This study aims to assess the efficacy and safety of intranasal esketamine as maintenance antidepressant therapy in patients who have demonstrated clinical improvement with off-label intravenous racemic ketamine for treatment-resistant depression.
Retrospective case series of 10 consecutive outpatients with treatment-resistant depression who responded to an induction course of IV racemic ketamine and were switched to intranasal esketamine for maintenance.
IV ketamine was given at 0.5 mg/kg with flexible dosing up to 1.0 mg/kg (series of six infusions over 14–21 days). IN esketamine was started at 28 mg or 56 mg and titrated to 84 mg; outcomes included MADRS, PHQ‑9, CGI‑I, vital signs and adverse events, with REMS monitoring for IN esketamine.
Outpatients with TRD who responded to IV racemic ketamine switched to intranasal esketamine for maintenance; concomitant psychotropic medications continued.
Initial 28 mg (n=1) or 56 mg (n=9) then titrated to target 84 mg for remainder of treatments; monitored under REMS.
Subanaesthetic IV racemic ketamine induction (0.5 mg/kg, titrated to 1.0 mg/kg); series of six infusions over 14–21 days, then weekly x4 if response, then variable maintenance.