Antibiotic tolerance and safety in infective endocarditis: A focus on older patients

• One quarter of older adults with infective endocarditis experience antibiotic-related adverse events. • Age and functional autonomy were not associated with antibiotic intolerance. • Cognitive impairment was independently associated with adverse events. • Streptococcal infective endocarditis was associated with fewer adverse events. • Multidisciplinary endocarditis team management is conducive to safer, more individualized care. Infective endocarditis (IE) is a rare but severe disease with high morbidity and mortality, increasingly affecting older adults. Data on antibiotic tolerance in this population remain limited. We conducted a hospital network cohort study including all patients over 65 years old. diagnosed with IE between May 2016 and August 2024 in the greater Paris area. Antibiotic-related adverse events (AEs) were systematically collected, within six months of follow-up. Among 83 patients (median age: 84 years), 21 (25.3%) experienced at least one AE. Patients with AEs had longer hospital stays but similar age, autonomy, and in-hospital outcomes compared to those without AEs. Cognitive impairment was significantly associated with a higher risk of AEs, particularly in patients aged ≥ 75 years. Streptococcal IE was less frequently associated with AEs. Most AEs were biological abnormalities or clinical events, mainly involving amoxicillin and cefazolin. Age alone did not markedly affect antibiotic tolerance.