Population Pharmacokinetics and Pharmacodynamics of the Therapeutic and Adverse Effects of Ketamine in Patients with Treatment-Refractory Depression

Intravenous ketamine versus electroconvulsive therapy for major depressive disorder or bipolar depression: A meta-analysis of randomized controlled trials

BACKGROUND

Intravenous (IV) ketamine has been evaluated alongside electroconvulsive therapy (ECT) in addressing major depressive disorder (MDD) or bipolar depression (BD), though the comparative outcomes remain inconclusive. This meta-analysis aimed to provide a systematic assessment of the efficacy, safety, and tolerability of IV ketamine relative to ECT for treating MDD or BD.

METHODS

Randomized controlled trials (RCTs) comparing IV ketamine and ECT in terms of efficacy, safety, and tolerability for MDD or BD were identified and reviewed. Three independent investigators extracted relevant data, which was synthesized using RevMan 5.3 software under a random effects model.

RESULTS

Five RCTs encompassing 664 patients diagnosed with MDD or BD were analyzed. At 24 h post-initial treatment, IV ketamine demonstrated a statistically greater reduction in depressive symptoms compared to ECT (standardized mean difference (SMD) = -0.53; 95 % CI = -1.03 to -0.04; P = 0.04; I2 = 80 %). However, no significant differences were observed between groups in terms of the study-defined response (risk ratio (RR) = 1.49; 95 % CI = 0.08 to 28.42; P = 0.79; I2 = 0 %) at 24 h. Similarly, no notable differences were found for depressive symptom improvement (SMD = -0.48; 95 % CI = -2.41 to 1.45; P = 0.63; I2 = 99 %), the study-defined response (RR: 0.96, 95 % CI: 0.70 to 1.31; P = 0.79; I2 = 75 %) or remission (RR: 0.91, 95 % CI: 0.45 to 1.82; P = 0.78; I2 = 90 %) at the end-of-treatment visit. Among the three RCTs (60 %) comparing the neurocognitive outcomes of IV ketamine and ECT through varying test batteries, results were inconsistent. IV ketamine was associated with marked increases in dissociation, blurred vision, dizziness, and diplopia, while ECT led to a significant rise in muscle pain (all Ps < 0.05). Discontinuation rates due to any cause were comparable between both groups (P > 0.05).

CONCLUSION

IV ketamine demonstrates a faster onset of antidepressant effects compared to ECT, despite both treatments yielding comparable outcomes at the end-of-treatment visit for patients with MDD or BD. However, large-scale RCTs are required to thoroughly evaluate the long-term efficacy and safety of IV ketamine relative to ECT in these populations.

Use of ketamine for treatment resistant depression: updated review of literature and practical applications to a community ketamine program in Edmonton, Alberta, Canada

Background

Though intravenous (IV) ketamine and intranasal (IN) esketamine are noted to be efficacious for treatment-resistant depression (TRD), access to each of these treatments within healthcare systems is limited due to cost, availability, and/or monitoring requirements. IV ketamine has been offered at two public hospital sites in Edmonton, Canada since 2015. Since then, demand for maintenance ketamine treatments has grown. This has required creative solutions for safe, accessible, evidence-based patient care.

Objectives

Aims of this paper are twofold. First, we will provide a synthesis of current knowledge with regards to the clinical use of ketamine for TRD. Consideration will be given regarding; off-label racemic ketamine uses versus FDA-approved intranasal esketamine, populations treated, inclusion/exclusion criteria, dosing, assessing clinical response, concomitant medications, and tolerability/safety. Second, this paper will describe our experience as a community case study in applying evidence-based treatment. We will describe application of the literature review to our clinical programming, and in particular focus on cost-effective maintenance treatments, long-term safety concerns, routes of ketamine administration other than via intravenous, and cautious prescribing of ketamine outside of clinically monitored settings.

Methodology

We conducted a literature review of the on the use of ketamine for TRD up to June 30, 2023. Key findings are reviewed, and we describe their application to our ketamine program.

Conclusion

Evidence for the use of ketamine in resistant depression has grown in recent years, with evolving data to support and direct its clinical use. There is an increasing body of evidence to guide judicious use of ketamine in various clinical circumstances, for a population of patients with a high burden of suffering and morbidity. While large-scale, randomized controlled trials, comparative studies, and longer-term treatment outcomes is lacking, this community case study illustrates that currently available evidence can be applied to real-world clinical settings with complex patients. As cost is often a significant barrier to accessing initial and/or maintenance IV or esketamine treatments, public ketamine programs may incorporate SL or IN ketamine to support a sustainable and accessible treatment model. Three of such models are described.

