Background and Objectives: Options for treatment-resistant bipolar depression (TRBPD) are limited. Electroconvulsive therapy (ECT) has shown efficacy in TRBPD. However, the cognitive deficits and memory concerns associated with ECT are problematic for a significant number of patients. It remains unclear what the next step is for patients with TRBPD who fail ECT. Materials and Methods: In this case report, we present a patient with TRBPD who sequentially received 12 sessions of brief-pulse right unilateral ECT, 22 sessions of ketamine infusion at 0.5-0.75 mg/kg for 40 min, and 39 sessions of deep repetitive transcranial magnetic stimulation (dTMS). Results: The patient had some benefit from ECT, but declined continuation of ECT due to memory concerns. The patient tolerated ketamine infusion well but had limited benefit. However, the patient responded well to acute treatment with dTMS and maintained relative stability for more than 2 years. Conclusions: This case suggests that patients with TRBPD who fail ECT and/or ketamine infusion might benefit from dTMS.

UNASSIGNED: Replicated evidence indicates that ketamine and esketamine reduce measures of suicidality in persons with treatment-resistant depression (TRD). It remains uncertain whether individuals experience worsening of preexisting suicidality with either agent.
UNASSIGNED: The Food and Drug Administration Adverse Event Reporting System (FAERS) database was searched from 1970 and 2019 to 30 September 2023 for reports of suicidal ideation, depression suicidal, suicidal behavior, suicidal attempt, and completed suicide in association with ketamine and esketamine exposure, respectively. We present reporting odds ratios (ROR) significance was determined when the lower limit of the 95% confidence interval (CI) exceeded 1.0. Lithium was used as the control agent.
UNASSIGNED: Observed a higher ROR for suicidal ideation (ROR 7.58, 95% CI 6.34-9.07) and depression suicidal (ROR 14.19, 95% CI 1.80-112.07) with esketamine. Significantly lower RORs were observed for suicide attempt with ketamine (ROR 0.15, 95% CI 0.11-0.21) and esketamine (ROR 0.57, 95% CI 0.48-0.67).
UNASSIGNED: Mixed RORs across aspects of suicidality were observed with ketamine and esketamine. Limitations of the FAERS database prevent any determination of causal effects new onset suicidality to either agent. The lower RORs for suicide attempt with ketamine and esketamine is noted but cannot be interpreted as a direct therapeutic effect.

The turn of the century brought a resurgence of interest in psychedelics as a treatment for addiction and other psychiatric conditions, accompanied by extensive positive media attention and private equity investment. Government regulatory bodies in Australia, Israel, Canada and the United States now permit use of psychedelics for medical purposes. In the United States, citizen action and corporate financing have led to petitions and ballot initiatives to legalize psilocybin and other psychedelics for medical and recreational use. Given this momentum, policymakers must grapple with important questions that define whether and how psychedelics are made available to the public, as well as how companies produce and promote them. The current push to broaden the production, sale, and use of psychedelics bears many parallels to the movement to legalize cannabis in the United States and other nations-most notably, the use of poorly-evidenced therapeutic claims to create a de facto recreational market via the health care system. Experience with cannabis highlights the value of debating the question of legalization for nonmedical use as such rather than misrepresenting it as a medical issue. The lessons of cannabis policy also suggest a need to challenge hyping of psychedelic research findings; to promote rigorous clinical research on dosing and potency; to minimize the influence of for-profit industry in shaping policies to their economic advantage; and to coordinate federal, state, and local governments to regulate the manufacture, sale and distribution of psychedelic drugs (regardless of whether they are legalized for medical and/or recreational use).

Serotonin (5-HT) syndrome (SS) consists of changes in mental status as well as autonomic and neuromuscular changes. Though not well understood, serotonergic pathways have been implicated in the mechanism of action of electroconvulsive therapy (ECT). Ketamine has been used as an induction agent in ECT and as therapy for treatment-resistant depression. Utilizing a case report and literature review, we explored the underlying serotonergic mechanisms of ECT and ketamine by which a syndrome of serotonin toxicity may be precipitated. We describe the case of a 72-year-old woman who developed recurrent SS on 2 occasions in similar circumstances involving the administration of ketamine for ECT. In our literature review, we found 5 cases in which SS was associated with ECT and 1 case linking ketamine to SS. There is emerging evidence that the mechanism of ECT involves 5-HT1A and 5-HT2A receptors, the same receptors that are involved in SS. ECT can transiently increase the permeability of the blood-brain barrier, leading to increased levels of antidepressants in the brain. ECT can, therefore, enhance 5-HT transmission and the likelihood of SS in the presence of serotonergic agents. The effect of ketamine on 5-HT transmission is mediated by the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. Ketamine increases α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid activity in the medial prefrontal cortex, which leads to downstream 5-HT release through glutamate. Through this mechanism, ketamine can increase 5-HT transmission, leading to SS. To our knowledge, this is the only case report of recurrent SS with concurrent use of ECT and ketamine. As ketamine is frequently used in ECT and many patients undergoing ECT are on serotonergic medications, it is important to recognize ketamine as a potential risk factor for SS. There is no evidence for added efficacy when combining ECT and ketamine. Thus, one should proceed with caution when combining these treatments. The burgeoning use of ketamine in ambulatory settings makes it necessary to elucidate the risks, which we discuss further. More research is needed into the mechanisms of ketamine and ECT, specifically how the combination of these treatments influence 5-HT levels.

