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.

Vilazodone, a Selective Serotonin Reuptake Inhibitor with Diminished Impact on Methylphenidate-Induced Gene Regulation in the Striatum: Role of 5-HT1A Receptor

Selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, are frequently combined with medical psychostimulants such as methylphenidate (Ritalin), for example, in the treatment of attention-deficit hyperactivity disorder/depression comorbidity. Co-exposure to these medications also occurs with misuse of methylphenidate as a recreational drug by patients on SSRIs. Methylphenidate, a dopamine reuptake blocker, produces moderate addiction-related gene regulation. Findings show that SSRIs such as fluoxetine given in conjunction with methylphenidate potentiate methylphenidate-induced gene regulation in the striatum in rats, consistent with a facilitatory action of serotonin on addiction-related processes. These SSRIs may thus increase methylphenidate's addiction liability. Here, we investigated the effects of a novel SSRI, vilazodone, on methylphenidate-induced gene regulation. Vilazodone differs from prototypical SSRIs in that, in addition to blocking serotonin reuptake, it acts as a partial agonist at the 5-HT1A serotonin receptor subtype. Studies showed that stimulation of the 5-HT1A receptor tempers serotonin input to the striatum. We compared the effects of acute treatment with vilazodone (10-20 mg/kg) with those of fluoxetine (5 mg/kg) on striatal gene regulation (zif268, substance P, enkephalin) induced by methylphenidate (5 mg/kg), by in situ hybridization histochemistry combined with autoradiography. We also assessed the impact of blocking 5-HT1A receptors by the selective antagonist WAY-100635 (0.5 mg/kg) on these responses. Behavioral effects of these drug treatments were examined in parallel in an open-field test. Our results show that, in contrast to fluoxetine, vilazodone did not potentiate gene regulation induced by methylphenidate in the striatum, while vilazodone enhanced methylphenidate-induced locomotor activity. However, blocking 5-HT1A receptors by WAY-100635 unmasked a potentiating effect of vilazodone on methylphenidate-induced gene regulation, thus confirming an inhibitory role for 5-HT1A receptors. Our findings suggest that vilazodone may serve as an adjunct SSRI with diminished addiction facilitating properties and identify the 5-HT1A receptor as a potential therapeutic target to treat addiction.

SSRIs in the Treatment of Depression: A Pharmacological CUL-DE-SAC?

The widespread adoption of selective serotonin reuptake inhibitors (SSRIs) as first-line pharmacological treatments in the management of clinical depression transformed the landscape of drug therapy for this condition. SSRIs are safer and better tolerated than the tricyclic antidepressants (TCAs) that they replaced. However, they have limitations that may have placed a ceiling on the expectations of first-line pharmacological treatment. Notable problems with SSRIs include induction of anxiety on treatment initiation, delayed onset of significant therapeutic effect, sexual dysfunction, sleep disturbance and overall modest efficacy. The latter is linked with an inability of SSRIs to effectively treat syndromes of anhedonia and cognitive impairment. Combined serotonin and noradrenaline reuptake inhibitors (SNRIs), such as venlafaxine, have produced some limited improvements over SSRIs in efficacy, at the cost of a greater side-effect burden. Attempts to supplement serotonin reuptake activity with actions at serotonin receptor sub-types have not yet yielded substantial benefits; however, vortioxetine may provide more utility in the management of cognitive impairment. Future advances might come from the development of SNRIs, which more closely mimic the actions of effective TCAs. There may also be possible benefits to be derived from combining SSRIs with 5-HT4 receptor agonists and 5-HT7 receptor antagonists.

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.

Relative frequency of drug-induced sleep disorders for 32 antidepressants in a large set of Internet user reviews

STUDY OBJECTIVES

It is known that antidepressant drugs can induce sleep disorders in patients, but little data exist about high or low-risk molecules. The aim was to study the frequency of antidepressant drugs-induced sleep disorders (DISD) by molecule.

METHODS

77,391 patient comments for 32 antidepressant drugs were collected from drug review websites and screened for DISD. Association between drugs and nightmare disorder, restless legs syndrome, sleep paralysis, sleep terrors, sleep-related hallucinations or sleep walking was expressed as relative proportion [proportional reporting ratio (PRR)]. A detailed analysis of the dreams content was also carried out.

