Safety concerns on the abuse potential of esketamine: Multidimensional analysis of a new anti-depressive drug on the market

Repeated subcutaneous esketamine on treatment-resistant depression: An open-label dose titration study

BACKGROUND

Ketamine has gained prominence as one of the most effective therapeutic options in unipolar treatment-resistant depression (TRD). However, most studies related to the antidepressant action of ketamine used intravenous (IV) or intranasal (IN) administration. The subcutaneous (SC) route of administration is a promising alternative, as it results in plasma levels comparable to IV, causes fewer side effects, and is easier and cheaper to administer than both IV and/or IN routes.

METHODS

In this context, we conducted an open-label clinical trial for investigating the efficacy and safety of 8 weekly sessions of SC esketamine in TRD patients (n = 30).

RESULTS

At the end of the treatment, a partial response rate of 26.09 %, a response rate of 52.17 % and remission rate of 34.78 % were observed, assessed by Montgomery-Åsberg Depression Rating Scale. Moreover, the self-reported depressive symptoms, as measured by the Beck Depression Inventory II (BDI-II), significantly decreased from the baseline to the final session, and the improvements were sustained throughout the week. Follow-up evaluations (BDI-II) up to the sixth month consistently showed scores lower than the baseline.

LIMITATIONS

The small sample size and the drop-out during the follow-up phase may limit the generalizability of the findings. Additionally, the absence of a control group necessitates cautious interpretation of causality.

CONCLUSIONS

This groundbreaking study, which addresses SC esketamine treatment for TRD, reported promising response and remission rates, as well as sustained antidepressant effects. It highlights the need for further research to improve and expand our knowledge of this innovative, more accessible, and cost-effective therapeutic approach.

Esketamine in depression: putative biomarkers from clinical research

The discovery of racemic (R, S)-ketamine as a rapid-acting antidepressant and the subsequent FDA approval of its (S)-enantiomer, esketamine, for treatment-resistant depression (TRD) are significant advances in the development of novel neuropsychiatric therapeutics. Esketamine is now recognized as a powerful tool for addressing persistent symptoms of TRD compared to traditional oral antidepressants. However, research on biomarkers associated with antidepressant response to esketamine has remained sparse and, to date, has been largely extrapolated from racemic ketamine studies. Genetic, proteomic, and metabolomic profiles suggest that inflammation and mitochondrial function may play a role in esketamine's antidepressant effects, though these preliminary results require verification. In addition, neuroimaging research has consistently implicated the prefrontal cortex, striatum, and anterior cingulate cortex in esketamine's effects. Esketamine also shows promise in perioperative settings for reducing depression and anxiety, and these effects appear to correlate with increased peripheral biomarkers such as brain-derived neurotrophic factor and serotonin. Further indications are likely to be identified with the continued repurposing of racemic ketamine, providing further opportunity for biomarker study and mechanistic understanding of therapeutic effects. Novel methodologies and well-designed biomarker-focused clinical research trials are needed to more clearly elucidate esketamine's therapeutic actions as well as biologically identify those most likely to benefit from this agent, allowing for the improved personalization of antidepressant treatment.

Patterns of ketamine use among people with substance use disorder in France: Multisource analysis of the data from the French Addictovigilance Network

BACKGROUND

Due to its psychoactive effects, ketamine has become a drug used for non-medical purpose.

OBJECTIVES

To assess the latest trends in ketamine use among people with substance use disorder and to characterize its clinical complications using complementary health data sources of the French Addictovigilance Network.

METHODS

First, we extracted all reports involving ketamine from 2012 to 2021 from the database of the OPPIDUM program (i.e., a multicentric program conducted in collaboration with hundreds of substance abuse treatment facilities that collects data on drugs used by subjects with substance use disorders). We described the reports globally and the changes from 2012 to 2021. Second, we extracted all cases involving ketamine from July 2020 to December 2022 from the French National Pharmacovigilance Database (BNPV). We identified the cases related to ketamine use among people with substance use disorder and described them.

RESULTS

There was a 2.5-fold increase in the number of ketamine users with substance use disorder in the OPPIDUM program, from 35 (0.7%) subjects in 2012 to 89 (1.7%) subjects in 2021. There was an increase in the proportion of subjects who were daily users, had distress upon discontinuation, and presented addiction. There were 238 cases related to ketamine use among people with substance use disorder in the French National Pharmacovigilance Database from July 2020 to December 2022. Among them, 94 (39.5%) cases involved ketamine use disorder, 20 (8.4%) cases involved urinary tract and kidney symptoms, and 13 (5.5%) cases involved hepatobiliary symptoms.

CONCLUSION

The trend observed over 10 years reflects the growth in ketamine use among people with substance use disorder, although it does not allow to estimate the rates of non-medical use of ketamine in the general population. Ketamine-induced uropathy and cholangiopathy are reported in ketamine users with substance use disorder, especially in case of repeated and/or prolonged use of high doses.