Ketamine for Major Depressive Disorder

Major Depressive Disorder (MDD) is a leading cause of disability worldwide. Conventional antidepressant treatment is characterised by a significant time to onset of therapeutic action (approximately 2 weeks) and fails to achieve a stable remission of symptoms in one-third of subjects with MDD. In the last 20 years the discovery of antidepressant effects of the N-methyl-d-aspartate (NMDA) receptor antagonist ketamine as a rapid acting (within hours) and sustained (up to 7 days) antidepressant has represented a major paradigm shift in the field.The present chapter reviews the pharmacology, safety, and efficacy of ketamine as a novel therapeutic agent for MDD and specifically for subjects who did not respond to conventional antidepressant (treatment resistant depression). The impact of ketamine on suicidal ideation, the availability of brain biomarkers of ketamine treatment response and the association of ketamine and psychotherapy are considered.

Efficacy and safety of a 4-week course of repeated subcutaneous ketamine injections for treatment-resistant depression (KADS study): randomised double-blind active-controlled trial

BACKGROUND

Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed.

AIMS

To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au.

METHOD

This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5-0.9 mg/kg or midazolam 0.025-0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4.

RESULTS

The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1-69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2-8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h.

CONCLUSIONS

Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.

Evidence for the beneficial effect of ketamine in the treatment of patients with post-traumatic stress disorder: A systematic review and meta-analysis

Post-traumatic stress disorder (PTSD) is an anxiety disorder with manifestations somatic resulting from reliving the trauma. The therapy for the treatment of PTSD has limitations, between reduced efficacy and "PTSD pharmacotherapeutic crisis". Scientific evidence has shown that the use of ketamine has benefits for the treatment of depressive disorders and other symptoms present in PTSD compared to other conventional therapies. Therefore, this study aims to analyze the available evidence on the effect of ketamine in the treatment of post-traumatic stress. The systematic review and the meta-analysis were conducted following PRISMA guidelines and RevManager software, using randomized controlled trials and eligible studies of quality criteria for data extraction and analysis. The sample design evaluated included the last ten years, whose search resulted in 594 articles. After applying the exclusion criteria, 35 articles were selected, of which 14 articles were part of the sample, however, only six articles were selected the meta-analysis. The results showed that the ketamine is a promising drug in the management of PTSD with effect more evident performed after 24 h evaluated by MADRS scale. However, the main limitations of the present review demonstrate that more high-quality studies are needed to investigate the influence of therapy, safety, and efficacy.

Efficacy and Safety of Subcutaneous Esketamine in the Treatment of Suicidality in Major Depressive Disorder and Bipolar Depression

BACKGROUND AND OBJECTIVE

Affective disorders account for most cases of suicide. The pharmacological arsenal to treat suicidality is limited and available agents take too long to take effect. A large body of evidence shows optimal results of ketamine for treating depression, but the evidence concerning suicidality has not been fully described. We report the first real-world study of severely depressed patients presenting with suicide ideation who were treated with repeated administration of subcutaneous esketamine.

METHODS

We analyzed data from 70 acutely depressed subjects diagnosed with resistant major depressive disorder or bipolar depression. Subjects were administered subcutaneous esketamine once a week for 6 weeks. The primary efficacy endpoint, the change from baseline to 24-h post-administration 6 in the item 10 Montgomery-Åsberg Depression Rating Scale score, was analyzed using a mixed-effects repeated-measures model.

RESULTS

There were significant effects for time on item 10 Montgomery-Åsberg Depression Rating Scale scores (p < 0.0001) but not for a time × diagnosis interaction (p = 0.164) from baseline to the end of the study. Efficacy of esketamine did not differ between groups (major depressive disorder vs bipolar depression) at any timepoint. Statistical significance on suicidality scores was observed from 24 h after the first administration (p < 0.001), and a further reduction was observed with repeated administrations. Esketamine was safe and well tolerated. Mean heart rate remained stable during the administrations and the blood pressure increase was self-limited.

CONCLUSIONS

Repeated subcutaneous esketamine administration had significant anti-suicidality effects in both major depressive disorder and bipolar groups, with a rapid onset of action and a good tolerability profile. Large randomized controlled trials are warranted to confirm these preliminary findings.