Review of the in vitro microbiological activity of mecillinam against common uropathogens in uncomplicated urinary tract infection (uUTI): focus on resistant pathogens

Antimicrobial resistance in uropathogens commonly causing urinary tract infections (UTIs) is a growing problem internationally. Pivmecillinam, the oral prodrug of mecillinam, has been used for over 40 years, primarily in Northern Europe and Canada. It is recommended in several countries as a first-line agent for the treatment of uncomplicated UTIs (uUTIs) and is now approved in the United States (US). We performed a structured literature search to review the available evidence on susceptibility of common uUTI-causing uropathogens to mecillinam. Among 38 studies included in this literature review, susceptibility rates for Escherichia coli (E. coli) to mecillinam – including resistant phenotypes such as extended-spectrum β-lactamase–producing E. coli – exceed 90% in most studies. High rates of susceptibility were also reported among many other uropathogens including Klebsiella spp., Enterobacter spp., and Citrobacter spp. In the current prescribing climate within the US, pivmecillinam represents a viable first-line treatment option for patients with uUTI.