Vilazodone for the treatment of major depressive disorder: focusing on its clinical studies and mechanism of action

Design, synthesis, and biological evaluation of aralkyl piperazine and piperidine derivatives targeting SSRI/5-HT1A/5-HT7

Serotonin reuptake inhibition combined with the action targeting 5-hydroxytryptamine receptor subtypes can serve as a potential target for the development of antidepressant drugs. Herein a series of new aralkyl piperazines and piperidines were designed and synthesized by the structural modifications of the previously discovered aralkyl piperidine compound 1, targeting SSRI/5-HT1A/5-HT7. The results exhibited that compound 5a showed strong binding to 5-HT1A and 5-HT7 (Ki of 0.46 nM, 2.7 nM, respectively) and a high level of serotonin reuptake inhibition (IC50 of 1.9 nM), all of which were significantly elevated compared to 1. In particular, compound 5a showed weaker inhibitory activity against hERG than 1, and demonstrated good stability in liver microsomes in vitro. The preliminary screening using FST indicated that orally administered 5a, at a high dose, could reduce immobility time in mice markedly, indicating potential antidepressant activity.

Vilazodone Alleviates Neurogenesis-Induced Anxiety in the Chronic Unpredictable Mild Stress Female Rat Model: Role of Wnt/β-Catenin Signaling

Defective β-catenin signaling is accompanied with compensatory neurogenesis process that may pave to anxiety. β-Catenin has a distinct role in alleviating anxiety in adolescence; however, it undergoes degradation by the degradation complex Axin and APC. Vilazodone (VZ) is a fast, effective antidepressant with SSRI activity and 5-HT1A partial agonism that amends somatic and/or psychic symptoms of anxiety. Yet, there is no data about anxiolytic effect of VZ on anxiety-related neurogenesis provoked by stress-reduced β-catenin signaling. Furthermore, females have specific susceptibility toward psychopathology. The aim of the present study is to uncover the molecular mechanism of VZ relative to Wnt/β-catenin signaling in female rats. Stress-induced anxiety was conducted by subjecting the rats to different stressful stimuli for 21 days. On the 15th day, stressed rats were treated with VZ(10 mg/kg, p.o.) alone or concomitant with the Wnt inhibitor: XAV939 (0.1 mg/kg, i.p.). Anxious rats showed low β-catenin level turned over by Axin-1 with unanticipated reduction of APC pursued with elevated protein levels of neurogenesis-stimulating proteins: c-Myc and pThr183-Erk likewise gene expressions of miR-17-5p and miR-18. Two weeks of VZ treatment showed anxiolytic effect figured by alleviation of hippocampal histological examination. VZ protected β-catenin signal via reduction in Axin-1 and elevation of APC conjugated with modulation of β-catenin downstream targets. The cytoplasmic β-catenin turnover by Axin-1 was restored by XAV939. Herein, VZ showed anti-anxiety effect, which may be in part through regaining the balance of the reduced β-catenin and its subsequent exaggerated response of p-Erk, c-Myc, Dicer-1, miR-17-5p, and miR-18.

Activating SRC/MAPK signaling via 5-HT1A receptor contributes to the effect of vilazodone on improving thrombocytopenia

Thrombocytopenia caused by long-term radiotherapy and chemotherapy exists in cancer treatment. Previous research demonstrates that 5-Hydroxtrayptamine (5-HT) and its receptors induce the formation of megakaryocytes (MKs) and platelets. However, the relationships between 5-HT1A receptor (5-HTR1A) and MKs is unclear so far. We screened and investigated the mechanism of vilazodone as a 5-HTR1A partial agonist in promoting MK differentiation and evaluated its therapeutic effect in thrombocytopenia. We employed a drug screening model based on machine learning (ML) to screen the megakaryocytopoiesis activity of Vilazodone (VLZ). The effects of VLZ on megakaryocytopoiesis were verified in HEL and Meg-01 cells. Tg (itga2b: eGFP) zebrafish was performed to analyze the alterations in thrombopoiesis. Moreover, we established a thrombocytopenia mice model to investigate how VLZ administration accelerates platelet recovery and function. We carried out network pharmacology, Western blot, and immunofluorescence to demonstrate the potential targets and pathway of VLZ. VLZ has been predicted to have a potential biological action. Meanwhile, VLZ administration promotes MK differentiation and thrombopoiesis in cells and zebrafish models. Progressive experiments showed that VLZ has a potential therapeutic effect on radiation-induced thrombocytopenia in vivo. The network pharmacology and associated mechanism study indicated that SRC and MAPK signaling are both involved in the processes of megakaryopoiesis facilitated by VLZ. Furthermore, the expression of 5-HTR1A during megakaryocyte differentiation is closely related to the activation of SRC and MAPK. Our findings demonstrated that the expression of 5-HTR1A on MK, VLZ could bind to the 5-HTR1A receptor and further regulate the SRC/MAPK signaling pathway to facilitate megakaryocyte differentiation and platelet production, which provides new insights into the alternative therapeutic options for thrombocytopenia.

