Cerebrospinal fluid exploratory proteomics and ketamine metabolite pharmacokinetics in human volunteers after ketamine infusion.

Ketamine is a treatment for both refractory depression and chronic pain syndromes. In order to explore ketamine's potential mechanism of action and whether ketamine or its metabolites cross the blood brain barrier, we examined the pharmacokinetics of ketamine and its metabolites-norketamine (NK), dehydronorketamine (DHNK), and hydroxynorketamines (HNKs)-in cerebrospinal fluid (CSF) and plasma, as well as in an exploratory proteomic analysis in the CSF of nine healthy volunteers who received ketamine intravenously (0.5 mg/kg IV). We found that ketamine, NK, and (2R,6R;2S,6S)-HNK readily crossed the blood brain barrier. Additionally, 354 proteins were altered in the CSF in at least two consecutive timepoints (p < 0.01). Proteins in the classes of tyrosine kinases, cellular adhesion molecules, and growth factors, including insulin, were most affected, suggesting an interplay of altered neurotransmission, neuroplasticity, neurogenesis, synaptogenesis, and neural network functions following ketamine administration.

Comparative metabolomic analysis in plasma and cerebrospinal fluid of humans and in plasma and brain of mice following antidepressant-dose ketamine administration.

Subanesthetic-dose racemic (R,S)-ketamine (ketamine) produces rapid, robust, and sustained antidepressant effects in major depressive disorder (MDD) and bipolar disorder (BD) and has also been shown to effectively treat neuropathic pain, complex regional pain syndrome, and post-traumatic stress disorder (PTSD). However, to date, its mechanism of action remains unclear. Preclinical studies found that (2 R,6 R;2 S,6 S)-hydroxynorketamine (HNK), a major circulating metabolite of ketamine, elicits antidepressant effects similar to those of ketamine. To help determine how (2 R,6 R)-HNK contributes to ketamine's mechanism of action, an exploratory, targeted, metabolomic analysis was carried out on plasma and CSF of nine healthy volunteers receiving a 40-minute ketamine infusion (0.5 mg/kg). A parallel targeted metabolomic analysis in plasma, hippocampus, and hypothalamus was carried out in mice receiving either 10 mg/kg of ketamine, 10 mg/kg of (2 R,6 R)-HNK, or saline. Ketamine and (2 R,6 R)-HNK both affected multiple pathways associated with inflammatory conditions. In addition, several changes were unique to either the healthy human volunteers and/or the mouse arm of the study, indicating that different pathways may be differentially involved in ketamine's effects in mice and humans. Mechanisms of action found to consistently underlie the effects of ketamine and/or (2 R,6 R)-HNK across both the human metabolome in plasma and CSF and the mouse arm of the study included LAT1, IDO1, NAD+, the nitric oxide (NO) signaling pathway, and sphingolipid rheostat.

Exposure to valproic acid is associated with less pulmonary infiltrates and improvements in diverse clinical outcomes and laboratory parameters in patients hospitalized with COVID-19.

BACKGROUND: Valproic acid (VPA) has shown beneficial effects in vitro against SARS-CoV-2 infection, but no study has analyzed its efficacy in the clinical setting. METHODS: This multicenter, retrospective study included 165 adult patients receiving VPA at the time of admission to hospital, and 330 controls matched for sex, age and date of admission. A number of clinical, outcome and laboratory parameters were recorded to evaluate differences between the two groups. Four major clinical endpoints were considered: development of lung infiltrates, in-hospital respiratory worsening, ICU admissions and death. RESULTS: VPA-treated patients had higher lymphocyte (P<0.0001) and monocyte (P = 0.0002) counts, and lower levels of diverse inflammatory parameters, including a composite biochemical severity score (P = 0.016). VPA patients had shorter duration of symptoms (P<0.0001), were more commonly asymptomatic (P = 0.016), and developed less commonly lung infiltrates (65.8%/88.2%, P<0.0001), respiratory worsening (20.6%/30.6%, P = 0.019) and ICU admissions (6.1%/13.0%, P = 0.018). There was no difference in survival (84.8%/88.8%, P = 0.2), although death was more commonly related to non-COVID-19 causes in the VPA group (36.0%/10.8%, P = 0.017). The cumulative hazard for developing adverse clinical endpoints was higher in controls than in the VPA group for infiltrates (P<0.0001), respiratory worsening (P<0.0001), and ICU admissions (P = 0.001), but not for death (0.6). Multivariate analysis revealed that VPA treatment was independently protective for the development of the first three clinical endpoints (P = 0.0002, P = 0.03, and P = 0.025, respectively), but not for death (P = 0.2). CONCLUSIONS: VPA-treated patients seem to develop less serious COVID-19 than control patients, according to diverse clinical endpoints and laboratory markers.

Drug Development for Mental Illness: How Psychiatry Clinical Trial Sites are Meeting the Challenge of the COVID-19 Pandemic.

Objective: The goal was to review the impact of the COVID-19 pandemic on psychiatric drug development and clinical trials. Main Points of Discussion: Disruption of pharmaceutical industry- sponsored clinical trials for psychiatric disorders by the COVID-19 pandemic, prompted by concerns regarding the safety of trial participants and the feasibility of trial conduct, has adversely impacted psychiatric drug development. In response, psychiatry trial sites have modified clinical trials and adapted trial conduct, through the use of social distancing, personal protective equipment, laboratory testing, and remote assessments, to reduce the risks of COVID-19. We review the implications of these modifications for participant safety, safe trial conduct, and data integrity. Conclusion: Given these implications, ongoing communication and consultation are needed between trials sites, sponsors, and all other stakeholders to ensure continued progress in psychiatric drug development during the pandemic.

