Противосудорожный препарат ламотригин может дать начало новому классу антибиотиков — ингибиторам сборки бактериальных рибосом

В связи с растущей проблемой антибиотикорезистентнтности активно ведутся поиски новых антибактериальных препаратов, действующих как уже на известные «мишени», так на структуры бактериальной клетки, ранее не являвшиеся мишенью действия антибиотиков. Причём если ранее в основном пытались ингибировать важнейшие процессы жизнедеятельности микроорганизмов, то сейчас рассматриваются и варианты воздействия на построение (сборку) отдельных структур микробной клетки.

Исследователями был проведён скрининг большого числа уже применяющихся в клинической практике лекарственных средств на наличие зависимой от температуры способности ингибировать рост Escherichia coli. Одним из препаратов, активность которого наиболее выраженно уменьшалась при снижении температуры, был давно применяющийся противосудорожный препарат ламотригин. В присутствии ламотригина в микробных клетках быстро возрастала концентрация незрелых 30S и 50S субъединиц рибосом. При этом препарат не нарушал процесс трансляции и непосредственно не влиял на синтез белков in vitro и in vivo. Таким образом, ламотригин может стать первым представителем целого нового класса антибактериальных препаратов — ингибиторов сборки бактериальных рибосом.

Однако, несмотря на очевидную перспективность разработки антибиотиков с новыми механизмами действия, вероятность развития к ним устойчивости также возможна. В частности, ряд спонтанных мутаций в домене II фактора инициации трансляции IF2 блокируют присоединение ламотригина к IF2 и, соответственно, нивелируют активность данного препарата в отношении процесса сборки бактериальных рибосом.

 Противосудорожный препарат ламотригин может дать начало новому классу антибиотиков — ингибиторам сборки бактериальных рибосом

Влияние энергетической ценности пищи на биодоступность зипрасидона и луразидона

It is interesting to note that ziprasidone and lurasidone are the only psychiatric medications with specific calorie requirements to aid absorption. The precise mechanism is still unknown. The package insert for ziprasidone recommends concomitant intake with food, which provides an up to 2-fold increase in absorption. More specifically, a clinical trial that evaluated the effects of different caloric and fat content on ziprasidone systemic exposure showed that a meal with 500 kcal or more (irrespective of fat content) is required for optimal bioavailability.

The package insert for lurasidone recommends concomitant intake with 350 kcal or more, because lurasidone Cmax and AUC are increased approximately 3- and 2-fold, respectively, compared with fasting condi-tions. (Lurasidone exposure was not affected as calorie content was increased from 350 to 1000 kcal and was independent of meal fat content.)

Food-Drug Interactions in Psychiatry: What Clinicians Need to Know

Антипсихотические свойства варфарина

Warfarin has been linked to a decrease in and even long-term remission of psychotic symptoms in patients with schizophrenia, preliminary research suggests.
A study examining adults at an anticoagulation clinic for deep venous thrombosis (DVT) showed that 5 patients who also had schizophrenia and who received long-term treatment with warfarin for recurrent DVT achieved full psychosis remission. In addition, these patients remained free of any psychotropic medication for 2 to 11 years.
The investigators note that the underlying mechanism could be tissue-plasminogen activator (tPA), a protein that not only promotes the dissolution of blood clots but also plays a role in neurogenesis after severe stress.

Warfarin for Long-term Psychosis Remission?

Эффективность битопертина не подтвердилась

FlashLyte and DayLyte, the first 2 studies discontinued in January 2014, were evaluating bitopertin for negative symptoms, including lack of motivation and social withdrawal. Suboptimally controlled symptoms include hallucinations and delusions.

The primary endpoints were negative symptom factors scores on the Positive and Negative Symptom Scale (PANSS) after 24 weeks of adjunctive treatment with bitopertin vs placebo. Although the active treatment was found to be well tolerated, the PANSS score changes from baseline were not found to be statistically significant.

Bitopertin Disappoints as Schizophrenia Treatment

Оланзапин превзошел ламотриджин в профилактике депрессивной фазы биполярного аффективного расстройства

Background

Bipolar disorder is a highly recurrent disease and has great impact on the function of patients. Depressive symptoms consist of more than 50% of life time during the illness and may lead to self harm or suicidal behaviors. Little is known about the antidepressant effects of olanzapine, an atypical antipsychotic, as monotherapy despite its indication for preventing manic episodes. In contrast, lamotrigine, a mood stabilizer, has been proven to be effective in preventing depression in patients with bipolar disorder. However, no studies have compared the efficacy between lamotrigine and olanzapine in the maintenance treatment of bipolar disorder. This enriched naturalistic study was implemented to assess the effectiveness of olanzapine and lamotrigine as monotherapy in the prevention of recurrence of bipolar disorder.