Vilazodone-phospholipid mixed micelles for enhancing oral bioavailability and reducing pharmacokinetic variability between fed and fasted states

Despite the effectiveness and high tolerability of vilazodone (VLZ) as an antidepressant, its use is still limited due to its poor solubility and food dependent absorption. This study aims to load VLZ-phospholipid complex into self-assembled micelles forming VLZ-PL mixed micelles (VLZ-PL-MM), that can enhance VLZ solubility, improve its bioavailability and reduce the pharmacokinetic variability between the fed and fasting conditions. The effect of the surfactant type and concentration was assessed using four different non-ionic surfactants (Brij 58, Tween 80, Labrasol and Pluronic F127) in four different weight ratios between the drug-complex and surfactant (1:0.5, 1:1, 1:2 and 1:3 w/w). Two VLZ-PL-MM formulae prepared using Brij 58 and Labrasol in 1:3 w/w ratio were selected as optimised ones since they have the highest encapsulation efficiency (100.83 and 93.87%, respectively), a particle size below 250 nm (206.73 and 221.33 nm, respectively) and negative zeta potential values (-29.63, -17.20 mV, respectively). Lyophilisation of these formulations using 3% sucrose was successful with no statistical changes in particle size and zeta potential upon rehydration. Both formulations elicited faster and higher in-vitro drug release profiles compared to the pure drug and the marketed tablet. In addition, both selected formulae improved ex-vivo permeation across rabbit intestinal membrane compared to the pure drug and the marketed tablet, with marked superiority of the one prepared using Brij 58. The results of the in vivo study in male albino rabbits revealed similar AUC_0-24 values after the oral administration of the best achieved VLZ-PL-MM system under fed and fasting conditions (769.89 and 741.55 ng.h mL^-1, respectively). On the other hand, the marketed product showed significantly lower values of the AUC_0-24 relative to the VLZ-PL-MM system and there was a marked enhancement of absorption of drug from the marketed product in presence of food (244.24 and 174.96 ng.h mL^-1 under fed and fasting conditions, respectively. In addition, VLZ concentrations in the brain after 24 hours obtained from the selected VLZ-PL-MM were significantly higher than those obtained from marketed tablet under fed and fasting conditions. Thus, the phospholipid mixed micelle formulation enhances the oral bioavailability of the poorly soluble drug and reduces the pharmacokinetic variability between fasting and fed conditions.

Involvement of kynurenine pathway and N-methyl-d-aspartate receptors in the antidepressant-like effect of vilazodone in the tail suspension test in mice

The present study evaluated the antidepressant-like effects of vilazodone using the tail suspension test in mice. We also investigated the contribution of kynurenine pathway and N-methyl-d-aspartate receptors to this effect. For this purpose, we pretreated animals with sub-effective doses of L-kynurenine, 3-hydroxykynurenine, or quinolinic acid. We then assessed the immobility time, an indicative measure of depressive-like behavior, in the tail suspension test. We also evaluated the possible effects of sub-effective doses of vilazodone combined with sub-effective doses of ketamine (N-methyl-d-aspartate receptor antagonist) in a separate group. Vilazodone (3mg/kg, intraperitoneal) significantly reduced immobility time in the tail suspension test. L-kynurenine (1.7 mg/kg, intraperitoneal), 3-hydroxykynurenine (10 mg/kg, intraperitoneal), and quinolinic acid (3 nmol/site, intracerebroventricular) significantly increased the immobility time in the tail suspension test. The antidepressant-like effects of vilazodone (3mg/kg, intraperitoneal) were inhibited by pre-treatment with non-effective doses of L-kynurenine (0.83 mg/kg, intraperitoneal), 3-hydroxykynurenine (3.33 mg/kg, intraperitoneal), or quinolinic acid (1 nmol/site, intracerebroventricular). Pretreatment of mice with sub-effective doses of ketamine (1 mg/kg, intraperitoneal) optimized the action of a sub-effective dose of vilazodone (0.3mg/kg, intraperitoneal) and reduced the immobility time in the tail suspension test. None of the drugs used in this study induced any changes in locomotor activity in the open field test. The results showed that vilazodone induced an antidepressant-like effect in the tail suspension test, which may be mediated through an interaction with the kynurenine pathway and N-methyl-d-aspartate receptors.

