Ceftriaxone Usage and Resistance Rates in Internal Medicine Departments

BACKGROUND: Ceftriaxone has been recommended for empiric treatment for urinary tract and respiratory tract infections, but continued widespread use might increase resistance rates. OBJECTIVES: To determine if ceftriaxone usage has increased resistance rates over a three-year period. METHODS: We included all patients hospitalized in internal medicine departments from 2019-2021 and extracted administered antibiotics, urine, and blood cultures with resistance reports from the computerized data base. We compared the yearly proportion of patients treated with specific antibiotics and the resistance rates of urine and blood pathogens. RESULTS: Overall, 44.1% of patients received antibiotics during 63.3% of the hospital days. The proportion of patients treated with ceftriaxone increased from 22% in 2019 to around 30% in 2020 and 2021. Resistance rates to ceftriaxone were approximately 30% for _Escherichia coli_, and 40-50% for _Klebsiella pneumonia_ and _Proteus mirabulis _without significant changes over the three-year period. The overall usage rates of carbapenems and amikacin were 3.4% and 1.4% respectively, with low resistance rates that did not change over the follow-up period. The resistance rates for blood cultures were the same observed for urine bacteria. CONCLUSIONS: We conclude that despite increased usage, resistance rates to ceftriaxone have remained stable over the past three years, and rates of resistance to broader-spectrum antibiotics have remained low. Longer follow-up is necessary to determine whether resistance rates will remain stable, and studies are needed to balance the clinical benefits and drawbacks of using ceftriaxone to treat suspected bacterial infections of the urinary tract and other areas of the body.