Inappropriate use of antibiotics in primary care for patients with infective endocarditis.

Inappropriate use of antibiotics without blood cultures could delay diagnosis of infective endocarditis (IE). The pattern of use of antibiotics by primary care physicians who were later diagnosed with IE is unclear. A retrospective cohort study of patients with a definite diagnosis of IE at a community teaching hospital in the Kanagawa prefecture was performed over a 12-year period (2006-2017). Of the 145 patients, 38 patients (26%) had initially attended primary care clinics. The mean age was 63 ± 18 years, and 24 patients (63%) were men. Only one patient (3%) was prescribed antibiotics after obtaining blood cultures. Twenty patients (53%) received antibiotics. Fluoroquinolones (50%) and macrolides (25%) were the most antibiotics prescribed. There were no obvious differences in physicians' specialty between the prescriber and non-prescriber groups. Compared to patients without antibiotic prescription, those prescribed antibiotics had delayed admission and higher mortality (10 vs. 14 days and 11% vs. 30%, respectively). In conclusions, about one-quarter of IE patients initially attended primary care clinics. Of them, about half were inappropriately prescribed antibiotics (without blood cultures obtaining). IE patients receiving inappropriate antibiotics potentially have a worse outcome.