Gastrointestinal risk profile of tigecycline, omadacycline and eravacycline: Evidence from the FDA adverse event reporting system

This study assessed the gastrointestinal (GI) safety profiles of tigecycline, omadacycline, and eravacycline through a retrospective disproportionality analysis of reports submitted to the FDA Adverse Event Reporting System (FAERS) between the second quarter of 2005 and the first quarter of 2024. Among 3,261 adverse event reports associated with these agents, 809 (24.8 %) involved gastrointestinal disorders, with tigecycline accounting for the largest proportion (588 reports), followed by omadacycline (197) and eravacycline (24). Disproportionality analysis revealed that gastrointestinal disorders ranked among the top three system organ classes for all three drugs, with positive signals observed for tigecycline (ROR = 1.63), omadacycline (ROR = 3.04), and eravacycline (ROR = 1.79), the strongest association being with omadacycline. While most GI events were consistent with known safety information, several unexpected signals were identified, including gastrointestinal haemorrhage, melena, small-intestinal obstruction, tongue discolouration, and intestinal perforation for tigecycline, as well as lip swelling and tongue discolouration for omadacycline. The median onset times of GI events were 4, 0, and 2.5 days for tigecycline, omadacycline, and eravacycline, respectively, with nearly half of the events occurring within three days of treatment initiation. These findings reveal distinct GI safety patterns among newer tetracycline-derived antibiotics and underscore the importance of early and route-specific monitoring in clinical practice.