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.

Psychological and neuropsychiatric implications of COVID-19

COVID-19 infections have spread quickly, resulting in massive healthcare burden to societies worldwide. The most urgent interventions needed in the present climate include epidemiological measures to reduce the spread of infection, efficient treatment of patients with severe illness to reduce mortality rates, as well as development of diagnostic tests. Alongside this, the acute, medium, and long-term mental-health consequences of the COVID-19 outbreak for patients, their family members, medical professionals, and the public at large should not be underestimated. Here, we draw on evidence from previous coronavirus outbreaks (i.e., SARS, MERS) and emerging evidence from China, Europe, Asia and the US to synthesize the current knowledge regarding the psychological and neuropsychiatric implications of the COVID-19 pandemic.

Charting the perfect storm: emerging biological interfaces between stress and stroke

A growing body of evidence demonstrates that psychosocial stress is an important and often underestimated risk factor for cardiovascular disease such as myocardial infarction and stroke. In this article, we map out major biological interfaces between stress, stress-related psychiatric disorders, and stroke, placing special emphasis on the fact that stress and psychiatric disorders may be both cause and consequence of cardiovascular disease. Apart from high-risk lifestyle habits such as smoking and lack of exercise, neuroendocrine dysregulation, alterations of the hemostatic system, increased oxidative stress, and inflammatory changes have been implicated in stress-related endothelial dysfunction. Heart rate provides another useful and easily available measure that reflects the complex interplay of vascular morbidity and psychological distress. Importantly, heart rate is emerging as a valuable predictor of stroke outcome and, possibly, even a target for therapeutic intervention. Furthermore, we review recent findings highlighting the role of FK506-binding protein 51 (FKBP5), a co-chaperone of the glucocorticoid receptor, and of perturbations in telomere maintenance, as potential mediators between stress and vascular morbidity. Finally, psychiatric sequelae of cardiovascular events such as post-stroke depression or posttraumatic stress disorder are highly prevalent and may, in turn, exert far-reaching effects on recovery and outcome, quality of life, recurrent ischemic events, medication adherence, and mortality.

Of mice and men: modelling post-stroke depression experimentally

At least one-third of stroke survivors suffer from depression. The development of comorbid depression after stroke is clinically highly significant because post-stroke depression is associated with increased mortality, slows recovery and leads to worse functional outcomes. Here, we review the evidence that post-stroke depression can be effectively modelled in experimental rodents via a variety of approaches. This opens an exciting new window onto the neurobiology of depression and permits probing potential underlying mechanisms such as disturbed cellular plasticity, neuroendocrine dysregulation, neuroinflammation, and neurodegeneration in a novel context. From the point of view of translational stroke research, extending the scope of experimental investigations beyond the study of short-term end points and, in particular, acute lesion size, may help improve the relevance of preclinical results to human disease. Furthermore, accumulating evidence from both clinical and experimental studies offers the tantalizing prospect of 5-hydroxytryptaminergic antidepressants as the first pharmacological therapy for stroke that would be available during the subacute and chronic phases of recovery. Interdisciplinary neuropsychiatric research will be called on to dissect the mechanisms underpinning the beneficial effects of antidepressants on stroke recovery.

[Post-stroke depression: clinical aspects, epidemiology, therapy, and pathophysiology]

Post-stroke depression (PSD) is the most frequent psychiatric complication following ischemic stroke, affecting up to 50% of all such patients. Moreover, PSD is associated with increased morbidity and mortality following ischemic stroke. In clinical practice, PSD is underdiagnosed and many affected patients do not receive adequate treatment. This review article summarizes current knowledge regarding epidemiogy, clinical features, risk factors and predisposition, therapy, and prophylaxis of PSD.

Randomized, double-blind study of SR142801 (Osanetant). A novel neurokinin-3 (NK3) receptor antagonist in panic disorder with pre- and posttreatment cholecystokinin tetrapeptide (CCK-4) challenges

OBJECTIVE

The present study was designed to examine the efficacy and tolerability of the non-peptide neurokinin-3 (NK3) receptor antagonist SR142801 in outpatients suffering from panic disorder.