RESULTS

Amitriptyline, doxepin, fluvoxamine, mirtazapine, nortriptyline, trazodone, venlafaxine and vilazodone were associated with a greater frequency of DISD compared to other antidepressants. Vilazodone heavily increased the probability of developing 5 of the 6 studied DISD (PRR 3.3 to 19.3) and mirtazapine increased the probability for developing 4 DISD (PRR 2.4 to 6.4). Bupropion and citalopram were associated with lower probabilities for 5 DISD (PRR 0.2 to 0.7). Sentiment analysis showed that patients described disturbing dreams for vilazodone or mirtazapine and strange but less negative dreams for bupropion, citalopram or duloxetine.

CONCLUSIONS

Relative frequencies of sleep disorders were obtained for a vast panel of antidepressant drugs through an original analysis of user's drug reviews on drug rating websites. Our results could guide clinicians in appropriate choice of antidepressant drug for high DISD-risk patients in need of such treatment. These results may however be cautiously taken, considering the uncertain reliability and generalisability of web-based data.

Spectrofluorimetric determination of tianeptine using its quenching effect on Vilazodone

A rapid, cost effective, simple and reliable method was developed for the determination of Tianeptine (TIA) drug in bulk and in pharmaceutical formulation. The fluorescence of Vilazodone was measured in isopropanol at room temperature. The method was optimized by measuring the factors that may affect the fluorescence intensity such as: pH, diluting solvent, temperature and mixing time. The developed method was validated according to ICH guidelines in terms of accuracy, precision, linearity, range, LOD and LOQ. The concentration range was found to be linear in the range of 10-100 ng/ml. The LOD and LOQ values were found to be very small (1.86, 5.62 ng/mL. The % RSD and the % R were found within the acceptable range. Unlike the HPLC procedures, the proposed method for TIA determination has many advantages over the reported analytical methods represented in its rapidity, lower cost and environmental safety as the instrument is simple with low operating cost.

Development of severe serotonin syndrome from acute ingestion of vilazodone without co-ingestion

Vilazodone is a selective serotonin reuptake inhibitor (SSRI) that was introduced to the market in 2011. It has a novel mechanism combining serotonin reuptake and partial agonism of 5HT-1 receptors. It has gained popularity in treating first generation SSRI-resistant depression. There has been little description in the literature of adult overdose. We are describing a 21-year-old female with an intentional overdose of 400 mg of vilazodone. This patient progressively developed worsening serotonin syndrome, which was resistant to aggressive benzodiazepine administration. The patient required sedation with propofol and phenobarbital to control serotonin syndrome. Patient required continued sedation for 36 h post-ingestion, with subsequent extubation and return to normal mental status. We detail an atypical case of a novel SSRI overdose with the treatment regimen used.

Diverse serotonin actions of vilazodone reduce l-3,4-dihidroxyphenylalanine-induced dyskinesia in hemi-parkinsonian rats

BACKGROUND

The serotonergic system is a well-established modulator of l-dopa-induced dyskinesia. To date, targeting serotonin transporters or serotonin receptor subtype 1A (5-HT_1A ) reduces l-dopa-induced dyskinesia in animal models; however, these strategies have failed to translate clinically. Ideally, a compound acting at both known antidyskinetic sites could optimize serotonin-mediated approaches. Vilazodone is a selective serotonin reuptake inhibitor and a partial 5-HT_1A agonist approved by the U.S. Food and Drug Administration, situating Vilazodone in a unique position to reduce l-dopa-induced dyskinesia without compromising l-dopa-mediated motor improvements.

OBJECTIVES

The goal of the present study was to characterize Vilazodone's effects on l-dopa-induced behaviors, neurochemistry and gene expression in unilateral 6-hydroxydopamine-lesioned hemi-parkinsonian rats.

METHODS

In experiments 1 and 2, l-dopa-naïve and l-dopa-primed animals were coadministered Vilazodone and l-dopa daily for 3 weeks to model subchronic use, and behavioral, neurochemical, and messenger RNA (mRNA) expression changes were measured. In experiment 3, dyskinetic behavior was assessed following 5-HT_1A or serotonin receptor subtype 1B blockade prior to Vilazodone-l-dopa coadministration.

