Potential use of psilocybin drugs in the treatment of depression.

INTRODUCTION: Depression is a common disabling psychiatric disorder, which - in extreme cases - may lead to suicide if untreated or inadequately treated. Despite the availability of various treatments for depression, including pharmacotherapy, there is still a need to search for new agents with higher effectiveness and faster onset of action, especially for patients with treatment-resistant depression. AREAS COVERED: A substance that has attracted considerable attention for nearly a decade is psilocybin, a natural psychedelic found in psilocybin mushrooms. In this study, we evaluated the efficacy and safety of psilocybin in the treatment of depression, based on pivotal randomized clinical trials. Moreover, we used findings from observational studies regarding recreational use. We also looked at ongoing clinical trials and discussed the registration status and clinical potential of the drug. EXPERT OPINION: Clinical phase I-II trials published to date reported promising results for psilocybin in the treatment of patients with major depressive disorder and treatment-resistant depression, in a relatively short time after administration. However, before psilocybin is approved for use and administered to patients with depression, the results of large ongoing phase III clinical trials are needed to confirm its efficacy and safety and to change the way it is perceived by physicians and patients.

Design and Synthesis of New Quinazolin-4-one Derivatives with Negative mGlu7 Receptor Modulation Activity and Antipsychotic-Like Properties.

Following the glutamatergic theory of schizophrenia and based on our previous study regarding the antipsychotic-like activity of mGlu7 NAMs, we synthesized a new compound library containing 103 members, which were examined for NAM mGlu7 activity in the T-REx 293 cell line expressing a recombinant human mGlu7 receptor. Out of the twenty-two scaffolds examined, active compounds were found only within the quinazolinone chemotype. 2-(2-Chlorophenyl)-6-(2,3-dimethoxyphenyl)-3-methylquinazolin-4(3H)-one (A9-7, ALX-171, mGlu7 IC50 = 6.14 µM) was selective over other group III mGlu receptors (mGlu4 and mGlu8), exhibited satisfactory drug-like properties in preliminary DMPK profiling, and was further tested in animal models of antipsychotic-like activity, assessing the positive, negative, and cognitive symptoms. ALX-171 reversed DOI-induced head twitches and MK-801-induced disruptions of social interactions or cognition in the novel object recognition test and spatial delayed alternation test. On the other hand, the efficacy of the compound was not observed in the MK-801-induced hyperactivity test or prepulse inhibition. In summary, the observed antipsychotic activity profile of ALX-171 justifies the further development of the group of quinazolin-4-one derivatives in the search for a new drug candidate for schizophrenia treatment.

New 1,2,4-oxadiazole derivatives with positive mGlu4 receptor modulation activity and antipsychotic-like properties.

Considering the allosteric regulation of mGlu receptors for potential therapeutic applications, we developed a group of 1,2,4-oxadiazole derivatives that displayed mGlu4 receptor positive allosteric modulatory activity (EC50 = 282-656 nM). Selectivity screening revealed that they were devoid of activity at mGlu1, mGlu2 and mGlu5 receptors, but modulated mGlu7 and mGlu8 receptors, thus were classified as group III-preferring mGlu receptor agents. None of the compounds was active towards hERG channels or in the mini-AMES test. The most potent in vitro mGlu4 PAM derivative 52 (N-(3-chloro-4-(5-(2-chlorophenyl)-1,2,4-oxadiazol-3-yl)phenyl)picolinamide) was readily absorbed after i.p. administration (male Albino Swiss mice) and reached a maximum brain concentration of 949.76 ng/mL. Five modulators (34, 37, 52, 60 and 62) demonstrated significant anxiolytic- and antipsychotic-like properties in the SIH and DOI-induced head twitch test, respectively. Promising data were obtained, especially for N-(4-(5-(2-chlorophenyl)-1,2,4-oxadiazol-3-yl)-3-methylphenyl)picolinamide (62), whose effects in the DOI-induced head twitch test were comparable to those of clozapine and better than those reported for the selective mGlu4 PAM ADX88178.

Role of AMPA receptor stimulation and TrkB signaling in the antidepressant-like effect of ketamine co-administered with a group II mGlu receptor antagonist, LY341495, in the forced swim test in rats.