BACKGROUND: Intranasal esketamine is an approved drug for treatment‐resistant depression (TRD); however, it is costly and may result in specific adverse effects. In this single case study, we explored if oral esketamine can be a suitable alternative.
METHODS: In collaboration with a 39‐year‐old female with TRD, we compared plasma concentration curves of intranasal (84 mg) and oral (1, 2 and 4 mg/kg) esketamine. Because oral esketamine has a relatively low bioavailability, it results in a different ratio between esketamine and its primary metabolite noresketamine. To increase the bioavailability of oral esketamine, we co‐administered a single dose of the cytochrome P‐450 (CYP) 3A4 inhibitor cobicistat (150 mg).
RESULTS: For all doses administered, oral esketamine resulted in lower esketamine but higher noresketamine peak plasma concentrations compared with intranasal treatment. Using oral esketamine it was not possible to generate a similar esketamine plasma concentration curve as with the intranasal treatment, except when combined with cobicistat (esketamine 2 mg/kg plus cobicistat 150 mg).
CONCLUSIONS: Our findings demonstrate that cobicistat effectively increases the bioavailability of oral esketamine. Further research is required in a larger population, especially to investigate the clinical benefit of cobicistat as a booster drug for oral esketamine.

暂无摘要。

BACKGROUND: Ketamine and esketamine have been proven to be effective in treating adults with treatment resistant depression (TRD). Preliminary evidence indicates that, when combined with behavioral and psychological interventions, both agents may offer benefits for individuals with substance use disorder (SUD) and alcohol use disorder (AUD). Notwithstanding, concerns have been raised as to whether either or both agents are associated with abuse and/or gateway activity.
METHODS: Herein, we evaluate disproportionate reporting expressed as reporting odds ratios (ROR) for esketamine and ketamine. The outcomes of interest include alcohol problem, alcoholism, alcohol abuse, substance dependence, SUD, substance abuse, drug dependence, drug use disorder and drug abuse as codified by the Medical Dictionary for Regulatory Activities (MedDRA) within the FAERS. The IC025 values were significant for ketamine in cases of alcohol abuse (0.28), substance dependence (1.88), substance use disorder (0.996), substance abuse (0.61), drug dependence (0.56), drug use disorder (1.17) and drug abuse (1.22). Additionally, oxycontin showed significant IC025 values for substance dependence (0.067), substance use disorder (0.094), substance abuse (0.035), and drug dependence (0.27).
RESULTS: We observed significant increases in the reporting odds ratios (RORs) for ketamine with respect to various outcomes: alcohol abuse (ROR 2.84, 95 % CI 1.53-5.28; p = 0.0010), substance dependence (ROR 18.72, 95 % CI 8.49-41.30; p ≤ 0.0001), SUD (ROR 11.40, 95 % CI 4.24-30.65; p ≤ 0.0001), substance abuse (ROR 2.29, 95 % CI 1.73-3.04; p ≤ 0.0001), drug dependence (ROR 1.99, 95 % CI 1.64-2.42; p ≤ 0.0001), drug use disorder (ROR 4.50, 2.94-6.88; p ≤ 0.0001) and drug abuse (ROR 3.72, 3.36-4.12; p ≤ 0.0001). For esketamine, we observed that the ROR was significantly reduced for substance abuse (ROR 0.37, 95 % CI 0.22-0.63; p = 0.0003), drug dependence (ROR 0.13, 95 % CI 0.076-0.23; p ≤ 0.0001) and drug abuse (ROR 0.048, 95 % CI 0.030-0.078; p ≤ 0.0001). To our knowledge, this is the first report of spontaneous adverse events related to these outcomes of interest in the FAERS.
CONCLUSIONS: Mixed RORs were observed across aspects of SUD and AUD for both ketamine and esketamine. Due to limitations in the FAERS, establishing causal links between new onset alcohol and substance misuse with either agent remains inconclusive. Possible beneficial effects on measures of SUD and AUD were observed. It is currently unclear, but possible, whether both agents have differential ameliorative effects across dimensions of SUD and AUD, which is a focus of ongoing research.