RESULTS

Vilazodone significantly suppressed developing and established l-dopa-induced dyskinesia without compromising the promotor effects of l-dopa therapy. In the dopamine-depleted striatum, Vilazodone-l-dopa cotreatment increased dopamine content, suggesting a normalization of dopamine kinetics in dyskinetic brain, and reduced l-dopa-induced c-Fos and preprodynorphin mRNA overexpression, indicative of attenuated dopamine D₁ receptor-mediated direct pathway overactivity. Only 5-HT_1A antagonism partially attenuated Vilazodone's antidyskinetic efficacy, suggesting both serotonin transporter-dependent effects and 5-HT_1A receptors in Vilazodone's actions.

CONCLUSIONS

Our findings show Vilazodone has a serotonin-dependent effect on rodent l-dopa-induced dyskinesia and implicate the potential for repositioning Vilazodone against l-dopa-induced dyskinesia development and expression in Parkinson's disease patients. © 2018 International Parkinson and Movement Disorder Society.

Other Antidepressants

This chapter addresses the following FDA-approved medications for the treatment of major depressive disorder available for use in the United States including bupropion, mirtazapine, trazodone, vortioxetine, and vilazodone. These medications do not belong to one of the previously featured classes of antidepressants discussed in the preceding chapters. Each medication featured in this chapter has a unique structure and properties that target diverse receptors in the central nervous system. These diverse targets are distinct from other classes of medications used to treat major depressive disorder. This chapter will provide an overview of each medication's indication for use, history of development, pharmacology, metabolism, dosing recommendations, onset of action, use in special populations, safety and tolerability, adverse effects, potential interactions with additional medications, and data regarding possible overdose with available treatments.Bupropion was initially developed for its combined effects on the norepinephrine and dopamine neurotransmitters. Currently, bupropion is the only antidepressant on the market in the United States with no appreciable activity on serotonin concentrations in the central nervous system. Bupropion is extensively metabolized in humans into three active metabolites including hydroxybupropion, threohydrobupropion, and erythrohydrobuproprion each with substantial antidepressant activity. The most serious side effect of bupropion is the development of seizures, so the dose must be gradually titrated to a maximum dose of 450 mg per day of the immediate-release formulation and 400 mg per day of the sustained-release formulation. Additional adverse effects include agitation, dry mouth, insomnia, headaches, migraines, nausea, vomiting, constipation, and tremor. The onset of action of bupropion is 2 weeks with full efficacy attained at 4 weeks of treatment. Bupropion produced similar depression remission rates when compared to SSRIs with a median time to relapse of 44 weeks. Bupropion has additionally been approved for smoking cessation and may have a combined role in treating nicotine cravings and depression.Mirtazapine has a unique method of action by enhancing norepinephrine and serotonin neurotransmission by blocking the alpha-2 presynaptic adrenoceptors resulting in increased release of serotonin at the nerve terminals. Mirtazapine additionally binds to the 5-HT₂, 5-HT₃, and H₁ receptors resulting in increased sedation, which is the most common side effect. Additional side effects include increased appetite and weight gain, dizziness, and transient elevations in cholesterol levels and liver function tests. Mirtazapine is unlike any other antidepressant in that it also has a hormonal effect that reduces cortisol levels within the body. Patients on mirtazapine showed significant improvement in symptoms of major depressive disorder within the first 1-2 weeks of treatment with long-term studies at 40 weeks showing continued improvements in response rates in addition to lower relapse rates. Mirtazapine has an antagonistic effect at the central presynaptic 5-HT₂ receptors and alpha-2 adrenergic inhibitory autoreceptors and heteroreceptors resulting in increased norepinephrine release with an indirect release of serotonin due to increased