Use of Ketamine in Clinical Practice: A Time for Optimism and Caution

Oral prolonged-release ketamine in treatment-resistant depression - A double-blind randomized placebo-controlled multicentre trial of KET01, a novel ketamine formulation - Clinical and safety results

INTRODUCTION

We investigated the antidepressant effects of a novel oral prolonged-release formulation of racemic ketamine (KET01) in patients suffering from treatment-resistant depression (TRD) as add-on therapy.

MATERIAL AND METHODS

Patients were randomized to an additional 160 mg/day or 240 mg/day KET01 or placebo for 14 days. The primary endpoint was change in Montgomery-Åsberg Depression Rating Scale (MADRS) scores from baseline to day 15. For treatment group comparisons, we used ANOVA with pairwise least squares mean difference tests in a mixed model repeated measures analysis.

RESULTS

Twenty-seven patients completed the double-blind protocol before trial premature termination due to poor recruitment during the COVID-19 pandemic. Mean (SD) MADRS scores on day 15 were 23 (10.32) in placebo, 25 (8.28) with 160 mg/day and 17 (10.32) with 240 mg/day KET01. MADRS change was numerically larger but statistically non-significant in the 240 mg/day KET01 group vs placebo on day 7 (-5.67; p = 00.106) and day 15 was (difference: 4.99; p = 00.15). In exploratory analysis, baseline leukocyte count correlated with response to KET01 (p = 00.01). Distribution of adverse event rates were comparable between the treatment arms. Safety analysis did not identify increased risk of suicidality, dissociation, hear rate, systolic and diastolic blood pressure associated with trial treatment.

DISCUSSION

Our results suggest that adjunctive oral administration of prolonged-release ketamine at a dose of 240 mg/day shows a positive, although statistically non-significant, trend towards antidepressant efficacy, however, the benefit could not be confirmed due to premature trial termination. Given its ease of use and low side effects, further trials are warranted to investigate this route of ketamine administration as a promising potential treatment of TRD.

Views on Using Psychoactive Substances to Self-Manage Functional Neurological Disorder: Online Patient Survey Results

Objective: Functional neurological disorder (FND) causes a high burden of disability and distress. Although it is a common disorder, there is a pressing need for improved access to evidence-based treatments. With difficulties in finding effective treatment, some people with FND may seek alternative means of symptom relief, such as legal and illicit psychoactive substances, although the prevalence and nature of such self-management strategies are currently unclear. Additionally, psychoactive substances may represent novel treatment research opportunities, particularly for those with suboptimal improvement. The investigators examined the use of self-management techniques, as well as perspectives on novel therapies, in this patient population. Methods: An online survey was created to assess self-management strategies and views on novel treatments for FND, including psychedelic therapy. The survey was accessible for 1 month, and respondents were recruited internationally through social media and patient groups. A total of 1,048 respondents from 16 countries completed the survey. Results: Almost half (46%) of 980 respondents reported having tried legal psychoactive substances for the management of their FND symptoms and, on average, nicotine, alcohol, and cannabidiol were reported as modestly effective. Additionally, 15% of respondents reported having used illicit substances, mostly cannabis, to manage FND, with the majority reporting moderate effectiveness and experiencing no or minimal physical (90%) and psychological (95%) sequelae. Many respondents (46%) reported that they would be willing to try medically supervised psychedelic therapy (with 19% of respondents ambivalent) if it were found to be safe and effective. Conclusions: Many people with FND seek alternative means of symptom management outside usual medical care, including legal and illicit psychoactive substances. Further research exploring novel treatment options, such as psychedelics, in FND may be warranted.

Ketamine treatment for depression: A model of care

OBJECTIVE

Ketamine and related compounds are emerging as rapidly acting therapies for treatment-resistant depression. Ketamine differs from standard antidepressants in its speed of action, specific acute and cumulative side effects, risk of dependence and regulatory requirements. However, there is currently little guidance offering translation from research studies into clinical practice. We therefore detail a comprehensive model of care for ketamine treatment of depression.

METHOD

We formulated a set of policies and procedures for a 'compassionate use' ketamine programme that developed out of our clinical research in ketamine. These policies and procedures were formulated into a detailed model of care.

RESULTS

The current Australian and New Zealand regulatory frameworks and professional bodies' recommendations regarding ketamine are detailed along with clinical governance and infrastructure considerations. We next describe a four-step model comprising initial assessment, pre-treatment, treatment and post-treatment phases. The model comprises thorough psychiatric and medical assessments examining patient suitability, a rigorous consenting process and structured safety monitoring across an acute treatment course or maintenance therapy. Our ketamine dose-titration method is detailed allowing flexible dosing of patients across a treatment course enabling individualised treatment.