Methods

Patients with bipolar disorder in a euthymic state (Young's Mania Rating Scale (YMRS) score < 12, and 21-item Hamilton Depression Rating Scale (HAM-D) score < 7) for at least two months, having already received either olanzapine or lamotrigine as the maintenance treatment were recruited. The patients maintained with olanzapine (n = 22) were applied to olanzapine group whereas those maintained with lamotrigine (n = 29) were applied to lamotrigine group. They were followed up for 12 months. Differences in the efficacy between olanzapine and lamotrigine in recurrence prevention were analyzed. The Kaplan-Meier method was used to generate time-to-recurrence curves, and differences between the two groups were compared using the log-rank test.

Results

Olanzapine had a significantly lower recurrence rate of depressive episodes than lamotrigine (20.0% vs. 57.7%, chi2 = 6.62, p = .010). However, olanzapine and lamotrigine had similar mania (15.0% vs. 0%, chi2 = 4.17, p = .075, Fisher's exact test) and any mood episode (35.0% vs. 57.7%, chi2 = 2.33, p = .127) recurrence rates. Olanzapine was significantly superior to lamotrigine in the time to recurrence of depressive episodes (chi2 = 4.55, df = 1, p = .033), but there was no difference in the time to recurrence of any mood episode (chi2 = 1.68, df = 1, p = .195).

Conclusions

This prospective naturalistic study suggests that olanzapine is more effective than lamotrigine in the prevention of depressive episodes in patients with bipolar disorder. Future large-scale randomized studies are warranted to validate our results.

 Olanzapine is superior to lamotrigine in the prevention of bipolar depression: a naturalistic observational study

Эйкозапентаеновая кислота как корректор интерферон-индуцированной депрессии

Background

Interferon (IFN)-α therapy for chronic hepatitis C virus infection is frequently associated with depression. The routine prophylaxis with antidepressants might expose patients to adverse effects, hence, the need for alternative preventive interventions. Omega-3 polyunsaturated fatty acids are safe and effective essential nutritional compounds used for the treatment of depression, putatively through an anti-inflammatory action. In addition, lower erythrocyte levels of omega-3 polyunsaturated fatty acids have been associated with an increased risk of IFN-induced depression.

Methods

We conducted a 2-week, double-blind, placebo-controlled trial comparing eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and placebo for the prevention of IFN-α-induced depression. A total of 162 patients consented to participate and were randomized to the study. All of the patients completed the 2-week trial; 152 participants were followed throughout the 24 weeks of IFN-α treatment and were included in the analysis.

Results

Compared with placebo, the incident rates of IFN-α-induced depression were significantly lower in EPA-treated but not in DHA-treated patients (10% and 28%, respectively, versus 30% for placebo, p = .037). Both EPA and DHA significantly delayed the onset of IFN-induced depression (week of onset: 12.0 and 11.7, respectively, versus 5.3 for placebo, p = .002). EPA and DHA were both well tolerated in this population. EPA treatment increased both EPA and DHA erythrocyte levels, but DHA only increased DHA erythrocyte levels.

Conclusions

EPA is effective in the prevention of depression in hepatitis C virus patients received IFN-α therapy. Our study confirms the notion that anti-inflammatory strategies are effective antidepressants in the context of depression associated with inflammation.

Omega-3 Fatty Acids in the Prevention of Interferon-Alpha-Induced Depression: Results from a Randomized, Controlled Trial 

Акампросат, механизм действия

Throughout the years, however, the molecular target of acamprosate has remained elusive. Because of structural similarities, initial hypotheses centered on the possibility that acamprosate may act as a GABA-mimic or otherwise modulate GABA-ergic transmission. There is, however, little in the in vivo profile of acamprosate to suggest similarities with drugs known to enhance GABA-ergic transmission. In fact, a lack of sedative–ataxic or addictive properties is among the clinical advantages of acamprosate. Once it became clear that acamprosate’s mechanism of action is likely to involve modulation of glutamatergic function, several potential mechanisms were explored. For instance, acamprosate was shown to possess some partial agonist activity on the NMDA receptor complex via actions at its polyamine site. This would potentially allow it to act as a functional antagonist during hyperglutamatergic states. However, experiments failed to demonstrate this kind of functional activity. More recently, focus shifted to potential activity of acamprosate at metabotropic glutamate receptors (mGluRs). This was prompted, for example, by observations that acamprosate blocked neurotoxicity induced by trans-ACPD, an mGluR agonist with affinity for mGluR1 and mGluR5 receptors (Kiefer and Mann, 2010).

