Safety of subcutaneous versus intravenous ceftriaxone administration in older patients: A retrospective study

Abstract Background Antibiotics play a central role in infection management. In older patients, antibiotics are frequently administered subcutaneously. Ceftriaxone pharmacokinetics after subcutaneous administration is well documented, but little data are available on its safety. Methods We compared the occurrence of adverse events associated with ceftriaxone administered subcutaneously versus intravenously in ≥75‐year‐old patients. We used data from a single‐center, retrospective, clinical‐administrative database to compare the occurrence of adverse events at day 14 and outcome at day 21 in older patients who received ceftriaxone via the subcutaneous route or the intravenous route at Rennes University Hospital, France, from May 2020 to February 2023. Results The subcutaneous and intravenous groups included 402 and 3387 patients, respectively. Patients in the subcutaneous group were older and more likely to receive palliative care. At least one adverse event was reported for 18% and 40% of patients in the subcutaneous and intravenous group, respectively (RR = 2.21). Mortality at day 21 was higher in the subcutaneous route group, which could be linked to between‐group differences in clinical and demographic features. Conclusions In ≥75‐year‐old patients, ceftriaxone administered by the subcutaneous route is associated with less‐adverse events than by the intravenous route. The subcutaneous route, which is easier to use, has a place in infection management in geriatric settings.