noradrenergic input to the raphe nucleus. Mirtazapine has an effective dose range from 15 to 45 mg once daily with a long half-life preventing dose adjustments more often than every 1-2 weeks.Trazadone is a 5-HT_2A and 5-HT_2C receptor antagonist and selective serotonin reuptake inhibitor. While trazodone has only been FDA approved for use in the treatment of major depressive disorder, it has been used off label for numerous conditions including insomnia, anxiety, dementia, Alzheimer's disease, substance abuse, schizophrenia, bulimia, and fibromyalgia. The most common adverse reaction is drowsiness, followed by dizziness, dry mouth, and nervousness. In the United States, trazadone is the second most commonly prescribed agent used to treat insomnia. The hypnotic action of this medication at lower doses is attributed primarily to the antagonism of the 5-HT_2A receptors, H₁ receptors, and alpha-1 adrenergic receptors. The most active metabolite is m-chlorophenylpiperazine produced by the CYP_3A4 enzyme, which is a more profound inhibitor of serotonin reuptake as compared to the parent molecule of trazadone. The maximum outpatient dose should not exceed 400 mg per day in divided doses, but in hospitalized patients, the dose may be increased to a maximum dose of 600 mg daily in divided doses while the patient is being actively monitored for side effects. One third of inpatients and one half of outpatients had a significant therapeutic response to trazadone by the end of the first week with the remainder of patients responding in 2-4 weeks of therapy.Vortioxetine is a novel antidepressant classified by the World Health Organization as a N06AX antidepressant that was derived from studies targeting the combination of direct serotonin transporter inhibition and 5-HT_1A receptor modulation leading to rapid desensitization of the somatodendritic 5-HT_1A autoreceptors and activation of the postsynaptic 5-HT_1A receptors. This medication is an antagonist at 5-HT₃, 5-HT_1D, and 5-HT₇ receptors, an agonist at 5-HT_1A receptors, and a partial agonist at 5-HT_1B receptors. Blockade of the 5-HT₃ receptor was noted to produce increased levels of serotonin, dopamine, norepinephrine, acetylcholine, and histamine in the prefrontal cortex and hippocampus, which are known to be associated with the development of depression. The most common adverse effect is nausea followed by sexual dysfunction, constipation, and vomiting. The maximum dose of vortioxetine is 20 mg daily with improvement in symptoms of depression noted at 2 weeks with a full therapeutic effect observed at 4-6 weeks.Vilazodone is a selective serotonin reuptake inhibitor and 5-HT_1A receptor partial agonist. This medication works by enhancing serotonergic activity in the central nervous system through selective inhibition of serotonin reuptake with no significant effects noted on norepinephrine or dopamine uptake. Vilazodone additionally binds with high affinity to the 5-HT_1A receptors as a partial agonist resulting in faster onset of action, greater efficacy, and better tolerability with reduced sexual side effects when compared to other SSRIs. The most common adverse effects were diarrhea, nausea, vomiting, and insomnia. Additional reported adverse effects included dizziness, dry mouth, fatigue, abnormal dreams, decreased libido, arthralgias, and palpitations which were self-limited with resolution in 4-5 days after starting the medication. The recommended therapeutic dose of vilazodone is 40 mg daily with improvement noted in depressive symptoms within 1 week of initiating therapy with increased remission rates noted at 6 weeks of therapy.The medications featured in this chapter do not fall within the major categories of antidepressant classes but add additional unique mechanisms for the treatment of major depressive disorder. Each medication targets different receptors in the central nervous system involved in the development of depression. Resolution of depressive symptoms and response rates of these medications are similar to SSRIs with reduced side effects that can often lead to discontinuation of therapy. Use of these unique medications allows clinicians to target specific symptoms and comorbidities often associated with depression resulting in improved symptom resolution and long-term maintenance of remission.