Over the years, the notion has become widely accepted that, although we may not know its exact mechanism of action, acamprosate is ‘a functional glutamate antagonist’. The paper by Spanagel et al (2005) in this issue fundamentally challenges this notion. The paper presents multiple lines of evidence that the reason it has been difficult to pin down the molecular site of acamprosate action may simply be because it does not exist. Instead, the authors propose that the activity attributed to acamprosate has all along reflected actions of the Ca++ it carries. The authors first thoroughly excluded agonist as well as antagonist activity of acamprosate at the glycine or glutamate sites of the NMDA receptor, respectively, as well as at the mGluR5 receptor. They then went on to demonstrate in vivo that, in contrast to the Ca++ salt, the sodium salt of acamprosate did not suppress relapse-like drinking. Conversely, the delivery of comparable amounts of Ca++ using a different carrier, gluconate, replicated suppression of relapse-like drinking. These animal findings are supported by secondary analyses of clinical trial data, which indicate that in acamprosate-treated patients positive outcomes are strongly correlated with plasma Ca++ levels. No such correlation exists in placebo-treated patients.

Acamprosate: An Alcoholism Treatment That May Not Be What We Thought

Перспективные методы лечения депрессий

Long-term stress harms cells in the brain and body. Stressful experiences are believed to be closely associated with the development of psychological alterations and, thus, neuropsychiatric disorders.
In conditions of chronic stress exposure, nerve cells in the hippocampus begin to atrophy. (The hippocampus is a part of the brain involved with emotions, learning, and memory formation.)
The new depression theories “should not be viewed as separate entities because they are highly interconnected,” researchers write.
“Integrating them provides for a more expansive understanding of the pathophysiology of depression and biomarkers that are involved.”
Such biomarkers are molecules in the body that can be indicators of depression. The authors identify more than a dozen potential biomarkers depression, including monoamine regulators; proinflammatory cytokines and other inflammatory mediators; mediators of glutaminergic activity and GABAergic activity; and regulators of neurogenesis.
A bevy of new depression treatments are currently offered or on the horizon include corticotropin-releasing hormone antagonists; dexamethasone; partial adrenalectomy; long-term cognitive behavioral therapy; ketamine and other NMDA antagonists. Other treatments include benzodiazepines; anesthetics; deep brain stimulation; transcranial magnetic stimulation; exogenous brain-derived neurotrophic factor; selective serotonin reuptake inhibitors; tricyclic antidepressants; atypical antidepressants; reduction in inflammation; and anti-inflammatory drugs.

 Beyond Antidepressants: Taking Stock of New Treatments

Антидепрессивный эффект стимуляции NMDA функции схож с эффектом кетамина

Philadelphia, PA, November 18, 2013– Thirteen years ago, an article in this journal first reported that the anesthetic medication, ketamine, showed evidence of producing rapid antidepressant effects in depressed patients who had not responded to prior treatments. Ketamine works by blocking one of the targets for the neurotransmitter glutamate in the brain, the N-methyl-D-aspartate (NMDA) glutamate receptor.

Now, a new study in Biological Psychiatry reports that enhancing, instead of blocking, that same target – the NMDA glutamate receptor – also causes antidepressant-like effects.

Scientists theorize that NMDA receptor activity plays an important role in the pathophysiology of depression, and that normalizing its functioning can, potentially, restore mood to normal levels.

Prior studies have already shown that the underlying biology is quite complex, indicating that both hyperfunction and hypofunction of the NMDA receptor is somehow involved. But, most studies have focused on antagonizing, or blocking, the receptor, and until now, studies investigating NMDA enhancement have been in the early phases.

Sarcosine is one such compound that acts by enhancing NMDA function. Collaborators from China Medical University Hospital in Taiwan and the University of California in Los Angeles studied sarcosine in an animal model of depression and, separately, in a clinical trial of depressed patients.

“We found that enhancing NMDA function can improve depression-like behaviors in rodent models and in human depression,” said Dr. Hsien-Yuan Lane, the corresponding author on the article.

In the clinical portion of the study, they conducted a 6-week trial where 40 depressed patients were randomly assigned to receive sarcosine or citalopram (Celexa), an antidepressant already on the market that was used as a comparison drug. Neither the patients nor their doctors knew which one they were receiving.

Compared to citalopram, patients receiving sarcosine reported significantly improved mood scores, were more likely to experience relief of their depression symptoms, and were more likely to continue in the study. There were no major side effects in either group, but patients receiving citalopram reported more relatively minor side effects than the patients being treated with sarcosine.