CONCLUSION

The model of care aims to bridge the gap between efficacy studies and clinical care outside of research settings as ketamine and related compounds become increasingly important therapies for treatment-resistant depression.

The effectiveness of repeated intravenous ketamine on depressive symptoms, suicidal ideation and functional disability in adults with major depressive disorder and bipolar disorder: Results from the Canadian Rapid Treatment Center of Excellence

BACKGROUND

The effectiveness, tolerability, and safety of intravenous (IV) ketamine in adults with treatment resistant depression (TRD) receiving care in real-word settings is insufficiently characterized. Herein, results from a naturalistic, retrospective study are presented from a Canadian outpatient IV ketamine clinic.

METHODS

Adults (N = 213; M_age = 45) with Major Depressive Disorder or Bipolar Disorder, with a minimum of Stage 2 antidepressant resistance, received IV ketamine at a community-based multi-disciplinary clinic. The primary outcome measure was change from baseline to post-infusion 4 on the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR₁₆; n = 190). Secondary measures included QIDS-SR₁₆-measured response and remission rates, changes from baseline to endpoint in Generalized Anxiety Disorder-7 Scale (GAD-7; n = 188) and the Sheehan Disability Scale (SDS; n = 168).

RESULTS

Significant improvement in total depressive symptoms severity (p < 0.0001) was observed after four infusions of IV ketamine 0.5-0.75 mg/kg. Moreover, the response rate (QIDS-SR₁₆ total score change ≥ 50%) was 27% and remission (QIDS-SR₁₆ total score ≤5) rate was 13%. Patients receiving IV ketamine exhibited anxiolytic effects (p < 0.0001,), improved overall psychosocial function (p < 0.0001), and reduced suicidal ideation (p < 0.0001). Compared to the baseline infusion, dissociation severity significantly reduced in subsequent infusions.

LIMITATIONS

This was a naturalistic, retrospective study, without a control group.

CONCLUSIONS

IV ketamine was safe, well-tolerated, and effective at improving depressive, anxiety, and functional impairment symptoms in a well-characterized cohort of adults with TRD.

The Psychopharmacology Algorithm Project at the Harvard South Shore Program: An update on bipolar depression

BACKGROUND

The Psychopharmacology Algorithm Project at the Harvard South Shore Program (PAPHSS) published algorithms for bipolar depression in 1999 and 2010. Developments over the past 9 years suggest that another update is needed.

METHODS

The 2010 algorithm and associated references were reevaluated. A literature search was conducted on PubMed for recent studies and review articles to see what changes in the recommendations were justified. Exceptions to the main algorithm for special patient populations, including those with attention-deficit hyperactivity disorder (ADHD), posttraumatic stress disorder (PTSD), substance use disorders, anxiety disorders, and women of childbearing potential, and those with common medical comorbidities were considered.

RESULTS

Electroconvulsive therapy (ECT) is still the first-line option for patients in need of urgent treatment. Five medications are recommended for early usage in acute bipolar depression, singly or in combinations when monotherapy fails, the order to be determined by considerations such as side effect vulnerability and patient preference. The five are lamotrigine, lurasidone, lithium, quetiapine, and cariprazine. After trials of these, possible options include antidepressants (bupropion and selective serotonin reuptake inhibitors are preferred) or valproate (very small evidence-base). In bipolar II depression, the support for antidepressants is a little stronger but depression with mixed features and rapid cycling would usually lead to further postponement of antidepressants. Olanzapine+fluoxetine, though Food and Drug Administration (FDA) approved for bipolar depression, is not considered until beyond this point, due to metabolic side effects. The algorithm concludes with a table of other possible treatments that have some evidence.

CONCLUSIONS

This revision incorporates the latest FDA-approved treatments (lurasidone and cariprazine) and important new studies and organizes the evidence systematically.

Blood pressure safety of subanesthetic ketamine for depression: A report on 684 infusions

BACKGROUND

The dissociative anesthetic agent ketamine is increasingly being utilized to treat depression, despite not having FDA (Food and Drug Administration) approval for this indication. There are many questions about the potential risks of this treatment and hence the proper setting and degree of monitoring required to ensure patient safety. There is limited data about the cardiovascular safety of ketamine when administered at subanesthetic doses to treat depression.

METHODS

66 patients in the Department of Psychiatry at Emory University received a total of 684 ketamine infusions between 2014 and 2016. Ketamine was dosed at 0.5 mg/kg body weight and infused over 40 min. Blood pressure was measured every 10 min during the infusions and every 15 min thereafter.

RESULTS

Mean age of the patients was 56.7 years, 87.9% had unipolar depression and 36.1% had essential hypertension. No infusions were discontinued due to instability of vital signs, adverse physiological consequences or acute psychotomimetic effects. The biggest increases in blood pressure were measured at 30 min (systolic 3.28 mmHg, diastolic 3.17 mmHg). Hypertensive patients had higher blood pressure peaks during the infusions. Blood pressures returned to baseline during post-infusion monitoring. There was no development of tolerance to the blood pressure elevating effects of ketamine between the first and sixth infusions.