Ketamine has been shown to induce a rapid antidepressant effect on patients with depression. In many animal models, both rapid and sustained antidepressant activities were also found in response to an antagonist of group II metabotropic glutamate receptors, LY341495, and its mechanism of action seemed to be similar in many ways to the action of ketamine. It has also been found that LY341495 enhanced the antidepressant-like activity of sub-effective doses of ketamine in rats without inducing adverse effects. Here, we investigated the role of AMPA receptor and TrkB receptor activation in the antidepressant-like effects of ketamine (3 mg/kg) co-administered with LY341495 (0.1 mg/kg), in the forced swim test in rats, at three time points (40 min, 3 h and 24 h) after joint administration of the tested compounds. It was found that the AMPA receptor antagonist NBQX (10 mg/kg) reversed the antidepressant effect of ketamine co-administered with LY341495 at all tested time points, whereas the TrkB receptor antagonist ANA-12 contributed to blockade of the effect of ketamine and LY341495 3 h after their joint administration. These results indicate that activation of AMPA receptor and BDNF-related signaling may play a role in the mechanism of antidepressant action of ketamine co-administered with LY341495.

Cost-utility analysis of 1-year treatment with adalimumab/standard care and standard care alone for ulcerative colitis in Poland.

PURPOSE: Until recently, surgery was the only remaining choice for moderate to severe chronic ulcerative colitis patients who failed standard treatment or when it was not tolerated. Anti-TNFα treatment is a new, non-invasive option for the management of ulcerative colitis. The objective of this study was to assess the cost-effectiveness of induction and maintenance treatment up to 1 year of ulcerative colitis with adalimumab/standard care and standard care alone in Poland. METHODS: A Markov model was used to estimate the expected costs and effects of adalimumab/standard care and a standard care alone. For each treatment option, the costs and quality adjusted life years were calculated to estimate the incremental cost-utility ratio. The analysis was performed from the perspective of the Polish public payer and society over a 30-year time horizon. Different direct and indirect costs and utility values were assigned to the various model health states. RESULTS: The treatment of ulcerative colitis patients with adalimumab/standard care up to 1 year instead of a standard care alone resulted in 0.14 additional years of life with full health (QALYs). The incremental cost-utility ratio of adalimumab/standard care compared to the standard care alone is estimated to be 76,120 €/QALY gained from NHF perspective and 71,457 €/QALY gained from social perspective. CONCLUSIONS: The biologic treatment of ulcerative colitis patients with adalimumab/standard care is more effective but also more costly compared with standard care alone.

Expression of group III metabotropic glutamate receptors in the reproductive system of male mice.

Although the presence of metabotropic glutamate (mGlu) receptors in the central nervous system is well documented, they have recently been found in peripheral and non-neuronal tissues. In the present study we investigated the expression of group III mGlu receptors in the reproductive system of male mice. Reverse transcription-polymerase chain reaction analysis revealed the presence of mGlu6, mGlu7 and mGlu8 (but not mGlu4) receptor transcripts in testes and epididymides from adult mice. In addition, expression of mGlu6 (Grm6) and mGlu8 receptor (Grm8) mRNA was detected in spermatozoa isolated from the vas deferens. The vas deferens was found to contain only mGlu7 receptor (Grm7) mRNA, which was particularly intense in 21-day-old male mice. In penile homogenates, only the mGlu7 receptor signal was detected. Genetic ablation of the mGlu7 receptor in males led to fertility disorders manifested by decreased insemination capability as well as deterioration of sperm parameters, particularly sperm motility, vitality, sperm membrane integrity and morphology, with a simultaneous increase in sperm concentration. These results indicate that constitutively expressed mGlu receptors in the male reproductive system may play an important role in ejaculation and/or erection processes, as well as in the formation and maturation of spermatozoa.

Disease activity, quality of life and indirect costs of psoriatic arthritis in Poland.