Can 'floating' predict treatment response to ketamine? Data from three randomized trials of individuals with treatment-resistant depression.

Ketamine has rapid-acting antidepressant properties but also potentially concerning transient dissociative side effects (SEs). Recent studies noted a positive correlation between treatment response to ketamine and general dissociative SEs, as well as "floating", a depersonalization SE (a subtype of the dissociative SEs). This analysis sought to determine whether floating mediates treatment response to ketamine. Data were pooled from three double-blind, crossover, placebo-controlled ketamine clinical trials across which 82 participants with treatment-resistant depression (TRD) (44 with bipolar depression and 38 with major depressive disorder) received placebo and ketamine (0.5 mg/kg) infusions. SEs were actively solicited in a standardized fashion before and after ketamine infusion. The hypothesis that a post-infusion experience of floating would mediate antidepressant response to ketamine was assessed at 230 min post-infusion and at Day 1. Montgomery-Asberg Depression Rating Scale (MADRS) total score was the dependent variable in a linear mixed effects model. Ketamine significantly decreased MADRS scores (p < 0.0001), but no relationship was detected between floating and MADRS score at either 230 min or Day 1 post-infusion. The hypothesized mediation effect of floating was also not detected at either 230 min or Day 1 post-infusion. Taken together, the findings do not support the hypothesis that ketamine's antidepressant effects are mediated by the dissociative depersonalization subtype SE of floating.

Comprehensive assessment of side effects associated with a single dose of ketamine in treatment-resistant depression.

BACKGROUND: Concerns about ketamine for treating depression include abuse potential and the occurrence of psychotomimetic effects. This study sought to comprehensively assess side effects (SEs) associated with a single subanesthetic-dose intravenous ketamine infusion. A secondary aim was to examine the relationship between Clinician-Administered Dissociative States Scale (CADSS) scores and dissociative symptoms reported on a comprehensive, clinician-administered SE questionnaire. METHODS: Data from 188 participants were pooled from four placebo-controlled, crossover ketamine trials and one open-label study (n = 163 with either treatment-resistant major depressive disorder or bipolar disorder and 25 healthy controls). SEs were actively solicited in a standardized fashion and monitored over the time-course of each study. Statistical analyses assessed the effect of drug (ketamine, placebo) on SEs and measured the relationship between CADSS total score and SEs contemporaneously endorsed during structured interviews. RESULTS: Forty-four of 120 SEs occurred in at least 5% of participants over all trials. Thirty-three of these 44 SEs were significantly associated with active drug administration (versus placebo). The most common SE was feeling strange/weird/loopy. Most SEs peaked within an hour of ketamine administration and resolved completely by two hours post-infusion. No serious drug-related adverse events or increased ketamine craving/abuse post-administration were observed. A positive correlation was found between dissociative SEs and total CADSS score. LIMITATIONS: The post-hoc nature of the analysis; the limited generalizability of a single subanesthetic-dose ketamine infusion; and the lack of formal measures to assess ketamine's cognitive, urological, or addictive potential. CONCLUSIONS: No long-lasting significant SEs occurred over the approximately three-month follow-up period.

The influence of ketamine on drug discovery in depression.

Recent research demonstrating that the glutamatergic modulator ketamine has rapid, robust, and sustained antidepressant effects has been a turning point in drug discovery for depression. The recent FDA approval of esketamine for adults with treatment-resistant major depressive disorder (MDD) has further underscored the relevance of this agent in spurring investigation into novel and mechanistically distinct agents for use in depression. Over the past two decades, ketamine research has ushered in a new wave of studies seeking to not only identify its mechanism of action but also to examine the antidepressant potential of novel or repurposed agents. This article reviews the approaches that have proven particularly fruitful for the field of neuropsychiatry.

First Report of New Delhi Metallo-ß-Lactamase Carbapenemase-Producing Acinetobacter baumannii in Peru.

Here we report the first incidence of New Delhi metallo-ß-lactamase (NDM-1)-producing Acinetobacter baumannii in Peru, identified via a strain-based nosocomial surveillance project carried out in Lima and Iquitos. The bla NDM-1 gene was detected by multiplex polymerase chain reaction (PCR) and confirmed by loci sequencing. Acinetobacter baumannii is a nearly ubiquitous and promiscuous nosocomial pathogen, and the acquisition of bla NDM-1 by A. baumannii may facilitate an increase in the prevalence of this important resistance marker in other nosocomial pathogens.

Challenges of managing delirium and catatonia in a medically ill patient.

BACKGROUND: Untangling catatonia and delirium can be challenging. Furthermore, treatment of one syndrome can potentially worsen another. CASE PRESENTATION: We present the case of a 71-year-old patient with a history of schizoaffective disorder, bipolar subtype, who developed catatonia and delirium with prominent psychotic symptoms, during a single hospitalization. Treatment of this patient's catatonia with benzodiazepines exacerbated delirium, while treatment of psychotic symptoms precipitated by delirium with antipsychotics led to catatonia. Catatonia and psychotic symptoms were eventually successfully managed with electroconvulsive therapy (ECT). DISCUSSION: This case report highlights some of the treatment challenges faced when delirium and catatonia overlap in a medically ill patient. The use of benzodiazepines, valproic acid, antipsychotics, ECT and alternate medications to treat catatonia are also discussed.