Ketamine for acute suicidality in the emergency department: A systematic review

New pharmacotherapies to tackle the unmet needs in bipolar disorder: a focus on acute suicidality

INTRODUCTION

Suicidal behavior is relatively frequent in patients with bipolar disorder (BD) and constitutes their most frequent cause of death. Suicide rates remain high in patients with BD despite adherence to guidelines recommending lithium as first line, and/or antidepressants, antipsychotics, psychotherapy, psychosocial interventions, and electroconvulsive therapy. Hence the need to identify more effective and rapid anti-suicide interventions.

AREAS COVERED

To tackle the unmet needs of pharmacotherapy, we investigated the PubMed database on 24-25 January 2024 using strategies like ('acute suicid*'[ti] OR 'suicide crisis syndrome' OR 'acute suicidal affective disturbance') AND (lithium[ti] OR clozapine[ti]), which obtained 3 results, and ('acute suicid*'[ti] OR 'suicide crisis syndrome' OR 'acute suicidal affective disturbance') AND (ketamine[ti] OR esketamine[ti] OR NMDA[ti] OR glutamat*[ti]), which yielded 14 results. We explored glutamatergic abnormalities in BD and suicide and found alterations in both. The noncompetitive NMDS antagonist ketamine and its S-enantiomer esketamine reportedly decrease acute suicidality.

EXPERT OPINION

Intranasal esketamine or subcutaneous ketamine, single-bolus or intravenous, and possibly other glutamate receptor modulators may improve suicidal behavior in patients with unipolar and bipolar depression. This may be achieved through prompt remodulation of glutamate activity. The correct use of glutamatergic modulators could reduce acute suicidality and mortality in patients with BD.

Ketamine and esketamine in suicidal thoughts and behaviors: a systematic review

BACKGROUND

More than 2% of the general population experience suicidal ideas each year and a large number of them will attempt suicide. Evidence-based therapeutic options to manage suicidal crisis are currently limited.

OBJECTIVES

The aim of this study was to overview the findings on the use of ketamine and esketamine for the treatment of suicidal ideas and acts.

DESIGN

Systematic review.

DATA SOURCES AND METHODS

PubMed, article references, and Clinicaltrials.gov up to June 30, 2022. Meta-analyses published within the last 2 years were also reviewed.

RESULTS

We identified 12 randomized controlled trials with reduction of suicidal ideation as the primary objective and 14 trials as secondary objectives. Intravenous racemic ketamine was superior to control drugs (placebo or midazolam) within the first 72 h, in spite of large placebo effects. Adverse events were minor and transient. In contrast, intranasal esketamine did not differ from placebo in large-scale studies. Limitations, clinical considerations, and opportunities for future research include the following points: large placebo effects when studying suicidal ideation reduction; small concerns about blinding quality due to dissociative effects; no studies on the risk/prevention of suicidal acts and mortality; lack of studies beyond affective disorders; no studies in adolescents and older people; lack of knowledge of long-term side effects, notably liability for abuse; no robust predictive markers; limited understanding of the mechanisms of ketamine on suicidal ideas; need for improved assessment of suicidal ideation in clinical trials; need for studies in outpatient settings, emergency room, and liaison consultation; need for research on ketamine administration; limited knowledge on the positive and negative effects of concomitant treatments.

CONCLUSION

Overall, there is compelling evidence for a favorable short-term benefit-risk balance with intravenous racemic ketamine but not intranasal esketamine. The place of ketamine will have to be defined within a multimodal care strategy for suicidal patients. Caution remains necessary for clinical use, and pharmacovigilance will be essential.

Ketamine for suicidality: an umbrella review

The urgent need for appropriate treatment for suicide, the tenth leading cause of death, has led to numerous studies. This study aims to systematically identify and appraise systematic reviews with or without meta-analyses investigating ketamine in suicidal ideation and behaviors. The study protocol was published in PROSPERO (CRD42021285320). Scopus, ISI, Embase, PubMed, CINAHL, PsycINFO, Cochrane Library, Google Scholar, and two registries were searched on October 29 without any restrictions for systematic reviews investigating the efficacy of ketamine on suicidal ideation and behaviors. The primary outcome was the final inference of ketamine effectiveness. A formal narrative synthesis was conducted, and the AMSTAR-2 tool was used to evaluate the quality of the studies. No funding was received. Of 27 studies that addressed ketamine for suicidal ideation, only four reported mixed or negative results, and out of nine reviews, esketamine was significantly beneficial only in five. A transient rise in pulse rate and blood pressure, dissociation, confusion, blurred vision, nausea, and vertigo were of the most common adverse effects; however, most were mild. More than two-thirds of the included studies qualified as low or critically low quality. Preliminary evidence for the short-term efficacy of ketamine in suicidality was noted by the majority of reviews; however, long-term effects remained unknown. Due to the non-high quality of many studies and the limitations of core studies, further studies are required.