Temocillin: A Narrative Review of Its Clinical Reappraisal.

Background: The emergence of multidrug-resistant Gram-negative bacteria, particularly extended-spectrum β-lactamase (ESBL) and AmpC-producing Enterobacterales, has brought renewed interest in temocillin, a narrow-spectrum β-lactam antibiotic first introduced in the 1980s. Objectives: We aimed to provide a comprehensive overview of the microbiological, pharmacological, and clinical profile of temocillin. Methods: We conducted a narrative review of the literature using the PubMed database to identify relevant studies concerning the microbiology, pharmacokinetics, pharmacodynamics, clinical applications, and safety of temocillin. Results: Temocillin shows strong in vitro activity against ESBL- and AmpC-producing organisms, and partial efficacy against certain Klebsiella pneumoniae carbapenemase (KPC)-producing strains. Its pharmacokinetic and pharmacodynamic characteristics, including β-lactamase stability and low ecological impact, support its use in urinary tract infections, bloodstream infections, intra-abdominal infections, pneumonia, and central nervous system infections. Additionally, evidence supports its utility in outpatient parenteral antimicrobial therapy (OPAT), including subcutaneous administration, and in vulnerable populations such as pediatric, elderly, and immunocompromised patients. Temocillin demonstrates a favorable safety profile, minimal disruption of gut microbiota, and cost-effectiveness. It also exhibits synergistic activity with agents like fosfomycin, further enhancing its clinical value. Most of the current evidence is derived from retrospective and observational studies. Conclusions: Temocillin emerges as a promising carbapenem-sparing option for the treatment of challenging infections caused by multidrug-resistant Gram-negative bacteria.