The aim of the study was to assess the indirect costs, health-related quality of life and clinical characteristics of patients with psoriatic arthritis (PsA), measured using a PsA disease activity index in Poland. Additionally, we aimed to investigate the association between the activity, utility of PsA-affected patients and productivity loss in a Polish setting. A questionnaire survey was conducted to assess disease activity, as well as productivity loss, and a paper version of the EuroQoly-5D-3L questionnaire was used to assess productivity loss and the quality of life. Indirect costs were assessed with the human capital approach employing the gross domestic product (GDP) per capita, gross value added (GVA) and gross income (GI) per worker in 2014 in Poland and were expressed in Polish zlotys (PLN) as well as in euros. The correlation was presented using the Spearman correlation coefficient. Our analysis was performed on the basis of 50 full questionnaires collected. We observed a mean utility value of 0.6567. The mean number of days off work was 2.88 days per month, and mean on-the-job productivity loss was 24.1 %. Average monthly indirect costs per patient were €206.7 (864.01 PLN) calculated using the GDP; €484.56 (2025.46 PLN) calculated using the GVA; and €209.70 (876.56 PLN) calculated using the GI. PsA reduces the patients' quality of life as well as their productivity loss associated with both absenteeism and presenteeism. Total indirect costs were negatively correlated with utility. The greater the disease activity, the lower the utility and the greater the indirect costs.

Functional Selectivity and Antidepressant Activity of Serotonin 1A Receptor Ligands.

Serotonin (5-HT) is a monoamine neurotransmitter that plays an important role in physiological functions. 5-HT has been implicated in sleep, feeding, sexual behavior, temperature regulation, pain, and cognition as well as in pathological states including disorders connected to mood, anxiety, psychosis and pain. 5-HT1A receptors have for a long time been considered as an interesting target for the action of antidepressant drugs. It was postulated that postsynaptic 5-HT1A agonists could form a new class of antidepressant drugs, and mixed 5-HT1A receptor ligands/serotonin transporter (SERT) inhibitors seem to possess an interesting pharmacological profile. It should, however, be noted that 5-HT1A receptors can activate several different biochemical pathways and signal through both G protein-dependent and G protein-independent pathways. The variables that affect the multiplicity of 5-HT1A receptor signaling pathways would thus result from the summation of effects specific to the host cell milieu. Moreover, receptor trafficking appears different at pre- and postsynaptic sites. It should also be noted that the 5-HT1A receptor cooperates with other signal transduction systems (like the 5-HT1B or 5-HT2A/2B/2C receptors, the GABAergic and the glutaminergic systems), which also contribute to its antidepressant and/or anxiolytic activity. Thus identifying brain specific molecular targets for 5-HT1A receptor ligands may result in a better targeting, raising a hope for more effective medicines for various pathologies.

The effectiveness of dimethyl fumarate monotherapy in the treatment of relapsing-remitting multiple sclerosis: a systematic review and meta-analysis.

BACKGROUND: Dimethyl fumarate (BG-12, Tecfidera®) is a new oral drug approved by FDA and EMA in March 2013 for relapsing - remitting multiple sclerosis (RRMS). The drug was much anticipated because of its possible superiority over currently available medications: fingolimod and teriflunomide as the only MS treatments currently available in oral form. OBJECTIVE: The aim of this systematic review with meta-analysis was to assess the efficacy and safety of BG-12 in the treatment of RRMS. METHODS: A systematic literature search was conducted in Medline/PubMed, EMBASE, and Cochrane Library up till 3(rd) November, 2013. We sought all published randomized clinical trials evaluating the use of dimethyl fumarate for the treatment of patients with RRMS. All included studies were critically appraised and analyzed with the use of Review Manager 5.1.0. software according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement protocol. RESULTS: Two trials, DEFINE and CONFIRM involved 2 651 patients and compared dimethyl fumarate taken either two or three times daily with placebo in patients with RRMS. Additionally in CONFIRM trial third group of patients received glatiramer acetate. The overall results of the meta-analysis showed that BG-12 (at both dosages) given to patients with RRMS is safe and statistically significantly more effective than placebo in reducing the proportion of patients who had a relapse by 2 years, the rate of disability progression and the mean number of gadolinium-enhancing lesions at 2 years. The comparison between BG-12 and glatiramer acetate revealed that the analyzed agent could potentially be more effective in the treatment of RRMS. CONCLUSIONS: Despite limited RCTs data available, both analyzed BG-12 regimens showed their efficacy on clinical disease parameters and other measures of disease activity in RRMS. The safety profile of the study agent was acceptable.