METHODS

In a pilot study, 52 patients who were responders to a cholecystokinin tetrapeptide (CCK-4) challenge were randomized to four weeks of treatment with SR142801 (n = 36) or placebo (n = 16). Panic symptoms were assessed on weekly visits and a second CCK-4 challenge was performed at the end of the double-blind placebo controlled treatment period. Tolerability of SR142801 was generally good.

RESULTS

The proportion of patients who had at least one adverse event (AE) in the SR142801 group and the placebo group was similar (58.3 and 50 %, respectively). Independent of treatment group, patients' overall panic symptomatology was substantially improved at the end of the treatment.

CONCLUSION

With regard to efficacy of outcome, the compound was not significantly different from placebo. However, post-CCK-4 plasma prolactin concentrations showed a significant difference between placebo and SR142801.

In healthy volunteers responses to challenge with cholecystokinin tetrapeptide differ between administration during REM and delta sleep

This study was designed to examine the sensitivity of different sleep stages to the pharmacological provocation of nocturnal panic attacks by cholecystokinin tetrapeptide (CCK-4). In a balanced cross-over design, healthy participants were challenged with identical doses of CCK-4 both during REM sleep and during delta sleep. In nine subjects, stimulation with 50 microg CCK-4 during REM sleep failed to elicit a full-blown panic awakening, while the same dose, administered during delta sleep, produced full-blown panic attacks in two participants. Similarly, stimulation of six subjects with 100 microg CCK-4 during REM sleep resulted in only one panic response, whereas four of nine subjects awoke experiencing a panic attack following stimulation with the identical dose during delta sleep. Severity of panic symptomatology, as measured by the self-rated Acute Panic Inventory, was also significantly increased when CCK-4 was administered during delta sleep. CCK-4 can be used as a challenge agent with an abrupt onset of action making it possible to provoke panic attacks precisely during a particular sleep stage. Sensitivity to the panicogenic effects of CCK-4 seems to be higher during delta sleep than REM sleep.

Cardiac remodelling in experimental renal failure--an immunohistochemical study

BACKGROUND

In view of the high rate of cardiac death in renal failure, the factors involved in the genesis of structural changes in the heart are of obvious interest. The present study addresses the issue whether growth factors known to be involved in cardiac remodelling are abnormally expressed in rats with renal failure.

METHODS

Sprague Dawley rats were subjected to binephrectomy (2 days) or subtotal nephrectomy (8 weeks). Controls were sham-operated rats and rats with Goldblatt hypertension. Cardiac expression of proliferating cellular nuclear antigen (PCNA), of growth factors and of their receptors (PDGF, TGF-beta, VEGF) was investigated immunohistochemically. In addition, cardiac PDGF-and TGF-beta mRNA were assessed using quantitative RT-PCR.

RESULTS

Eight weeks after subtotal nephrectomy (SNX) significantly increased expression of PCNA and PDGF was found in the cardiac interstitium and of PCNA and VEGF in the walls of intramyocardial arteries. In addition, PCNA-positive cardiomyocytes were noted in SNX. Similar changes were not seen in the hearts of hypertensive controls, i.e. rats with renovascular hypertension, despite slightly higher blood pressure and more pronounced left ventricular hypertrophy (LVH). While significant changes of cardiac PDGF- and TGF-beta mRNA expression could not be documented in the whole-heart homogenates 8 weeks after subtotal nephrectomy, 2 days after bilateral nephrectomy PDGF mRNA was significantly increased and TGF-beta mRNA decreased.

CONCLUSION

The observations demonstrate (i) specific activation of cardiac interstitial cells after SNX, (ii) activation of postmitotic cardiomyocytes, possibly predisposing to apoptosis, (iii) increased expression of PDGF in the cardiac interstitium and in the wall of intramyocardial arteries, (iv) increased expression of VEGF associated with hypertrophy of arterial smooth muscle cells. These results were not explained by elevated blood pressure or LVH, respectively.