antimicrobials. From this perspective, action by the Ministry of Health, Labour and Welfare of Japan was later than when stocking up took place. This highlighted the importance of early recognition and the need for structures for an appropriate governmental response when a shortage occurs. The government, companies, and hospitals need to maintain a close connection, and exchange information with each other. Also, frameworks for avoiding reckless purchasing by hospitals and to secure the proper distribution of medical resources are needed.
The cefazolin shortage also affected DID values of other antimicrobials. The actual DID values of the government-recommended alternatives ceftriaxone, flomoxef, clindamycin, and cefotiam were higher than their predicted DID values. It was suggested that drug makers increased the production of these drugs to alleviate damage caused by the cefazolin shortage; however, the production increases were insufficient to compensate for the cefazolin shortage, which led to secondary shortages among these drugs . According to a questionnaire-based study, the cefazolin shortage caused considerable damage in the maintenance of quality-assured medicines in various hospitals . Furthermore, antimicrobial surveillance in Japan in 2017 showed that 5 drugs—ceftriaxone, cefazolin, ampicillin/sulbactam, piperacillin/tazobactam, and meropenem—accounted for 59.2% of total parenteral antimicrobial sales . Increases in DID values among non-government-recommended alternatives, such as piperacillin/tazobactam and meropenem, may be explained by the extra production capacity that was brought about by their superiority in the market. Comparison by AWaRe group between actual and predicted DID values showed a decrease in “Access” antimicrobials and an increase in “Watch” antimicrobials. This means more broad-spectrum antimicrobials were used than narrow-spectrum ones because of the cefazolin shortage, meaning that the shortage appeared to harm appropriate antimicrobial use.
Since materials of domestically used antimicrobials depend on imports from China or India, it is difficult to improve the vulnerability of the supply chain by domestic measures alone [23, 24]. Currently, problems in antimicrobial factories in China or India have caused critical damage to the supply chain in developed countries; these are similar issues irrespective of the country. Likewise, this cefazolin shortage was caused by a Chinese government requirement pertaining to environmental protection and a temporary order to stop factories. From a short-range view, it is important to secure multiple antimicrobial resources for risk management to maintain a sustainable antimicrobial supply. From a long-range view, developed countries may need to develop domestic production of antimicrobial resources, but this requires support at the national or international level.
Despite the cefazolin shortage, the cost of antimicrobials per sales barely changed. This is thought to be because most antimicrobials used in Japan are generic drugs, and thus the cost differences between cefazolin and alternative drugs were small. Moreover, another important reason is that a cefazolin price increase did not occur because the reimbursement price of drugs is fixed by the government. Price setting is an important tool for securing the economy of medicine. However, reimbursement prices of drugs are gradually reduced year by year, which reduces the profit margins of pharmaceutical companies, especially for older drugs. This trend was accelerated by a recent increase in production costs;[4, 25, 26] cefazolin is also in the same situation. Low profits disrupt the production of affordable drugs and may lead to quality deterioration due to loss of investment. To maintain the stable production of essential medicines, the government should determine the appropriate drug price to sufficiently maintain companies’ investments. In the development of new antimicrobials, delinking profits and sales, for example, through government purchasing of drugs or/and the adoption of a subscription model, is desirable from a long-term perspective.
Our study has several limitations. First, because sales data can only clarify product circulation, the actual usage of antimicrobials was not assessed in this study. Different approaches such as the use of claims data or/and hospital data are needed to evaluate the prognosis of patients and changes in bacterial resistance patterns. Second, we created models based on past antimicrobial sales using a SARIMA model, and the models did not include unspecific events. The most important unspecific events are the emergence of endemic contagious diseases; nevertheless, no specific contagious diseases, including SARS-CoV-2 became endemic during the study period .