[The role of the cytostatic drugs unit in rationalization of hospital drugs management--the case study and the analysis of drug utilization]. / Znaczenie pracowni leków cytostatycznych w racjonalizacji szpitalnej gospodarki lekami--studium przypadku i analiza uzytkowania leków.

UNLABELLED: Until recently, the cytostatic drugs were being prepared at the Polish hospitals by the nursing staff on hospital wards, however according to the Pharmaceutical Law, preparation of cytostatic drugs, as a pharmaceutical service, should be performed by the pharmacists, who possess appropriate qualifications and experience in working within aseptic conditions and who are trained in professional handling with harmful substances. The aim of this paper has been to assess the impact, which establishment of the cytostatic drugs unit at the hospital pharmacy of the big oncologic hospital, located in southern Poland, had on the overall costs of cytostatic drugs utilization. MATERIAL AND METHODS: The analysis of drugs consumption, as well as determining the size of losses of particular active substances, prepared by the cytostatic drugs unit, have been based on statistical reports, provided by the hospital pharmacy. In order to calculate the level of consumption and losses of active substances in the chemotherapy ward, in framework of the previous modality of function, the estimations have been done, taking into consideration the same needs of particular patients, as those included within reports provided by the pharmacy. The actual prices of drugs from year 2012 have been applied in the assessment of costs of drug utilization. The calculations have been done with Excel and SPSS v.21 software. The methods of descriptive statistics and the comparison of groups, using the Student's t-test for dependent samples have been applied. RESULTS: Due to functioning of the centralized modality of cytostatic drugs preparation within the specialized unit, the decline of overall cytostatic drug consumption, amounting to 9.73% has been observed. The reduction in losses, on stage of preparation of drugs, has been achieved and the share of these losses within overall consumption of drugs has dropped by 77.28%. The dissolution of cytostatic drugs in the cytostatic drugs unit, instead of the chemotherapy ward, allows the hospital to achieve the yearly savings, exceeding PLN 572,276.07. CONCLUSIONS: Establisment of the cytostatic drugs unit, at the hospital pharmacy of the specialist oncologic hospital, not only allowed for increasing quality of pharmacotherapy, but also for substantial savings, when compared with the previously used method of dissolving and preparing cytostatic drugs by the nurses, instantly at the chemotherapy wards.

[Clinical efficacy and safety of prolonged use of the valganciclovir for the treatment of cytomegalovirus disease in patients after kidney transplantation]. / Skutecznosc kliniczna oraz bezpieczenstwo przedluzonego stosowania walgancyklowiru w leczeniu choroby cytomegalowirusowej u chorych po przeszczepie nerki.

UNLABELLED: Cytomegalovirus infection is particularly dangerous for patients undergoing solid organs transplantation. Among these patients cytomegalovirus disease (CMV) may occur. CMV disease is associated with increased mortality, organ damage and reduced graft survival. THE AIM OF THE STUDY was to determine the clinical outcomes (clinical efficacy and safety profile) for the use of valganciclovir administered for 200 days compared to standard period of 100 days in the prevention of cytomegalovirus disease in seronegative patients after kidney transplantation from infected donor (high risk patients). MATERIAL AND METHODS: A systematic review of literature published during the period: 1st January 1966-31st October 2010, was performed in order to assess the efficacy and safety of valganciclovir in the treatment of cytomegalovirus disease. Databases MEDLINE (PubMed), EMBASE and Cochrane were searched. RESULTS: A systematic review yielded 1 randomized and 3 nonrandomized clinical trials. 200 days prophylaxis with valganciclovir significantly decreased a risk of: cytomegalovirus disease, CMV viral load, opportunistic infections; percentage of patients with high viral load was also significantly decreased compared to 100 days therapy. The safety profile of extended therapy was similar to that observed within 100 days prophylaxis. The higher risk of leucopenia in the 200 days than 100 days group was the only one adverse event that met statistical significance. The results of non-randomized trials were comparable to those mentioned above. CONCLUSION: Prolonged prophylaxis of cytomegalovirus till 200 days in high-risk patients (D+/B-) is safe and provides significant therapeutic benefits.

Interaction of hallucinogenic rapid-acting antidepressants with mGlu2/3 receptor ligands as a window for more effective therapies.

