Efflux Pump Inhibitors and Antimicrobial Resistance: A Bibliometric Analysis of Web of Science-Indexed Literature (1991–2025)

Background: Antimicrobial resistance (AMR) is a major global health threat, with bacterial efflux pumps representing an important mechanism that reduces antibiotic efficacy by actively expelling antimicrobial agents from bacterial cells. Efflux pump inhibitors (EPIs) have therefore emerged as promising antibiotic adjuvants. Methods: This study presents a bibliometric analysis of EPI research published between 1991 and 2025 using the Web of Science Core Collection. Of 1078 identified publications, 835 original research articles were included. Publication trends, citation patterns, country and author contributions, scientific disciplines, thematic clusters, and keyword co-occurrence patterns were analyzed using VOSviewer version 1.6.21. Results: Publication output showed an overall upward trend over the study period, with higher annual publication counts in the later years. The United States led in publications (156), citations (9122), and collaborations (80), followed by India (103) and China (94). Lomovskaya et al. (2001) was the most cited article (752 citations). Microbiology was the leading research category (329; 39.4%), followed by Pharmacology & Pharmacy (269; 32.2%). Phytochemicals represented 7.3% of meso-level citation topics. Conclusions: EPI research has expanded over the study period, encompassing a multidisciplinary range of topics primarily related to antimicrobial resistance mechanisms, bacterial efflux systems, and inhibitor discovery. These findings underscore the need to strengthen the connection between fundamental research and translational applications, particularly through the systematic evaluation of EPI efficacy, safety, and therapeutic potential.