Effectiveness and Safety of Flumazenil Augmentation During Electroconvulsive Therapy

Benzodiazepines are considered to negatively affect seizure quality and duration during electroconvulsive therapy (ECT). Several researchers have advocated the use of flumazenil, a competitive benzodiazepine receptor antagonist, for patients treated with benzodiazepines during ECT. However, clinical evidence regarding flumazenil use in ECT remains sparse. The aim of this study is to investigate the effects of flumazenil on seizure duration and adverse effects.

All patients with depressive disorders, treated with flumazenil during a course of ECT in 2019 in a tertiary hospital, were identified through a retrospective chart review. Seizure duration was recorded before and after flumazenil administration. Effectiveness of ECT was assessed using the Inventory of Depressive Symptomatology and the Bush-Francis Catatonia Rating Scale. Postictal agitation was ascertained by identifying patients who received additional sedatives immediately after ECT or who needed physical restraint.

Twenty-six patients were included, receiving a total of 363 treatments, of which 263 were augmented with flumazenil. Flumazenil administration increased electroencephalogram seizure duration on average with 10.5 seconds comparing ECT with or without flumazenil ( P = 0.003). In 21.8% of the cases, no increase in seizure duration was observed. Postictal agitation occurred at least once in 34.6% of the patients receiving flumazenil during their course of ECT.

Our results show that flumazenil increases seizure duration, albeit with limited clinical implications. Noteworthy, the prevalence of postictal agitation is high. When confronted with short seizures, clinicians should therefore deploy other available techniques to lower seizure threshold before considering flumazenil.