The desire to find a gold-standard therapy for depression is still ongoing. Developing one universal and effective pharmacotherapy remains troublesome due to the high complexity and variety of symptoms. Over the last decades, the understanding of the mechanism of pathophysiology of depression and its key consequences for brain functioning have undergone significant changes, referring to the monoaminergic theory of the disease. After the breakthrough discovery of ketamine, research began to focus on the modulation of glutamatergic transmission as a new pharmacological target. Glutamate is a crucial player in mechanisms of a novel class of antidepressants, including hallucinogens such as ketamine. The role of glutamatergic transmission is also suggested in the antidepressant (AD) action of scopolamine and psilocybin. Despite fast, robust, and sustained AD action hallucinogens belonging to a group of rapid-acting antidepressants (RAA) exert significant undesired effects, which hamper their use in the clinic. Thus, the synergistic action of more than one substance in lower doses instead of monotherapy may alleviate the likelihood of adverse effects while improving therapeutic outcomes. In this review, we explore AD-like behavioral, synaptic, and molecular action of RAAs such as ketamine, scopolamine, and psilocybin, in combination with mGlu2/3 receptor antagonists.

The Potential of Scopolamine as an Antidepressant in Major Depressive Disorder: A Systematic Review of Randomized Controlled Trials.

Major depressive disorder is one of the most severe mental disorders. It strongly impairs daily functioning, and, in extreme cases, it can lead to suicide. Although different treatment options are available for patients with depression, there is an ongoing search for novel therapeutic agents, such as scopolamine (also known as hyoscine), that would offer higher efficacy, a more rapid onset of action, and a more favorable safety profile. The aim of our study was to review the current clinical evidence regarding the use of scopolamine, a promising therapeutic option in the treatment of depression. A systematic literature search was performed using PubMed, Embase, and CENTRAL databases up to 5 June 2023. We included randomized placebo-controlled or head-to-head clinical trials that compared the clinical efficacy and safety of scopolamine in the treatment of major depressive disorder. Two reviewers independently conducted the search and study selection and rated the risk of bias for each study. Four randomized controlled trials were identified in the systematic review. The included studies investigated the use of scopolamine administered as an oral, intramuscular, or intravenous drug, alone or in combination with other antidepressants. The results indicated that scopolamine exerts antidepressant effects of varying intensity. We show that not all studies confirmed a statistically and clinically significant reduction of depressive symptoms vs. placebo. A broader perspective on scopolamine use in antidepressant treatment should be confirmed in subsequent large randomized controlled trials assessing both effectiveness and safety. Therefore, studies directly comparing the effectiveness of scopolamine depending on the route of administration are required.

Simultaneous alterations of brain and plasma serotonin concentrations and liver cytochrome P450 in rats fed on a tryptophan-free diet.

Our previous study suggested involvement of the brain serotonergic system in the regulation of liver cytochrome P450 (CYP). The aim of the present study was to demonstrate simultaneous responsiveness of liver CYP and the peripheral and brain serotonergic systems to a tryptophan deficient diet during three days and one or three weeks of ingestion. The concentrations of serotonin, noradrenaline, dopamine and their metabolites were measured in blood plasma, the hypothalamus and brain stem of male rats. The enzyme activity and protein levels in the liver were determined for isoforms CYP1A, CYP2A, CYP2B, CYP2C6, CYP2C11, CYP2D and CYP3A. A three-day tryptophan-free diet increased serotonin content in the hypothalamus (but not in the brain stem or plasma). After one week, the level of serotonin was not changed in the brain, but was markedly increased in the plasma. A three week tryptophan restriction significantly reduced the concentration of serotonin in the brain and plasma. Changes in CYP2C6 and CYP2C11 (an increase and a decrease, respectively) were maintained throughout the experiment, while those found in other CYP isoforms varied, which usually resulted in a gradual increase in the enzyme activity within three weeks. The observed alterations in liver CYPs suggest involvement of both central and peripheral serotonin in the regulation of liver CYP expression whose mechanism is discussed. In conclusion, a deficit in tryptophan in the diet may be responsible for very serious food-cytochrome P450 and food-drug metabolism interactions. Interactions of this type may also refer to drugs acting via serotonergic system.

Where do we go next in antidepressant drug discovery? A new generation of antidepressants: a pivotal role of AMPA receptor potentiation and mGlu2/3 receptor antagonism.