Apoptotic mechanism of development inhibition in zebrafish induced by esketamine

Esketamine, a widely used intravenous general anesthetic, is also employed for obstetric and pediatric anesthesia, and depression treatment. However, concerns regarding esketamine abuse have emerged. Moreover, the potential in vivo toxicity of esketamine on growth and development remains unclear. To address these concerns, we investigated the effects of esketamine exposure on developmental parameters, cell apoptosis, and gene expression in zebrafish. Esketamine exposure concentration-dependently decreased the heart rate and body length of zebrafish embryos/larvae while increasing the hatching rate and spontaneous movement frequency. Developmental retardation of zebrafish larvae, including shallow pigmentation, small eyes, and delayed yolk sac absorption, was also observed following esketamine treatment. Esketamine exposure altered the expression of apoptosis-related genes in zebrafish heads, primarily downregulating bax, caspase9, caspase3, caspase6, and caspase7. Intriguingly, BTSA1, a Bax agonist, reversed the anti-apoptotic and decelerated body growth effects of esketamine in zebrafish. Collectively, our findings suggest that esketamine may hinder embryonic development by inhibiting embryonic apoptosis via the Bax/Caspase9/Caspase3 pathway. To the best of our knowledge, this is the first study to report the lethal toxicity of esketamine in zebrafish. We have elucidated the developmental toxic effects of esketamine on zebrafish larvae and its potential apoptotic mechanisms. Further studies are warranted to evaluate the safety of esketamine in animals and humans.

What clinicians need to know about intranasal esketamine for treatment-resistant depression?

OBJECTIVE

To review the usefulness of esketamine for treatment-resistant depression.

METHOD

Pivotal trials of intranasal esketamine in treatment-resistant depression were synthesized as a narrative review.

RESULTS

Esketamine is postulated to act through antagonism of N-methyl-D-aspartate (NMDA) glutamate receptors, but opioidergic effects may also be involved. Unlike intravenous ketamine, esketamine is given intranasally (under clinical observation), usually in addition to an oral antidepressant. Trials compared esketamine plus antidepressant versus placebo plus antidepressant. At 4 weeks, remission was 37% higher with esketamine/antidepressant than placebo/antidepressant. Speed of response and improvement in suicidality were comparable. In stable remitters on esketamine/antidepressant, 45% relapsed when esketamine was withdrawn over the following 6 months (whereas 25% relapsed on esketamine/antidepressant). Response appears less likely in patients with multiple antidepressant failures. Adverse effects include dissociation, dizziness, nausea, sedation, and headache but no psychosis. Hypertension affected 13%, especially older patients. Dose frequency is twice-weekly for 4 weeks, then weekly/fortnightly thereafter. No abuse has been reported. Unsubsidised cost may be beyond the reach of many Australians.

CONCLUSION

Intranasal esketamine plus antidepressant has been approved by regulators as moderately effective and acceptably tolerable for treatment-resistant depression. Cost is a drawback. Use often needs to be long-term and vigilance for abuse is essential.

Craving and addictive potential of esketamine as side effects?

INTRODUCTION

Esketamine was approved for adults with treatment-resistant depression (TRD) in conjunction with an oral antidepressant, and for treating depressive symptoms in adults with major depressive disorder with acute suicidal ideation or behavior. However, evidence of great efficacy and safety of esketamine is accompanied by a widespread concern regarding its addictive potential.

AREAS COVERED

A comprehensive review on the craving and addictive potential of ketamine and esketamine was carried out. In addition, a clinical case of a 34-year-old TRD woman treated with esketamine who experienced drug-seeking behaviors and craving symptomatology was described and critically discussed, with a particular focus on treatment strategies to manage craving in the short- and long term.

EXPERT OPINION

Esketamine showed great efficacy and safety in treating TRD and MDD with acute suicidal ideation or behavior. Our clinical experience demonstrated the presence of an additive potential, which has been favorably managed with slow esketamine de-titration and combination with bupropion. However, literature so far published is scant and shows contradictory findings. Therefore, it is crucial to promptly detect and manage craving symptomatology in esketamine-treated TRD patients. In our experience, the use of bupropion to counteract craving and addictive symptoms was proven to be effective and safe.

Ketamine and esketamine for crisis management in patients with depression: Why, whom, and how?

Currently, only a limited number of interventions can rapidly relieve depressive symptomatology in patients with major depressive disorder or bipolar disorder experiencing extreme distress. Such crises, especially when suicide attempt or ideation is involved, are a major risk factor of suicide. Ketamine, a N-methyl-d-aspartate glutamate receptor antagonist, and its enantiomer esketamine rapidly reduce depressive symptoms in depressed patients with current suicidal ideation. Recently, esketamine has been approved for use in patients with depression at risk of suicide and for psychiatric emergency by major medical agencies in the United States and Europe, whereas ketamine is increasingly used off-label. However, there is currently limited guidance on why, when, and how to use these drugs in patients with depression to treat a crisis. In this review article, we provide a succinct overview of the cellular and molecular mechanisms of action of ketamine and esketamine, and of the functional brain changes following their administration. We also summarize the major clinical studies on ketamine and esketamine efficacy in patients experiencing a crisis (generally, suicidal ideation), and propose a profile of patients who can benefit most from such drugs, on the basis of neurobiological and clinical observations. Finally, we describe the administration mode, the efficacy and tolerability profiles, the side effect management, possible concomitant treatments and the issue of deprescribing.