Evaluation of vilazodone for the treatment of depressive and anxiety disorders

Introduction: Major Depressive Disorder (MDD) and General Anxiety Disorder (GAD) significantly contribute to the global burden of disease. Vilazodone, a combined serotonin reuptake inhibitor and 5-HT1A partial agonist, is an approved therapy for the treatment of MDD and which has been further investigated for GAD.

Areas covered: This article covers the pharmacokinetics and pharmacodynamics of vilazodone and provides an evaluation of the clinical usefulness of vilazodone for the treatment of MDD and anxiety disorders. A literature search was performed using PubMed/MEDLINE, Web of Science and the Cochrane Library.

Expert opinion: Studies have shown that vilazodone is significantly superior to placebo. However, vilazodone cannot as yet be recommended as a first-line treatment option for MDD as it is unclear whether the drug’s dual mechanism of action provides greater efficacy than prevailing treatment options. Moreover, more phase IV studies are needed to establish its efficacy and long-term safety in larger and more diverse populations. Although vilazodone may have an additional advantage for the treatment of anxiety symptoms in MDD, here also additional studies are required to confirm its efficacy over and above SSRI alternatives and other antidepressant treatments. Therefore, presently, vilazodone should be considered as a second- or third-line treatment option for MDD and GAD.     

Brand-Name Antidepressants Outperform Their Generic Counterparts in Preventing Hospitalization for Depression: The Real-World Evidence from Taiwan

BackgroundGeneric antidepressants are approved on the market based on evidence of bioequivalence to their brand-name versions. We aimed to assess whether generic antidepressants exert equal effectiveness as their brand-name counterparts for treating patients with depressive disorders.MethodsIn a nationwide, population-based cohort in Taiwan from 1997 through 2013, patients with a diagnosis of a depressive disorder aged between 18 and 65 years who were new users of antidepressant drugs were classified into either the brand-name group or the generic group. All patients were followed up until medication discontinuation or the end of the study period. We assessed the risk for hospitalization as a primary outcome and augmentation therapy, daily dose, medication discontinuation, or switching to another antidepressant as secondary outcomes.ResultsA total of 277 651 brand-name users (35.8% male; mean age: 41.2 years) and 270 583 generic users (35.8% male; mean age: 41.0 years) were divided into 10 different antidepressant groups (fluoxetine, sertraline, paroxetine, escitalopram, citalopram, venlafaxine, mirtazapine, moclobemide, imipramine, and bupropion). We found that patients treated with the generic form of sertraline, paroxetine, escitalopram, venlafaxine, mirtazapine, and bupropion demonstrated significantly higher risks of psychiatric hospitalization (adjusted hazard ratios ranged from 1.20–2.34), compared to their brand-name counterparts. The differences between brand-name antidepressants and their generic counterparts in secondary outcomes varied across different drugs.ConclusionsCompared to most generic antidepressants, brand-name drugs exhibited more protective effects on psychiatric hospitalization for depressive patients. These findings could serve as an important reference for clinicians when encountering patients with depressive disorder.     

Brain-derived neurotrophic factor and post-stroke depression

Brain-derived neurotrophic factor (BDNF) is well known to play a critical role in cognition. Its role in mood disorders, including post stroke depression (PSD), is also recognized with more evidence surfacing. In patients with PSD, their serum BNDF level is lower than in those without depression. Furthermore, antidepressants could enhance BDNF expression in the brain, resulting in an alleviation of depression symptoms. Such therapeutic effect can be abolished in animals with the BDNF gene deleted. In PSD patients, the presence of stroke may contribute to the development of depression, including affecting the expression of BDNF. However, the mechanisms of BDNF in the development of PSD remain largely unknown. Lower BDNF levels may have existed in some patients before stroke onset, making them vulnerable to develop depressive symptoms. Meanwhile, the hypoxic environment induced by stroke could possibly downregulate BDNF expression in the brain. Current antidepressant treatments are not specific for PSD and there is a lack of treatments to address the linkage between stroke and PSD. This review summarizes the current knowledge of BDNF in PSD. By regulating BDNF expression, a synergistic effect may be achieved when such treatments are applied together with existing antidepressants.     