INTRODUCTION: Major depressive disorder remains a prevalent world-wide health problem. Currently available antidepressant medications take weeks of dosing, do not produce antidepressant response in all patients, and have undesirable ancillary effects. AREAS COVERED: The present opinion piece focuses on the major inroads to the creation of new antidepressants. These include N-methyl-D-aspartate (NMDA) receptor antagonists and related compounds like ketamine, psychedelic drugs like psilocybin, and muscarinic receptor antagonists like scopolamine. The preclinical and clinical pharmacological profile of these new-age antidepressant drugs is discussed. EXPERT OPINION: Preclinical and clinical data have accumulated to predict a next generation of antidepressant medicines. In contrast to the current standard of care antidepressant drugs, these compounds differ in that they demonstrate rapid activity, often after a single dose, and effects that outlive their presence in brain. These compounds also can provide efficacy for treatment-resistant depressed patients. The mechanism of action of these compounds suggests a strong glutamatergic component that involves the facilitation of AMPA receptor function. Antagonism of mGlu2/3 receptors is also relevant to the antidepressant pharmacology of this new class of drugs. Based upon the ongoing efforts to develop these new-age antidepressants, new drug approvals are predicted in the near future.

Chronic treatment with zinc and antidepressants induces enhancement of presynaptic/extracellular zinc concentration in the rat prefrontal cortex.

Zinc exhibits antidepressant-like activity in preclinical tests/models. Moreover, zinc homeostasis is implicated in the pathophysiology of affective disorders. The aim of the present study was to examine the effect of chronic zinc, citalopram and imipramine intraperitoneal administration on the presynaptic and extracellular zinc concentration in the rat prefrontal cortex and hippocampus. We used two methods: zinc-selenium histochemistry (which images the pool of presynaptic-vesicle zinc) and anodic stripping voltammetry (ASV) for zinc determination in microdialysate (which assays the extracellular zinc concentration). We report that chronic (14 ×) zinc (hydroaspartate, 10 and 65 mg/kg) and citalopram (20 mg/kg) administration increased the pool of presynaptic zinc (by 34, 50 and 37%, respectively) in the rat prefrontal cortex. The 21% increase induced by imipramine (20 mg/kg) was marginally significant. Likewise, zinc (hydroaspartate, 65 mg/kg), citalopram and imipramine increased the extracellular zinc (although with a different pattern: time point, area under the curve and/or basal level) in this brain region. Furthermore, zinc induced an increase in presynaptic (by 65%) and extracellular zinc (by 90%) in the hippocampus, while both citalopram and imipramine did not. These results indicate that all of the treatments increase presynaptic/extracellular zinc concentrations in the rat prefrontal cortex, which may then contribute to their antidepressant mechanisms. Alterations induced by zinc (but not antidepressants) administration in the hippocampus may be related to specific zinc mechanisms. All the data (previous and present) on the effect of antidepressant treatments on the presynaptic/extracellular zinc concentrations suggest the involvement of this biometal presynaptic/synaptic homeostasis in the antidepressant mechanism(s).

Pharmaco-Electroencephalography-Based Assessment of Antidepressant Drug Efficacy-The Use of Magnesium Ions in the Treatment of Depression.

Pharmaco-electroencephalography (pharmaco-EEG) is a technique used to assess the effects of psychotropic medications on the bioelectrical activity of the brain. The purpose of this study was to assess the treatment response with the use of the Hamilton Depression Rating Scale (HDRS) and via EEG. Over an 8-week period, we analyzed electroencephalographic tracings of 91 patients hospitalized for major depression at the Medical University of Warsaw. Thirty-nine of those patients received tricyclic antidepressants (TCAs), 35 received fluoxetine, and 17 received fluoxetine augmented with magnesium (Mg) ions. All patients had their serum drug levels monitored. The highest proportion of patients (88.2%) who showed adequate responses to treatment was observed in the fluoxetine+Mg group, whereas the lowest rates of treatment response were observed in the TCA group (58.3%). This difference was statistically significant (p = 0.029, Phi = 0.30). Our study demonstrated a relationship between achieving remission (HDRS ≤ 6 at week 8 of treatment) and obtaining a positive pharmaco-EEG profile 6 h after administration of the first dose in the group receiving fluoxetine augmented with Mg ions (p = 0.035, Phi = 0.63).