Efficacy and safety of levomilnacipran, vilazodone and vortioxetine compared with other second-generation antidepressants for major depressive disorder in adults: A systematic review and network meta-analysis

BACKGROUND

Second-generation antidepressants dominate the medical management of major depressive disorder (MDD). Levomilnacipran, vilazodone and vortioxetine are the latest therapeutic options approved for the treatment of MDD. This systematic review aims to compare the benefits and harms of vilazodone, levomilnacipran, and vortioxetine with one another and other second-generation antidepressants.

METHODS

We searched electronic databases up to September 2017 and reviewed reference lists and pharmaceutical dossiers to detect published and unpublished studies. Two reviewers independently screened abstracts and full text articles, and rated the risk of bias of included studies. Randomized controlled trials (RCTs) and controlled observational studies including adult outpatients with MDD were eligible for inclusion. We conducted network meta-analyses on response to treatment using frequentist multivariate meta-analyses models. Placebo- and active-controlled trials were eligible for network meta-analyses.

RESULTS

Twenty-four studies met our inclusion criteria. Direct comparisons were limited to vilazodone versus citalopram, and vortioxetine versus duloxetine, paroxetine, or venlafaxine XR (extended release). Results of head-to-head trials and network meta-analyses, overall, indicated similar efficacy among levomilnacipran, vilazodone, or vortioxetine and other second-generation antidepressants. Although rates of overall adverse events and discontinuation due to adverse events were similar, RCTs reported several differences in specific adverse events. For most outcomes the strength of evidence was low.

LIMITATIONS

Limitations are the focus of literature searches on studies published in English, possible reporting biases, and general methodological limitations of network meta-analyses.

CONCLUSIONS

Overall, the available evidence does not indicate greater benefits or fewer harms of levomilnacipran, vilazodone, and vortioxetine compared with other second-generation antidepressants.

Selective Serotonin Reuptake Inhibitors

The first antidepressants were created by chance but brought the idea that central serotonin agonism produced an antidepressant effect. SSRIs were the first class of psychotropic medications to be rationally designed, meaning that researchers intended to utilize a specific mechanism of action while avoiding adverse effects. In this way, SSRIs were created to be safer and more tolerable than previous antidepressants. SSRIs share many similarities, but differ in terms of pharmacokinetics and effects on CYP450 enzymes, which is detailed in this chapter. Further information will be provided regarding safety, clinical indications/uses, and dosing recommendations.

Efficacy and tolerability of different doses of three new antidepressants for treating major depressive disorder: A PRISMA-compliant meta-analysis

In last decade, the US FDA has approved three new antidepressants: vortioxetine, levomilnacipran, and vilazodone. Many studies have researched the effects of these antidepressants on major depressive disorder (MDD), but they have not determined the optimum dosage. This meta-analysis investigated the efficacies of these three drugs at different dosages in the treatment of MDD. The PubMed, Embase, Cochrane Library, psycINFO, and ClinicalTrials.gov databases were searched to identify relevant literature. The primary outcomes were efficacy [quantified as the change from baseline in total score on the Montgomery-Asberg Depression Rating Scale (MADRS)] and tolerability (discontinuations due to adverse events). The effect size was quantified as the weighted mean difference for continuous data and the risk ratio (RR) for dichotomous data. Overall 22 studies were included. The changes in the MADRS total score were significantly higher for vortioxetine at 5, 10, 20, and 10-20 mg/day than for placebo. The tolerability was significantly worse for 20 mg/day vortioxetine than for placebo (RR = 1.84, 95% confidence interval = 1.13 to 3.02). In addition, increasing the dosage improved the efficacy of vortioxetine but worsened the tolerability. Levomilnacipran and vilazodone at any dosage produced a significantly higher mean change from baseline in the MADRS total score and a worse tolerability than for placebo. In conclusion, considering both efficacy and tolerability, 10 mg/day vortioxetine might be optimal for the treatment of MDD. The long-term efficacy and safety of vortioxetine needed to be investigated, and more studies of levomilnacipran and vilazodone are needed to define their optimal dosages.

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.

Differential effects of vilazodone versus citalopram and paroxetine on sexual behaviors and serotonin transporter and receptors in male rats

RATIONALE

Sexual side effects are commonly associated with selective serotonin reuptake inhibitor (SSRI) treatment. Some evidence suggest that activation of 5-HT1A receptors attenuates SSRI-induced sexual dysfunction.

OBJECTIVE

This study in male rats compared the effects of vilazodone, an antidepressant with SSRI and 5-HT1A receptor partial agonist activity, with other prototypical SSRIs (citalopram and paroxetine) on sexual behaviors and 5-HT receptors (5-HT1A and 5-HT2A) and transporter (5-HTT) levels in select forebrain regions of the limbic system using quantitative autoradiography.

METHODS

Rats received vilazodone (1, 3, and 10 mg/kg), citalopram (10 and 30 mg/kg), or paroxetine (10 mg/kg) treatment for 14 days. Sexual behaviors (frequency and latency of mounts, intromissions, and ejaculations) were measured in the presence of an estrous female rat on days 1 (acute), 7 (subchronic), and 14 (chronic).

RESULTS

Vilazodone-treated rats exhibited no sexual dysfunction compared with controls; in contrast, the citalopram- and paroxetine-treated rats exhibited impaired copulatory and ejaculatory behaviors after subchronic and chronic treatments. Chronic vilazodone treatment markedly decreased 5-HT1A receptor levels in cortical and hippocampal regions, while the SSRIs increased levels of this receptor in similar regions. All chronic treatments reduced 5-HTT levels across the forebrain; however, the magnitude of the decrease was considerably smaller for vilazodone than for the SSRIs.

