Background: Flumazenil has been available since 1991 for the treatment of acute benzodiazepine overdose, yet many physicians remain reluctant to use it.
Objectives: To evaluate the frequency of flumazenil use for benzodiazepine overdose at a large, urban, tertiary care center. To assess its effectiveness and associated adverse events.
Methods: The study was conducted in an emergency department with approximately 220,000 annual visits. Medical records of patients who received a medical toxicology consultation and were treated with flumazenil between 1 January 2019, and 31 December 2023 were reviewed. Data collected included patient demographics, medical history, substances involved, presence of seizures, indications for flumazenil use, clinical response, and adverse effects.
Results: Of 263 patients evaluated for suspected benzodiazepine overdose and referred to medical toxicology, 79 received flumazenil and comprised the study cohort. Among them, 64 cases involved intentional overdose. Indications for flumazenil administration included severe overdose with impaired consciousness and ventilatory failure (37 patients) or without ventilatory failure (42 patients). Co-ingestion of tricyclic antidepressants was documented in 4 patients and other antidepressants or antipsychotics in 35. Clinical improvement, including enhanced consciousness and/or reduced need for mechanical ventilation, was observed in all 79 patients. No adverse effects, including seizures, were reported.
Conclusions: In this retrospective cohort, flumazenil was administered without serious adverse events and was associated with improved alertness and ventilation. While caution is required, particularly in mixed overdoses, flumazenil may have a role in managing benzodiazepine-induced respiratory depression when guided by toxicology consultation.