The antidepressant-like action of metabotropic glutamate 7 receptor agonist N,N'-bis(diphenylmethyl)-1,2-ethanediamine (AMN082) is serotonin-dependent.

Behavioral studies show that modulation of the glutamatergic system might be an efficient way to achieve antidepressant activity. Among the group III metabotropic glutamate (mGlu) receptors, the mGlu7 receptor subtype seems to be the most promising target for potential antidepressants. It has been shown that a selective, allosteric mGlu7 receptor agonist, N,N'-bis (diphenylmethyl)-1,2-ethanediamine (AMN082), induced antidepressant-like action in behavioral tests in mice, although the mechanisms responsible for this action remained unknown. Here, we decided to investigate the possible role of the serotonergic system in the antidepressant-like activity of AMN082 in both the forced swim test (FST) in rats and the tail suspension test (TST) in mice. We found that AMN082 (1-10 mg/kg i.p.) induced a dose-dependent reduction in the immobility of rats and an increase in their swimming behavior, whereas there were not any changes in climbing behavior in the FST in rats. In the TST in mice we found that AMN082 (3 mg/kg i.p.) did not induce an antidepressant-like effect after depletion of serotonin (5-HT) with para-chlorophenylalanine. Moreover, we revealed that citalopram, but not reboxetine, when combined with AMN082 (all compounds used at low subeffective doses), induced a significant antidepressant-like effect in the TST. We also discovered that the 5-HT1A receptor antagonist N-{2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridynyl) cyclohexane-carboxamide (WAY100635) (0.1 mg/kg s.c.), but not the 5-HT2A/2C receptor antagonist ritanserin (0.5 mg/kg i.p.), blocked the antidepressant-like action of AMN082. Altogether, the results of our studies show that the antidepressant-like action of the mGlu7 receptor-positive modulator AMN082 depends on the activation of the serotonergic system.

Developments in the discovery and design of intranasal antidepressants.

INTRODUCTION: Depression remains a major cause of morbidity worldwide; consequently, there is a need in neuropsychiatry for new antidepressants with a rapid onset of action. Intranasal administration of antidepressants is an attractive and promising approach to the treatment of mental disorders, as this route is noninvasive, offers a fast onset of action and improved drug bioavailability, allows a drug dose reduction, as well as gives the possibility to bypass the blood-brain barrier and reduce the number of systemic side effects. AREAS COVERED: This review is a comprehensive discussion of the available intranasal drugs that have found application as antidepressants. The results of relevant clinical studies are presented. Additionally, the use of nanotechnology-based formulations for enhancing the intranasal delivery of antidepressants is briefly described. EXPERT OPINION: Intranasal drug delivery has a huge potential for antidepressant administration, but its use in the treatment of central nervous system disorders is currently very limited. The nasal route of antidepressant delivery is noninvasive, improves drug bioavailability, as well as allows to overcome the problem with the blood-brain barrier, gastrointestinal absorption, and first-pass metabolism. In our opinion, fast-acting intranasal antidepressants will be widely used in the treatment of mental disorders in the future.

Efficacy and safety of intranasal esketamine for the treatment of major depressive disorder.

Introduction: In March 2019, intranasal esketamine was approved by the Food and Drug Administration (FDA) for the treatment of treatment-resistant depression (TRD) in adults. This review presents the results of clinical trials underlying the FDA approval of intranasal esketamine.Areas covered: Esketamine's efficacy and safety in TRD were assessed in 5 phase III studies: three 4-week, placebo-controlled studies, and two long-term trials. One short-term trial showed statistically significant antidepressant effects of esketamine vs placebo, while a long-term withdrawal study showed that esketamine is significantly beneficial in terms of extending time to relapse, compared to placebo. Two other short-term trials did not meet the prespecified statistical tests for showing efficacy, although improvement in depressive symptoms from baseline to the end of week 4 favors esketamine over placebo.Expert opinion: Intranasal esketamine is a new treatment option for people with TRD. The main benefit of esketamine is rapid onset of antidepressant activity, but the effects of prolonged treatment are still preliminary. The main concerns relate to the safety aspects of prolonged esketamine therapy, when considering its abuse potential. While data for esketamine use over a long period of time is lacking, its use should be carefully monitored.