Impact of Meropenem Shortage on Pseudomonas aeruginosa Susceptibility and Clostridioides difficile Infection Incidence Rate and Contributions of Pharmacists in 32 Rosai Hospitals Nationwide

This study investigated the effect of partial supply suspension of meropenem (MEPM), a key drug for the treatment of severe infections, to verify the impact of antibiotic shortages. This retrospective comparative study examined days of therapy (DOT) for anti-pseudomonal antibiotics and antibiotics for extended-spectrum β-lactamase-producing bacterial infections, drug susceptibility of Pseudomonas aeruginosa, incidence of Clostridioides difficile infection (CDI), and response to MEPM shortages for one year pre- and post-supply suspension in August 2022. The DOT for MEPM decreased in 23 out of 32 facilities (71.9％); there were regional differences. The DOT change rates of MEPM were negatively correlated with those of piperacillin/tazobactam between the pre- and post-MEPM shortage periods, in medical facilities in which alternative drugs to MEPM have been proposed. No significant changes were observed in the MEPM susceptibility rate of Pseudomonas aeruginosa (median, 1.7％; interquartile range, -0.1 – 4.2) and minimum inhibitory concentration or susceptibility to alternative drugs. In the group with insufficient MEPM supply, there was a significant decrease in healthcare facility-onset CDI. In the group where pharmacists took the lead in addressing the supply shortage of MEPM and in the group where decisions regarding MEPM replacement therapy were overseen by pharmacists, high susceptibility of P. aeruginosa was maintained, and HO-CDI decreased despite an increase in the DOT for alternative antibiotics. The shortage of antibiotics could present an opportunity to promote antimicrobial stewardship, recognizes and highlight the need for active intervention by pharmacists during antibiotic shortages.