“It will be important to understand how sarcosine, which enhances NMDA receptor function, produces the interesting effects reported in this study. There are ways that its effects, paradoxically, might converge with those of ketamine, a drug that blocks NMDA receptors,” commented Dr. John Krystal, Editor of Biological Psychiatry. “For example, both compounds may enhance neuroplasticity, the capacity to remodel brain networks through experience. Also, both potentially attenuate signaling through NMDA receptors, ketamine with single doses and sarcosine, with long-term administration, by evoking an adaptive down regulation of NMDA receptors.”

Would an “Anti-Ketamine” Also Treat Depression? 

Мета-анализ: добавление НПВС к терапии антипсихотиками при шизофрении

Objective: To meta-analytically assess the efficacy and tolerability of nonsteroidal anti-inflammatory drugs (NSAIDs) vs placebo in schizophrenia. Method: Searching PubMed, PsycINFO, ISI Web of Science, and the US National Institute of Mental Health clinical trials registry from database inception to December 31, 2012, we conducted a systematic review/meta-analysis of randomized placebo-controlled studies assessing the efficacy of adjunctive NSAIDs. Primary outcome was the change in Positive and Negative Syndrome Scale (PANSS) total score. Secondary outcomes included change in PANSS positive and negative subscores, all-cause discontinuation, and tolerability outcomes. Random effects, pooled, standardized mean changes (Hedges’ g) and risk ratios were calculated. Results: Across 8 studies, including 3 unpublished reports (n = 774), the mean effect size for PANSS total score was −0.236 (95% CI: −0.484 to 0.012, P = .063, I2 = 60.6%), showing only trend-level superiority for NSAIDs over placebo. The mean effect sizes for the PANSS positive and negative scores were −0.189 (95% CI: −0.373 to −0.005, P = .044) and −0.026 (95% CI: −0.169 to 0.117, P = .72), respectively. The relative risk for all-cause discontinuation was 1.13 (95% CI: 0.794 to 1.599, P = .503). Significant superiority of NSAIDs over placebo regarding PANSS total scores was moderated by aspirin treatment (N = 2, P = .017), inpatient status (N = 4, P = .029), first-episode status (N = 2, P = .048), and (in meta-regression analyses) lower PANSS negative subscores (N = 6, P = .026). Interpretation: These results indicate that adjunctive NSAIDs for schizophrenia may not benefit patients treated with first-line antipsychotics judged by PANSS total score change. NSAIDs may have benefits for positive symptoms, but the effect was minimal/small. However, due to a limited database, further controlled studies are needed, especially in first-episode patients.

 Adjunctive Use of Nonsteroidal Anti-inflammatory Drugs for Schizophrenia: A Meta-analytic Investigation of Randomized Controlled Trials

Роль воспалительных процессов в формировании резистентности к лечению депрессии

Inflammation may also be relevant to depression prevention and relapse. There are multiple clinical factors associated with both inflammation and TRD that can be addressed through lifestyle changes. Treating obesity with diet and exercise in patients with increased inflammation is a primary example. In a recent clinical trial of partial treatment responders, depressed patients with increased TNF levels were more likely to respond to an add-on exercise intervention than were patients who were partially responsive to an SSRI. Another consideration is behavioral stress management including compassion meditation training, which has been shown to reduce inflammatory responses to a laboratory psychosocial stressor.

Exercise and meditation have been associated with an increased parasympathetic tone, which, in turn, has been associated with decreased inflammatory tone. These effects are likely related to parasympathetic activation of T cells that produce acetylcholine that binds to the α subunit of the nicotinic acetylcholine receptor, leading to inhibition of NF-κB.41 Finally, optimizing the management of medical illnesses associated with inflammation may also reduce depression symptoms and improve treatment response.

Inflammation and Treatment Resistance in Major Depression: The Perfect Storm

Возможные механизмы антидепрессивного действия антипсихотиков второго поколения

Although the exact mechanism of SGAs for MDD has not yet been clearly elucidated, several plausible underlying mechanisms are listed as follows: modulation of crucial neurotransmitter receptors and transporters such as dopamine, serotonin and noreinephrine resulting in net effect of enhancement of such neurotransmitters' transmission, effects on sleep, alteration of various hormones (ACTH, sex hormones, etc.), modification of immune functions including modulation of inflammation process (cytokines, etc.), antioxidation process and modulation of neurotrophic factors (BDNF, etc).[13]

