Characterizing the Use of High-Dose Amoxicillin for the Treatment of Bacteremia

Treatment of bacteremia has traditionally consisted of a 7-14-day course of intravenous (IV) antibiotics. Transitioning from IV to oral (PO) antibiotics in uncomplicated cases of Gram-negative and Gram-positive bacteremia is non-inferior to a complete course of IV antibiotics. High-dose oral amoxicillin has been used in practice for treating bacteremia but has limited safety and efficacy data. We conducted a retrospective chart review between June 2022 and June 2024 to characterize the use of high-dose amoxicillin and evaluate its efficacy and safety. A convenient sample size of 100 patients was used. Patients admitted to hospital who received at least one dose of high-dose amoxicillin (1 g PO TID) for the treatment of bacteremia were included. Patients undergoing hemodialysis and patients receiving amoxicillin for other infections were excluded. The average patient was a 60-year-old male (66% male) with a Gram-positive respiratory or skin source bacteremia. The median time to transition to oral amoxicillin was 5 days. The median duration of total treatment was 14 days. Respiratory sources were treated for a shorter duration, whereas skin sources were treated for longer. Readmission to hospital occurred in 28% of cases. The majority of readmissions were unrelated to the original infection, and 92% of patients were cured. There were no observed adverse events, bacteremia relapses, or deaths. In this observational study, transitioning to high-dose oral amoxicillin was primarily used for treatment of uncomplicated respiratory and skin infections with secondary bacteremia. A high rate of clinical success was observed with high-dose PO amoxicillin, with no adverse events reported.