Cost-Effectiveness of Repetitive Transcranial Magnetic Stimulation versus Antidepressant Therapy for Treatment-Resistant Depression

BackgroundRepetitive transcranial magnetic stimulation (rTMS) therapy is a clinically safe, noninvasive, nonsystemic treatment for major depressive disorder.ObjectiveWe evaluated the cost-effectiveness of rTMS versus pharmacotherapy for the treatment of patients with major depressive disorder who have failed at least two adequate courses of antidepressant medications.MethodsA 3-year Markov microsimulation model with 2-monthly cycles was used to compare the costs and quality-adjusted life-years (QALYs) of rTMS and a mix of antidepressant medications (including selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, tricyclics, noradrenergic and specific serotonergic antidepressants, and monoamine oxidase inhibitors). The model synthesized data sourced from published literature, national cost reports, and expert opinions. Incremental cost-utility ratios were calculated, and uncertainty of the results was assessed using univariate and multivariate probabilistic sensitivity analyses.ResultsCompared with pharmacotherapy, rTMS is a dominant/cost-effective alternative for patients with treatment-resistant depressive disorder. The model predicted that QALYs gained with rTMS were higher than those gained with antidepressant medications (1.25 vs. 1.18 QALYs) while costs were slightly less (AU $31,003 vs. AU $31,190). In the Australian context, at the willingness-to-pay threshold of AU $50,000 per QALY gain, the probability that rTMS was cost-effective was 73%. Sensitivity analyses confirmed the superiority of rTMS in terms of value for money compared with antidepressant medications.ConclusionsAlthough both pharmacotherapy and rTMS are clinically effective treatments for major depressive disorder, rTMS is shown to outperform antidepressants in terms of cost-effectiveness for patients who have failed at least two adequate courses of antidepressant medications.     

Two Phase III randomised double-blind studies of fixed-dose TC-5214 (dexmecamylamine) adjunct to ongoing antidepressant therapy in patients with major depressive disorder and an inadequate response to prior antidepressant therapy

Objectives. To evaluate the neuronal nicotinic channel modulator TC-5214 (dexmecamylamine) as adjunct therapy in patients with major depressive disorder (MDD) and inadequate response to prior antidepressant treatment. Methods. Study 004 (D4130C00004) and Study 005 (D4130C00005) comprised an 8-week open-label antidepressant (SSRI/SNRI) treatment period followed by an 8-week randomised, active treatment with twice-daily TC-5214 (0.5, 2 or 4 mg in Study 004; 0.1, 1 or 4 mg in Study 005) or placebo, adjunct to ongoing SSRI/SNRI. Primary efficacy endpoint was change in MADRS total score from randomisation (Week 8) to treatment end (Week 16). Secondary endpoints included MADRS response and remission, and changes in SDS and HAM-D-17-item scores. Safety and tolerability were monitored throughout. Results. Studies 004 and 005 randomised 640 and 696 patients, respectively, to TC-5214 or placebo. No statistically significant improvements in MADRS total score or any secondary endpoints were seen with TC-5214 versus placebo in either study at treatment end. The most commonly reported adverse events (> 10%) with TC-5214 were constipation, dizziness and dry mouth. Conclusions. TC-5214 adjunct to antidepressant was generally well tolerated. However, the studies were not supportive of an antidepressant effect for TC-5214 in patients with MDD and inadequate response to prior antidepressant therapy.     

A Canadian Primary Care Sentinel Surveillance Network Study Evaluating Antidepressant Prescribing in Canada From 2006 to 2012

Objective:

To evaluate the prescribing patterns of antidepressants (ADs) by primary care providers to youth, adults, and seniors, from 2006 to 2012, using data from electronic medical records (EMRs).

Method:

This was a retrospective cross-sectional database study that used primary care data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN). Data on more than 600 000 Canadian primary care patients were used to determine the prevalence and incidence of AD prescribing to patients 15 years and older who had an encounter in the years of study (from 2006 to 2012). Each study year was evaluated independently.

Results:

The study population consisted of 86 927 patients in 2006 (mean age 48.1 years [SD 18.7], 38% male) and grew to 273 529 (mean age 49.6 years [SD 19.3], 40% male) in 2012. The prevalence of AD prescribing increased from 9.20% in 2006 to 12.80% in 2012 (P < 0.001). While the incidence rate of AD prescribing dropped from 3.54% in 2006 to 2.72% in 2008 (P < 0.001) the rate started to significantly rise again, reaching an incidence of 3.07% by 2012 (P < 0.001).

Conclusions:

The prevalence of AD prescribing by primary care providers in Canada continued to rise from 2006 to 2012. Conversely, incidence has remained stable or declined during the 6-year study period. While many complex factors likely contribute to the observed prevalence and incidence rates, our findings suggest that the guidelines indicating the efficacy of long-term AD therapy for patients with highly recurrent or severe depression are being followed.