Evaluation of fosaprepitant-associated hypersensitivity reactions at a National Cancer Center

At our institution, an increased incidence of hypersensitivity reactions was reported following standardization of fosaprepitant as the preferred agent for the prophylaxis of chemotherapy induced nausea and vomiting (CINV) caused by highly emetogenic therapies. The purpose of this evaluation was to assess the incidence of systemic hypersensitivity reactions (HSRs) to fosaprepitant infusions compared to available literature.This evaluation is a retrospective review of electronic health records of adult patients who received their first dose of fosaprepitant for CINV prophylaxis beginning January 1, 2017 through June 30, 2017 at the University of Colorado Cancer Center outpatient infusion center. Subjects were identified using medication administration reports. Individual chart reviews were performed for all patients who received fosaprepitant during the specified timeframe and had a reaction reported on the same date.A total of 868 patients received fosaprepitant in the outpatient infusion center during the study time period. Four patients (0.461%) had a systemic HSR attributed to fosaprepitant. Two of the reactions were reported as HSRs in the adverse reaction reporting system and two were found in provider notes during chart review. Due to the small sample size, risk factors for HSRs to fosaprepitant were not able to be determined.The incidence of HSRs to fosaprepitant at our institution was found to be consistent with the <1% incidence currently noted in literature. Based on these findings, opportunities have been identified for education on fosaprepitant-associated HSRs, proper documentation and patient-specific precautions.