Specifically, the main pharmacological rationale of SGAs as an antidepressant augmentation would be based on their effects on monoamine transporters or receptors of crucial neurotransmitters such as serotonin, norepinephrine and dopamine, which are also the main target of contemporary antidepressants. The partial agonism at D2 and/or D3 receptors may increase dopamine neurotransmission at the prefrontal cortex. The increase in the dopamine concentration in the prefrontal cortex may be also indirectly related to the antidepressive effect of 5-HT1A receptor agonist.[14,15] The antidepressant effect may also be mediated by 5-HT1A partial agonism and/or antagonism at 5-HT2A receptors.[16–18] Although, still controversial, the antidepressant effect of 5-HT1A receptor agonists may be predominantly mediated by postsynaptic 5-HT1A receptors, while the anxiolytic effect would be mainly associated with presynptic 5-HT1A receptors.[19] The antagonism of the 5-HT2C receptors has been also found to be involved in increased dopamine and norepinephrine transmission.[20] It is also well known that high affinity at the α2-adrenergic receptor may enhance the release of norepinephrine.[21] Unlike any other SGAs, ziprasidone was reported to block synaptic serotonin, norepinephrine and dopamine reuptake in vitro.[22,23] Evidence indicates that both 5-HT6 agonists and antagonists may evoke identical responses in animal models of MDD, although the possible mechanisms of these effects seem to be diverse and are not clearly understood. The augmented effects were notable by combining antidepressants with a selective 5-HT6 receptor antagonist.[24] There is also a considerable amount of evidence supporting a role for the 5-HT7 receptor in MDD. The blockade of the 5-HT7 receptor led to antidepressant-like effects in animal models of MDD. It should be also worthy to mention that augmentation of 5-HT7 receptor antagonists with antidepressants was remarkable in animal models of MDD.[25]

Another mechanism involving in the action of SGAs should be the alteration of the glutamate receptor activity, and thus restoring normal glutamatergic neurotransmission and reducing the chances of excitotoxicity.[26] Some SGA treatment may also cause a decrease in plasma adrenocorticotropic hormone concentration and a normalization of HPA-axis dynamics.[27] An impaired neuroprotection has also been implicated in the pathophysiology of MDD.[28,29] Interestingly, activation of the 5-HT1A receptors was shown to be neuroprotective against various brain insults such as N-methyl-daspartic acid.[30] Some SGAs have also demonstrated such neuroprotective effects indicating a potential role in the protection against excitotoxicity in vivo.[30]

Overall 5-HT2A antagonism should be a commonly shared biological relevance for most of the SGAs as a potential mechanism of their antidepressant effect. Interactive effects with the dopaminergic system may be more distinct with the action mechanism of amisulpride and aripiprazole, while norepinephrine- and/or serotonin-reuptake inhibition should be the unique case with quetiapine or ziprasidone.[31] Each antipsychotic has a distinct profile of affinities towards different neurotransmitter receptors, which should be associated mainly with mediation of antidepressant-like effects.

Second-generation Antipsychotics in the Treatment of Major Depressive Disorder

Упражнения, депрессии, цитокины

Exercise is an efficacious treatment for major depressive disorder (MDD) and has independently been shown to have anti-inflammatory effects in non-depressed subjects. Patients with MDD have elevated inflammatory cytokines but it is not known if exercise affects inflammation in MDD patients and whether these changes are clinically relevant. In the TReatment with Exercise Augmentation for Depression (TREAD) study, participants who were partial responders to a selective serotonin reuptake inhibitor were randomized to receive one of two doses of exercise: 16 kilocalories per kilogram of body weight per week (KKW), or 4 KKW for 12 weeks. Blood samples were collected before initiation and again at the end of the 12-week exercise intervention. Serum was analyzed using a multiplexed ELISA for interferon-γ (IFN-γ), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Higher baseline levels of TNF-α were associated with greater decrease in depression symptoms over the 12-week exercise period (P < 0.0001). In addition, a significant positive correlation between change in IL-1β and change in depression symptom scores was observed (P = 0.04). There were no significant changes in mean level of any cytokine following the 12-week intervention, and no significant relationship between exercise dose and change in mean cytokine level. Results suggest that high TNF-α may differentially predict better outcomes with exercise treatment as opposed to antidepressant medications for which high TNF-α is linked to poor response. Our results also confirm findings from studies of antidepressant medications that tie decreasing IL-1β to positive depression treatment outcomes.

 Pro-inflammatory cytokines as predictors of antidepressant effects of exercise in major depressive disorder

Schizophrenia, “Just the Facts” 5. Treatment and prevention Past, present, and future

ЭСТ в сравнении с антидепрессивным эффектом анестезии изофлюраном

Deep-inhalation isoflurane anesthesia has an antidepressant effect that approaches the effect of electroconvulsive therapy (ECT), with fewer cognitive side effects, preliminary results indicate.

Anesthetic a Better Alternative to ECT in Resistant Depression?