Nitrile-containing pharmaceuticals: target, mechanism of action, and their SAR studies

The nitrile group is an important functional group widely found in both pharmaceutical agents and natural products. More than 30 nitrile-containing pharmaceuticals have been approved by the FDA for the management of a broad range of clinical conditions in the last few decades. Incorporation of a nitrile group into lead compounds has gradually become a promising strategy in rational drug design as it can bring additional benefits including enhanced binding affinity to the target, improved pharmacokinetic profile of parent drugs, and reduced drug resistance. This paper reviews the existing drugs with a nitrile moiety that have been approved or in clinical trials, involving their targets, molecular mechanism of pharmacology and SAR studies, and classifies them into different categories based on their clinical usages.

In silico decryption of serotonin-receptor binding: local non-covalent interactions and long-range conformational changes

Serotonin-receptor binding is the key step in the process behind serotonin functionality, including several psychological and physiological behaviours. This study is focused on identifying the main non-covalent interactions controlling the stability of serotonin-receptor complexes as well as the main conformational changes in the receptor due to serotonin-receptor binding using classical molecular dynamics simulations and quantum chemical calculations. A qualitative analysis based on two order parameters ((i) the centre of mass distance and (ii) the angle between the surface normals of each aromatic residue and serotonin in the binding site) on the serotonin-receptor complex trajectory suggests that the T-type stacking interaction is predominant in the binding site. Quantum chemical calculations of the stacking interaction energy provide the quantitative contributions of important aromatic residues to the stabilization of the complex. Furthermore, a three body stacking interaction (named 'L'-type) was observed and likely contributes to the stability of the complex. Direct and water-mediated hydrogen bonding between the residues in the binding site and serotonin contributes to the complex stability. Principal component analysis of the molecular dynamics simulation trajectory of the serotonin-receptor complex and the apo-receptor in water indicates that the whole receptor is significantly stabilized due to serotonin binding. An analysis based on the dynamic cross correlation function reflects the strong correlation between trans-membrane (TM)3, TM5, TM6 (containing residues responsible for the stacking interaction and hydrogen bonding) and mini-G0 which may participate in signal transduction leading to the functionality of serotonin.

Comparative evaluation of efficacy and tolerability of vilazodone, escitalopram, and amitriptyline in patients of major depressive disorder: A randomized, parallel, open-label clinical study

OBJECTIVES

To evaluate and compare efficacy and tolerability of Vilazodone with Escitalopram and Amitriptyline in patients of major depressive disorder(MDD).

METHODS

This was a randomized, prospective, parallel-group, open label clinical study in which newly diagnosed patients of MDD were randomized to receive Tab Vilazodone 20 mg daily or Tab Escitalopram 20mg daily or Tab Amitriptyline 75mg daily for 12 weeks. Antidepressant activity was assessed by change in score from baseline to week 12 on HAMD-17 and MADRS scales while change in score on HAM-A scale was used to assess antianxiety effect. Change in scores on the three scales was also compared between the three treatment groups. Severity and causality of adverse events were assessed by the modified Hartwig & Siegel scale and Naranjo scale respectively. Data was analyzed in accordance with per protocol analysis.