LIMITATIONS

This is a single site, retrospective analysis, of patients who were spontaneously seeking clinical care.

CONCLUSIONS

The blood pressure changes observed when ketamine is administered over 40 min at 0.5 mg/kg for the treatment of depression are small, well tolerated and clinically insignificant.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Chronic Pain From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Over the past 2 decades, the use of intravenous ketamine infusions as a treatment for chronic pain has increased dramatically, with wide variation in patient selection, dosing, and monitoring. This has led to a chorus of calls from various sources for the development of consensus guidelines.

METHODS

In November 2016, the charge for developing consensus guidelines was approved by the boards of directors of the American Society of Regional Anesthesia and Pain Medicine and, shortly thereafter, the American Academy of Pain Medicine. In late 2017, the completed document was sent to the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters, after which additional modifications were made. Panel members were selected by the committee chair and both boards of directors based on their expertise in evaluating clinical trials, past research experience, and clinical experience in developing protocols and treating patients with ketamine. Questions were developed and refined by the committee, and the groups responsible for addressing each question consisted of modules composed of 3 to 5 panel members in addition to the committee chair. Once a preliminary consensus was achieved, sections were sent to the entire panel, and further revisions were made. In addition to consensus guidelines, a comprehensive narrative review was performed, which formed part of the basis for guidelines.

RESULTS

Guidelines were prepared for the following areas: indications; contraindications; whether there was evidence for a dose-response relationship, or a minimum or therapeutic dose range; whether oral ketamine or another N-methyl-D-aspartate receptor antagonist was a reasonable treatment option as a follow-up to infusions; preinfusion testing requirements; settings and personnel necessary to administer and monitor treatment; the use of preemptive and rescue medications to address adverse effects; and what constitutes a positive treatment response. The group was able to reach consensus on all questions.

CONCLUSIONS

Evidence supports the use of ketamine for chronic pain, but the level of evidence varies by condition and dose range. Most studies evaluating the efficacy of ketamine were small and uncontrolled and were either unblinded or ineffectively blinded. Adverse effects were few and the rate of serious adverse effects was similar to placebo in most studies, with higher dosages and more frequent infusions associated with greater risks. Larger studies, evaluating a wider variety of conditions, are needed to better quantify efficacy, improve patient selection, refine the therapeutic dose range, determine the effectiveness of nonintravenous ketamine alternatives, and develop a greater understanding of the long-term risks of repeated treatments.

NMDA Antagonists for Treatment-Resistant Depression

Fifteen to thirty percent of patients with major depressive disorder do not respond to antidepressants that target the monoaminergic systems. NMDA antagonists are currently being actively investigated as a treatment for these patients. Ketamine is the most widely studied of the compounds. A brief infusion of a low dose of this agent produces rapid improvement in depressive symptoms that lasts for several days. The improvement occurs after the agent has produced its well characterized psychotomimetic and cognitive side effects. Multiple infusions of the agent (e.g., 2-3× per week for several weeks) provide relief from depressive symptoms, but the symptoms reoccur once the treatment has been stopped. A 96-h infusion of a higher dose using add-on clonidine to mitigate the psychotomimetic effects appears to also provide relief and resulted in about 40% of the subjects still having a good response 8 weeks after the infusion. As this was a pilot study, additional work is needed to confirm and extend this finding. Nitrous oxide also has had positive results. Of the other investigational agents, CERC-301 and rapastinel remain in clinical development. When careful monitoring of neuropsychiatric symptoms has been conducted, these agents all produce similar side effects in the same dose range, indicating that NMDA receptor blockade produces both the wanted and unwanted effects. Research is still needed to determine the appropriate dose, schedule, and ways to mitigate against unwanted side effects of NMDA receptor blockade. These hurdles need to be overcome before ketamine and similar agents can be prescribed routinely to patients.

Ketamine treatment for depression: opportunities for clinical innovation and ethical foresight

We present a review and analysis of the ethical considerations in off-label ketamine use for severe, treatment-resistant depression. The analysis of ethical considerations is contextualised in an overview of the evidence for ketamine use in depression, and a review of the drug's safety profile. We find that, based on current evidence, ketamine use for severe, treatment-resistant depression does not violate ethical principles; however, clinicians and professional bodies must take steps to ensure that guidelines for good practice are enacted, that all experimental and trial data are made available through national registries, and that the risk potential of ketamine treatment continues to be monitored and modelled. We conclude with a set of key recommendations for oversight bodies that would support safe, effective, and ethical use of ketamine in depression.