Alone or combined with clavulanic acid, amoxicillin is widely prescribed. Therapeu-tic indications include a broad spectrum of infections. Combination with clavulanic acid kept the known activity of amoxicillin against strains producing β-lactamase. Only poor studies exist on adverse reactions and antibiotic resistance by using databanks reporting spontaneous signals caused by amoxicillin or the combination amoxicillin/clavulanic acid. Antimicrobial resistance is an overlooked adverse event and pharmacovigilance da-tabases could serve as a tool in tracking resistance. On this basis, a study to define the safety profile of amoxicillin and amoxicillin/clavulanic acid and to increase the knowledge necessary to support the battle against antimicrobial resistance was undertook through the analysis of pharmacovigilance databases. Signals of suspected adverse reac-tions to amoxicillin and to the combination amoxicillin/clavulanic acid of the data system EudraVigilance in the years 2020-2024, were analyzed. A disproportionality analysis for hepatotoxic reactions and for drug inefficiency was performed comparing data of the two medicinal products. Most frequent signals were about “Skin and subcutaneous disorders” for both the drugs. Disproportionate analysis of cases signaling “Hepatobiliary disor-ders” or “Drug inefficiency”, indicates significant increase of these signals with the com-bination amoxicillin/clavulanic acid compared to amoxicillin. The combination amoxicil-lin/clavulanic acid has previously been associated with higher risk of hepatotoxicity, however, it is the first time that a post-marketing surveillance shows that antimicrobial resistance has a greater probability to occur with the combination in comparison to amoxicillin.
Ammendolia et al. (Mon,) studied this question.