RESULTS

Reduction in HAMD-17 and MADRS scores was significantly more in vilazodone group compared to the other two drugs indicating that vilazodone is more efficacious antidepressant. Number of remitters were also significantly more in the vilazodone group (n=11) compared to escitalopram (n=4) (p<0.05) and amitriptyline (n=0) (p<0.001) at 12 weeks. Similar results were also obtained with HAM-A score. Number of patients showing MADRS sustained response at 12 weeks was statistically significantly more in vilazodone (n=12) and escitalopram (n=12) groups compared to amitriptyline (n=01) (p<0.001). Reported adverse events were constipation and sedation(amitriptyline group); nausea and headache(escitalopram and vilazodone groups). These adverse events were of mild severity. Most adverse events belonged to probable category.

CONCLUSION

Vilazodone is more efficacious and well tolerated antidepressant compared to escitalopram and amitriptyline.

Differences Between the Prenatal Effects of Fluoxetine or Buspirone Alone or in Combination on Pain and Affective Behaviors in Prenatally Stressed Male and Female Rats

The selective serotonin reuptake inhibitor fluoxetine and the 5-HT1A receptor agonist buspirone are used to treat depression and anxiety. Previously we demonstrated that chronic stress during pregnancy (prenatal stress) in rats, used as a model of maternal depression risk, increased inflammatory pain and depressive-like behavior in the offspring; buspirone injected to pregnant dams was protective. Clinically, the addition of buspirone to fluoxetine increases the latter’s efficacy in treating depression in patients. Here, we investigated the influence of repeated prenatal injections of fluoxetine, buspirone or their combination on pain- and depressive-like behaviors in prenatally stressed young male and female rats. Prenatal stress augmented depressive-like behavior and both thermal and inflammatory pain (formalin test), replicating our prior findings, and increased basal levels of corticosterone in the blood plasma. Both drugs and their combination reduced the effects of prenatal stress on thermal pain and depressive-like behavior independently of sex. The combination of fluoxetine and buspirone, compared with fluoxetine, was more antinociceptive in the hot plate test in both sexes, and when compared with buspirone, was more antinociceptive only in males. A detailed study of the time-course of formalin-induced pain showed a nuanced effect of these drugs that was sex-dependent. The combination of the two drugs was less effective in females than males during the initial acute phase of nociceptive behavior in flexing + shaking behaviors, whereas that combination was more effective than fluoxetine alone in the first acute phase of licking behavior in females. The antinociceptive effect of buspirone dominated that of the drug combination and of fluoxetine alone, especially during the interphase of the formalin test in both sexes for both flexing + shaking and licking, suggesting a more effective prenatal action of buspirone on the development of a descending serotonergic inhibitory system modulating pain in the spinal cord dorsal horn neurons. Our results indicate that inflammatory pain-like responses integrated at the spinal level in males were more vulnerable to prenatal stress than females. In licking, the antinociceptive effect of fluoxetine and drug combination in the interphase was more in males than females. The data underscore the importance of considering sexual dimorphism when using drug therapy.

New Treatment Options for Depression: A Primer for Internists

Depression continues to be a challenging condition to treat despite the myriad treatment options available. Primary care providers are increasingly tasked with providing second- and third-line treatments for major depressive disorder, and thus, should be familiar with newer medication therapies that are available. In this article, we aim to provide the general internist and other providers who treat depression in their practice with a succinct review of recent developments in the treatment of depression.

Addressing the Side Effects of Contemporary Antidepressant Drugs: A Comprehensive Review

Randomized trials have shown that selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) have better safety profiles than classical tricyclic antidepressants (TCAs). However, an increasing number of studies, including meta-analyses, naturalistic studies, and longer-term studies suggested that SSRIs and SNRIs are no less safe than TCAs. We focused on comparing the common side effects of TCAs with those of newer generation antidepressants including SSRIs, SNRIs, mirtazapine, and bupropion. The main purpose was to investigate safety profile differences among drug classes rather than the individual antidepressants, so studies containing comparison data on drug groups were prioritized. In terms of safety after overdose, the common belief on newer generation antidepressants having fewer side effects than TCAs appears to be true. TCAs were also associated with higher drop-out rates, lower tolerability, and higher cardiac side-effects. However, evidence regarding side effects including dry mouth, gastrointestinal side effects, hepatotoxicity, seizure, and weight has been inconsistent, some studies demonstrated the superiority of SSRIs and SNRIs over TCAs, while others found the opposite. Some other side effects such as sexual dysfunction, bleeding, and hyponatremia were more prominent with either SSRIs or SNRIs.

