5PSQ-165 Incidence and management of etoposide hypersensitivity in paediatric patients

Background and importance Etoposide is widely used in paediatric chemotherapy treatment, although hypersensitivity can be severe and treatment limiting. There are conflicting data in the literature regarding the incidence of etoposide hypersensitivity reactions in adults and children. Reported rates of hypersensitivity range from 2% to 51%. Aim and objectives The aim of this study was to assess the incidence of etoposide hypersensitivity and to evaluate potential risk factors for hypersensitivity in paediatric patients in a third level hospital. Material and methods A retrospective observational study was conducted in paediatric patients treated with etoposide from June 2013 to September 2020. Data collected were: demographics (age, sex), diagnosis, dose, infusion rate, infusion concentration, symptoms of hypersensitivity, CTCAE grade of hypersensitivity reaction and management of hypersensitivity reaction. Data were collected from the electronic medical records and pharmacy records. Results 213 patients were treated with etoposide during the period of the study. Mean age was 6.75 (range 0.16–17) years and 58.68% were male. Indications for etoposide were lymphocytic acute leukaemia 20.18%; neuroblastoma 16.9%; Ewing’s sarcoma 16.9%; Hodgkin’s lymphoma 11.27%; myeloid acute leukaemia 8.9%; and other 25.82%. Doses administered ranged from 200 to 100 mg/m2 and from 2.5 to 6 mg/kg. Median infusion rate was 55 (2–200) mg/hour. Median infusion concentration was 0.3 (0.2–0.5) mg/mL. Hypersensitivity reactions occurred in 23 (10.8%) patients; 3 and 20 cases were classified as grade I and grade II of the CTCAE, respectively. Symptoms of hypersensitivity were lip cyanosis (n=7), pruritus (n=7), flushing (n=7), nausea (n=5), cutaneous rash (n=5), cough (n=4), rhinoconjunctivitis (n=1), hypotension (n=1), shortness of breath (n=1), abdominal pain (n=1), facial paraesthesia (n=1), fever (n=1) and angioedema (n=1). All hypersensitivity reactions were successfully managed with medication (corticoids and antihistamines). Subsequent doses were administered with premedication and reduction of the infusion rate. We did not observe any statistically significant associations between the variables collected and the appearance of hypersensitivity reactions. Conclusion and relevance The incidence of hypersensitivity reactions was moderate, affecting approximately 10% of patients. All hypersensitivity reactions were mild and were resolved by standard treatment. We were unable to establish if any of the variables collected were risk factors for hypersensitivity reactions, probably due to the small sample size derived from the rarity of the event. Other studies have observed a relationship between the rate of infusion and the concentration of etoposide. References and/or acknowledgements Conflict of interest No conflict of interest