CONCLUSIONS

The current studies showed that chronic treatment with vilazodone, in contrast to citalopram and paroxetine, was not associated with diminished sexual behaviors in male rats, which may be related to the differential effects of vilazodone on 5-HT1A receptor and 5-HTT levels relative to conventional SSRIs.

American Psychiatric Association - 168th Annual Meeting (May 16-20, 2015 - Toronto, Canada)

The theme of this year's American Psychiatric Association (APA) meeting was 'Psychiatry: integrating body and mind, heart and soul', with special focus given to advances in basic and cognitive neuroscience and how these may contribute to integrated care of mental health and illness. The program featured numerous tracks and subtracks in areas of interest such as addiction psychiatry, child, adolescent and geriatric psychiatry, and psychosomatic medicine.

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

We tried to review and update clinical and preclinical studies evaluating vilazodone's role as an antidepressant for patients with major depressive disorder (MDD). In terms of its mechanism of actions, we sought to elaborate them mainly through preclinical animal studies. A data search was conducted in November 1, 2013, using the key terms "vilazodone" or "Viibryd," in PubMed and Medline databases. All published and unpublished studies are included and citations from publications were also reviewed for additional references. Five unpublished, phase-II and two pivotal published phase-III clinical trials with nearly identical design (8-week, double-blind, randomized, and placebo-controlled) investigated efficacy of vilazodone, were found for the treatment of patients with MDD. Two post-hoc studies and one long-term open study were also included. Data were thoroughly reviewed to incorporate the pharmacology, action mechanism, efficacy and safety for the vilazodone in the treatment of major depressive disorder. Vilazodone is an antidepressant with novel mechanism of action because its chemical structure is unrelated to conventional antidepressant, and it has a selective serotonin (5-HT) reuptake inhibitor and 5-HT1A receptor partial agonist profile. Vilazodone is an effective and safe treatment option with its novel action mechanisms for patients with depression. Its putative benefits compared with other antidepressants must be thoroughly studied in adequately-powered and well-designed future clinical trials.

Health resource use and costs of vilazodone and other selective serotonin re-uptake inhibitors in treating major depressive disorder

OBJECTIVE

Selective serotonin re-uptake inhibitors (SSRIs) are widely prescribed antidepressants. This claims database study compared healthcare resource use and costs among patients with major depressive disorder (MDD) treated with vilazodone vs other SSRIs.

METHODS

Adults with an MDD diagnosis and ≥ 1 prescription fill for vilazodone, citalopram, escitalopram, fluoxetine, paroxetine, or sertraline were identified from administrative claims data (2010-2012). Patients who concomitantly used adjunctive medication, either a second-generation antidepressant or antipsychotic, were excluded. All-cause and MDD-related healthcare resource use and costs (in 2012 USD) were compared between patients treated with vilazodone vs other SSRIs over a 6-month follow-up period using unadjusted and multivariable analyses.

RESULTS

The study cohort included 49 861 patients (mean age = 44.0 years; 70% female). Compared with the vilazodone cohort (n = 3527), patients in the citalopram (n = 12 187), escitalopram (n = 8275), fluoxetine (n = 10 142), paroxetine (n = 3146), and sertraline (n = 12 584) cohorts had significantly more all-cause inpatient hospital visits, longer hospital stays and more frequent emergency department visits, following the index date, after adjusting for baseline characteristics. All-cause medical service costs (inpatient + outpatient + emergency department visits) were significantly higher across all other SSRI cohorts vs vilazodone by $758-$1165 (p < 0.05). Similarly, all-cause total costs, were significantly or numerically (non-significantly) higher across all SSRI cohorts vs vilazodone by $351-$780.

LIMITATIONS

The was no clinical measurement of disease severity, partial coverage of the Medicare-eligible population, and short follow-up.

CONCLUSION

MDD treatment with vilazodone was associated with significantly lower rates of inpatient and emergency services, and with significantly lower all-cause medical service costs and numerically (non-significantly) lower total costs to payers than with the other SSRIs included in this study.