Five potential therapeutic agents as antidepressants: a brief review and future directions

Despite the availability of numerous antidepressants, many patients with depression do not show adequate response. The therapeutic lag between drug administration and onset of clinical improvement observed with conventional antidepressants has led to a need for antidepressants with a novel mechanism of action. Recently, five such agents, including acetyl-L-carnitine, scopolamine, ω-3 polyunsaturated fatty acids, ketamine, and selective 5-HT7 serotonin receptor antagonists, have gained interest as potential antidepressants with enhanced symptom control, improved tolerability, and faster onset of action compared to conventional antidepressants. This review provides an update and critical examination of these five novel therapeutic agents as potential antidepressants.

Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry

RATIONALE

Vilazodone is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of major depressive disorder (MDD). An extensive literature search found few reports on the in vivo and in vitro metabolism of vilazodone. Therefore, we report a comprehensive in vivo and in vitro metabolic identification and structural characterization of vilazodone using ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS/MS) and in silico toxicity study of the metabolites.

METHODS

To identify in vivo metabolites of vilazodone, blood, urine and faeces samples were collected at different time intervals starting from 0 h to 48 h after oral administration of vilazodone to Sprague-Dawley rats. The in vitro metabolism study was conducted with human liver microsomes (HLM) and rat liver microsomes (RLM). The samples were prepared using an optimized sample preparation approach involving protein precipitation followed by solid-phase extraction. The metabolites have been identified and characterized by using LC/ESI-MS/MS.

RESULTS

A total of 12 metabolites (M1-M12) were identified in in vivo and in vitro matrices and characterized by LC/ESI-MS/MS. The majority of the metabolites were observed in urine, while a few metabolites were present in faeces and plasma. Two metabolites were observed in the in vitro study. A semi-quantitative study based on percentage counts shows that metabolites M11, M6 and M8 were observed in higher amounts in urine, faeces and plasma, respectively.

CONCLUSIONS

The structures of all the 12 metabolites were elucidated by using LC/ESI-MS/MS. The study suggests that vilazodone was metabolized via hydroxylation, dihydroxylation, glucuronidation, oxidative deamination, dealkylation, dehydrogenation and dioxidation. All the metabolites were screened for toxicity using an in silico tool.

Shortened Spadin Analogs Display Better TREK-1 Inhibition, In Vivo Stability and Antidepressant Activity

Depression is a devastating mental disorder that affects 20% of the population worldwide. Despite their proven efficacy, antidepressants present a delayed onset of action and serious adverse effects. Seven years ago, we described spadin (PE 12-28) as a promising endogenous peptide with antidepressant activity. Spadin specifically blocks the TREK-1 channel. Previously, we showed in vivo that, spadin activity disappeared beyond 7 h after administration. In order to improve in vivo spadin stability and bioavailability, we screened spadin analogs and derivatives. From the study of spadin blood degradation products, we designed a 7 amino-acid peptide, PE 22-28. In vitro studies on hTREK-1/HEK cells by using patch-clamp technique, showed that PE 22-28 displayed a better specificity and affinity for TREK-1 channel compared to spadin, IC₅₀ of 0.12 nM vs. 40–60 nM for spadin. In the same conditions, we also pointed out that different modifications of its N or C-terminal ends maintained or abolished TREK-1 channel activity without affecting PE 22-28 affinity. In vivo, the antidepressant properties of PE 22-28 and its derivatives were demonstrated in behavioral models of depression, such as the forced swimming test. Mice treated with spadin-analogs showed a significant reduction of the immobility time. Moreover, in the novelty suppressed feeding test after a 4-day sub-chronic treatment PE 22-28 reduced significantly the latency to eat the food pellet. PE 22-28 and its analogs were able to induce neurogenesis after only a 4-day treatment with a prominent effect of the G/A-PE 22-28. On mouse cortical neurons, PE 22-28 and its derivatives enhanced synaptogenesis measured by the increase of PSD-95 expression level. Finally, the action duration of PE 22-28 and its analogs was largely improved in comparison with that of spadin, up to 23 h instead of 7 h. Taken together, our results demonstrated that PE 22-28 and its derivatives represent other promising molecules that could be an alternative to spadin in the treatment of depression.

