Effect of Concomitant Benzodiazepine Use on Efficacy and Safety of Esketamine Nasal Spray in Patients with Major Depressive Disorder and Acute Suicidal Ideation or Behavior: Pooled Randomized, Controlled Trials

PURPOSE: The impact of benzodiazepines on the efficacy and safety of esketamine as a rapid-acting antidepressant remains unclear. MATERIALS AND METHODS: Data from two identically designed, randomized double-blind studies were pooled and analyzed on a post-hoc basis. In both studies, adults with major depressive disorder with acute suicidal ideation or behavior were randomized to placebo or esketamine 84 mg nasal spray twice-weekly for 4 weeks, each with comprehensive standard-of-care (initial hospitalization and newly initiated or optimized oral antidepressant[s]). Efficacy and safety were analyzed in two groups based on whether patients used concomitant benzodiazepines, which were prohibited within 8 hours before and 4 hours after the first dose of esketamine and within 8 hours of the primary efficacy assessment at 24 hours. The primary efficacy endpoint – change from baseline to 24 hours post-first dose in Montgomery-Asberg Depression Rating Scale (MADRS) total score – was analyzed using ANCOVA. RESULTS: Most patients (309/451, 68.5%) used concomitant benzodiazepines. Greater decrease in MADRS total score was observed with esketamine (mean [SD]: −16.1 [11.73]) versus placebo (−12.6 [10.56]) at 24 hours (least-squares mean difference: −3.7, 95% CI: −5.76, −1.59). The differences between the esketamine and placebo groups were clinically meaningful, irrespective of benzodiazepine use (benzodiazepine: −4.3 [−6.63, −1.89]; no benzodiazepine: −3.1 [−6.62, 0.45]). Among patients taking esketamine, change in MADRS total score was not significantly different between patients taking benzodiazepines (−15.8 [11.27]) versus those not taking benzodiazepines (−16.8 [12.82]) (least-squares mean difference: 1.1, [−2.24, 4.45]). Among esketamine-treated patients, the incidence of sedation was higher with benzodiazepine use, whereas dissociation was similar. CONCLUSION: Benzodiazepines do not meaningfully affect the rapid-acting antidepressant effect of esketamine at 24 hours post-first dose among patients with MDD and acute suicidal ideation or behavior.