Intravenous ketamine appears to be more efficacious than intranasal esketamine for the treatment of depression.
Findings
| Outcome | Intranasal Esketamine | Intravenous Ketamine |
| Overall Response Rate | 58% | 75% |
| Remission Rate | 60% | 78% |
| Dropout Rate | 58% | 43% |
Background
Ketamine appears to have a therapeutic role in certain mental disorders, most notably depression. However, the comparative performance of different formulations of ketamine is less clear.
Objectives: This study aimed to assess the comparative efficacy and tolerability of racemic and esketamine for the treatment of unipolar and bipolar major depression.
Design: Systematic review and meta-analysis.
Data sources: PubMed, MEDLINE, Embase, PsycINFO, the Cochrane Central Register of Controlled Clinical Trials, and the Cochrane Database of Systematic Reviews for relevant studies published since database inception and December 17, 2019. 24 trials representing 1877 participants were pooled.
Study eligibility criteria: Randomized controlled trials examining racemic or esketamine for the treatment of unipolar or bipolar major depression.
Outcomes: Primary outcomes were response and remission from depression, change in depression severity, suicidality, retention in treatment, drop-outs, and drop-outs due to adverse events.
Analysis: Evidence from randomized controlled trials was synthesized as rate ratios (RRs) for treatment response, disorder remission, adverse events, and withdrawals and as standardized mean differences (SMDs) for change in symptoms, via random-effects meta-analyses.
Conclusions
Intravenous ketamine appears to be more efficacious than intranasal esketamine for the treatment of depression. 78% of patients achieved remission of depression with intravenous ketamine infusions compared to 60% for intranasal esketamine.
Keywords: Bipolar disorder; Depression; Depressive disorder; Esketamine; Ketamine; Major; Meta-analysis; Randomized controlled trials.