Efficacy and tolerability of vilazodone for the acute treatment of generalized anxiety disorder: A meta-analysis

PURPOSE

A systematic review and meta-analysis of all relevant randomized controlled trials was conducted to evaluate the safety and efficacy of vilazodone in the acute treatment of generalized anxiety disorder (GAD).

METHODS

The literature was searched through all relevant databases in order to identify clinical trials on the use of vilazodone in the treatment of GAD. Once the trials were identified, data was extracted and analyzed using Revman5.3 and open meta-analyst. Assessment of continuous outcomes relied upon standardized mean difference, while binary outcomes were evaluated via relative risk, absolute risk reduction and NNT/NNH.

RESULTS

A total of 3 well-designed randomized controlled trials with a duration of 10 weeks were conducted, with a total of 844 (intent to treat population) randomized to vilazodone (20-40mg, mean dose=31.42mg) and 618 to placebo. The study drug was significantly superior (p<0.001) to placebo in continuous primary outcome measures (HAMA reduction at week 8, CGI-S reduction at week 8 and CGI-I score at week 8). Binary outcome measures however are not as promising, probably reflecting a small effect size [NNT=10 (6.67, 21.28) for induction of response according to the HAMA scale and NNT=12 (7.58, 34.48) for the CGI-I scale], although statistical significance (p<0.01) was attained for both. The study drug was significantly (p<0.001) more likely than placebo to induce adverse effects and to be discontinued due to adverse effects NNH=14 (10.31, 22.22), most common of which were nausea and diarrhea.

DISCUSSION

Vilazodone was superior to placebo in the short term treatment of GAD. However, due to the small effect size and high incidence of adverse events, the utility of vilazodone in the treatment of GAD remains unclear. Likelihood to be helped (HAMA response) or harmed (discontinuation due to adverse events) was inconclusive [1.4 (0.48, 3.33)], demonstrating a need for further trials and direct comparisons of vilazodone to the standard treatments for the disorder. Thus vilazodone cannot be recommended yet as a first line agent.

CONCLUSION AND LIMITATIONS

Vilazodone is an effective treatment for generalized anxiety disorder, though further trials are required for a more adequate comparison with established treatments, as well as long term maintenance studies to determine the validity of claims regarding the absence of sexual side effects.

New drugs in psychiatry: focus on new pharmacological targets

The approval of psychotropic drugs with novel mechanisms of action has been rare in recent years. To address this issue, further analysis of the pathophysiology of neuropsychiatric disorders is essential for identifying new pharmacological targets for psychotropic medications. In this report, we detail drug candidates being examined as treatments for psychiatric disorders. Particular emphasis is placed on agents with novel mechanisms of action that are being tested as therapies for depression, schizophrenia, or Alzheimer’s disease. All of the compounds considered were recently approved for human use or are in advanced clinical trials. Drugs included here are new antipsychotic medications endowed with a preferential affinity at dopamine D3 receptor (cariprazine) or at glutamatergic or cannabinoid receptors, as well as vortioxetine, a drug approved for managing the cognitive deficits associated with major depression. New mechanistic approaches for the treatment of depression include intravenous ketamine or esketamine or intranasal esketamine. As for Alzheimer’s disease, the possible value of passive immunotherapy with agents such as aducanumab is considered to be a potential disease-modifying approach that could slow or halt the progressive decline associated with this devastating disorder.

Vilazodone for the Treatment of Depression: An Update

Vilazodone is a novel antidepressant having a selective serotonin (5-HT) reuptake inhibitor and 5-HT1A receptor partial agonist profile, so it has been regarded as a serotonin partial agonist-reuptake inhibitor (SPARI). We aimed to provide Vilazodone's clinical implications mainly by reviewing published clinical trials. Vilazodone has been speculated to have three potential benefits including faster onset of action, greater efficacy, and better tolerability owning to its SPARI properties. However, no studies conducted so far have directly proven the above speculations. Five initial phase II trials failed to distinguish vilazodone from placebo in the treatment of MDD, but 4 randomized clinical trials (RCT), 3 post-hoc or pooled analysis, 1 long-term open label study, and a meta-analysis showed vilazodone's superior efficacy over placebo. The studies also showed vilazodone is generally safe and tolerable. However, diarrhea, nausea, headache, dizziness, dry mouth, and insomnia warrant close attention in clinical practice because they have been constantly noted throughout the clinical studies. 2 RCTs recently documented the efficacy and safety of vilazodone in patients with generalized anxiety disorder, which could be a start of broadening vilazodone's usage or FDA approval in diverse anxiety disorders.

Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice

Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD.

Aripiprazole augmentation versus antidepressant switching for patients with major depressive disorder: A 6-week, randomized, rater-blinded, prospective study

No study has directly compared the efficacy and tolerability of aripiprazole augmentation (AA) and antidepressant switching (SW) in patients with major depressive disorder (MDD). This is the first 6-week, randomized, rater-blinded, direct comparison study between AA and SW in outpatients. An inadequate response to antidepressants was defined as a total score ≥ 14 on the Hamilton Depression Rating Scale-item 17 (HDRS-17) despite adequate antidepressant dosage for at least 6 weeks in the current depressive episode. The primary endpoint was change in the total score of the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to the end of treatment. Secondary efficacy measures included the response and remission rates as priori defined at the end of treatment: changes in total scores of the HDRS-17, Iowa Fatigue Scale (IFS), and Sheehan Disability Scale (SDS) from baseline to the end of treatment and the proportion of patients who scored 1 or 2 on the Clinical Global Impression-Improvement Score (CGI-I) at the end of treatment. Tolerability was assessed with the Barnes Akathisia Rating Scale (BARS) and Arizona Sexual dysfunction scale (ASEX), and the numbers of adverse events were compared between the two groups. A total of 101 patients were randomized to either AA (n = 52) or SW (n = 49). The mean change in the MADRS score from baseline was significantly higher in the AA, with a difference in magnitude of -8.7 (p < 0.0001). The intergroup difference was first evident in week 2. The numbers of responders (p = 0.0086) and remitters (p = 0.0005) were also significantly higher in the AA (60% and 54%, respectively) compared with the SW (32.6% and 19.6%, respectively). On most secondary endpoints, AA showed better clinical outcomes compared to SW. The tolerability profiles were comparable between the two groups. Overall, AA yielded potentially beneficial clinical outcomes compared to SW. Given the methodological shortcomings of the present study, adequately powered, more rigorously controlled clinical trials are strongly warranted to confirm the present findings.

Evaluation of the efficacy and safety of vilazodone for treating major depressive disorder

PURPOSE

Vilazodone is a novel serotonin (5-HT)-reuptake inhibitor and 5-HT1A partial agonist that was recently developed for the treatment of major depressive disorder (MDD). We conducted a meta-analysis and systematic review to better evaluate the efficacy and safety of vilazodone.

MATERIALS AND METHODS

We performed a thorough literature search to identify all randomized double-blind placebo-controlled trials that were designed to investigate the efficacy of vilazodone for the treatment of MDD, and that were published in electronic databases, including Medline, Embase, and the Cochrane Central Register of Controlled Trials. A manual search was also conducted to investigate the relevant references of the retrieved studies. Subsequently, we conducted a meta-analysis and systematic literature review.

RESULTS

A total of five randomized controlled trials were finally included, involving 1,200 patients with vilazodone and 1,193 patients with placebo. The primary efficacy end point of the Montgomery-Åsberg Depression Rating Scale (standardized mean difference -3.58, 95% confidence interval -4.59 to -2.56; P<0.00001), and the key secondary efficacy end points (Clinical Global Impression - Severity scale, Clinical Global Impression - Improvement scale, and Hamilton Anxiety Rating Scale) indicated that vilazodone was more effective than placebo. Most common adverse events, including diarrhea and nausea, were evaluated, and safety assessments indicated that vilazodone was well tolerated (diarrhea odds ratio 3.54, 95% confidence interval 2.81-4.45; P<0.00001; nausea odds ratio 3.85, 95% confidence interval 3.00-4.96; P<0.00001; discontinuations due to adverse events odds ratio 2.71, 95% confidence interval 1.81-4.05; P<0.00001).

CONCLUSION

Our findings indicate that the novel antidepressant vilazodone is effective and safe for MDD, with a low occurrence of side effects. It offers promise as an effective oral drug for the treatment of MDD, with a balance of efficacy and tolerability.