BACKGROUND: Cluster headache is a severe and debilitating neurological condition characterized by intense, excruciating pain with a significant impact on patients\' wellbeing. Although different treatment options are available, many patients continue to experience inadequate relief. Therefore, experimental strategies are increasingly studied. One of the more promising approaches is the use of ketamine. We present the currently available evidence and our own data.
METHODS: In this mixed-methods paper, we first summarize the available evidence of ketamine for treatment of cluster headache based on a systematic review of literature in MEDLINE, EMBASE and the Cochrane library of systematic reviews. As the level of evidence is quite limited, we report our own cohort study with ten patients treated with ketamine infusions for cluster headache. They were followed up to investigate the patients\' experience of treatment success and quality of life.
RESULTS: The search and review of literature identified four reports with a total of 68 patients. All were uncontrolled case series. The current literature suggests that ketamine might decrease cluster headache. However, as the applied regimes and reported outcomes are highly heterogeneous, further analysis was futile. Our own data show high patient satisfaction with ketamine treatment.
CONCLUSIONS: Despite the limited evidence, ketamine might be considered a potential therapeutic approach for cluster headache. Therefore, further research including randomized controlled trials should be encouraged.
This article discusses the potential use of ketamine for the treatment of cluster headache, a severe neurological condition that can have a significant impact on patients\' quality of life. The authors conducted a systematic review of the existing literature on ketamine for the treatment of cluster headache. Additionally, they also presented their own cohort study of ten patients receiving ketamine infusions. The review of the literature revealed four reports with a total of 68 patients, all of which were uncontrolled case series. While the current literature suggests that ketamine may be effective in relieving cluster headache symptoms, the heterogeneity of treatment regimens and reported outcomes makes it difficult to draw definitive conclusions. The authors\' own cohort study found that patients were very satisfied with ketamine treatment, indicating a potential benefit of this approach. However, due to the limited evidence available, further research, including randomized controlled trials, is needed to better understand the efficacy of ketamine in the treatment of cluster headaches.

BACKGROUND: Access to anaesthesia and surgical care is a major problem for people living in Sub-Saharan Africa. In this region, ketamine is critical for the provision of anaesthesia care. However, efforts to control ketamine internationally as a controlled substance may significantly impact its accessibility. This research therefore aims to estimate the importance of ketamine for anaesthesia and surgical care in Sub-Saharan Africa and assess the potential impact on access to ketamine if it were to be scheduled.
METHODS: This research is a mixed-methods study, comprising of a cross-sectional survey at the hospital level in Rwanda, and key informant interviews with experts on anaesthesia care in Sub-Saharan Africa. Data on availability of four anaesthetic agents were collected from hospitals (n = 54) in Rwanda. Semi-structured interviews with 10 key informants were conducted, collecting information on the importance of ketamine, the potential impact of scheduling ketamine internationally, and opinions on misuse of ketamine. Interviews were transcribed verbatim and analysed using a thematic analysis approach.
RESULTS: The survey conducted in Rwanda found that availability of ketamine and propofol was comparable at around 80%, while thiopental and inhalational agents were available at only about half of the hospitals. Significant barriers impeding access to anaesthesia care were identified, including a general lack of attention given to the specialty by governments, a shortage of anaesthesiologists and migration of trained anaesthesiologists, and a scarcity of medicines and equipment. Ketamine was described as critical for the provision of anaesthesia care as a consequence of these barriers. Misuse of ketamine was not believed to be an issue by the informants.
CONCLUSIONS: Ketamine is critical for the provision of anaesthesia care in Sub-Saharan Africa, and its scheduling would have a significantly negative impact on its availability for anaesthesia care.

We report a case of a 62-year-old woman with a decade-long history of atypical chest pain resulting in a largely negative cardiac workup, who developed significant angiographically demonstrated coronary vasospasm thought to be due to a small dose of intravenous ketamine. In patients with a history of atypical chest pain despite a reassuring cardiac evaluation, providers should carefully consider medications that may precipitate coronary vasospasm and be prepared to treat it accordingly.