Vilazodone Hydrochloride, a Combined SSRI and 5-HT1A Receptor Agonist for Major Depressive Disordersts

Novel spectrofluorometric approach for assessing vilazodone by blocking photoinduced electron transfer: analytical performance, and greenness-blueness evaluation

In this paper, vilazodone (VLD), a serotonin modulator prescribed for major depressive disorder, was investigated using a rapid, highly sensitive, and eco-friendly spectrofluorometric approach. The native fluorescence of VLD, originating from its indole moiety, exhibited an emission peak at 486 nm upon excitation at 241 nm. However, the presence of a piperazinyl nitrogen atom in the VLD structure, acting as an electron donor, significantly diminished the fluorescence intensity through photoinduced electron transfer (PET) to the indole ring. However, by protonating this nitrogen atom using 0.02 M Teorell-Stenhagen buffer (pH 3.5), inhibition of the PET process effectively blocked electron transfer, restoring the fluorescent properties of the drug. Further, an enhancement in the fluorescence was achieved by employing methanol as the solvent, resulting in a 1.5-fold increase. The combined use of PET blockage and methanol enabled the detection of VLD at levels as low as 0.78 ng mL-1. Calibration analysis demonstrated linearity within the range 5-400 ng mL-1, exhibiting a correlation coefficient of 0.9998 and a limit of quantification of 2.37 ng mL-1. The method obeyed the requirements of International Council on Harmonization (ICH). The proposed approach was applied for the accurate measurement of VLD in pharmaceutical tablets, content uniformity testing based on USP requirements, and determining VLD concentration in spiked human plasma. Moreover, the environmental impact, in addition to practical effectiveness, of the proposed approach was evaluated using different metrics.

Meta-analysis: Risk of dry mouth with second generation antidepressants

OBJECTIVE

The goal of this meta-analysis was to quantify the risk of dry mouth associated with commonly prescribed antidepressant agents and examine the potential implications of medication class, dose, and pharmacodynamics and dose on risk of treatment-induced dry mouth.

DATA SOURCES AND STUDY SELECTION

A PubMed search was conducted to identify double-blind, randomized, placebo-controlled trials examining the efficacy and tolerability of second generation antidepressant medications for adults with depressive disorders, anxiety disorders, and OCD.

DATA EXTRACTION

A random-effects meta-analysis was used to quantify the pooled risk ratio of treatment-emergent dry mouth with second generation antidepressants compared to placebo. Stratified subgroup analysis and meta-regression was utilized to further examine the effects antidepressant agent, class, dosage, indication, and receptor affinity profile on the measured risk of dry mouth.

RESULTS

99 trials involving 20,868 adults. SNRIs (Relative Risk (RR)=2.24, 95% Confidence Interval (CI): 1.95-2.58, z=11.2, p<0.001) were associated with a significantly greater risk of dry mouth (test for subgroup differences χ²=7.6, df=1; p=0.006) compared to placebo than SSRIs (RR=1.65, 95% CI: 1.39-1.95, z=5.8, p<0.001). There was a significant difference found in the risk of dry mouth between diagnostic indications within the SNRI class (test for subgroup differences χ²=9.63, df=1; p=0.002). Anxiety diagnoses (RR=2.78, 95% CI: 2.29-3.38, z=10.32, p<0.001) were associated with a greater risk of dry mouth compared to depression (RR=1.80, 95% CI: 1.48-2.18, z=5.85, p<0.001). Decreased affinity for Alpha-1 (PE=0.18, 95% CI: 0.07-0.28, z=3.26, p=0.001) and Alpha-2 (PE=0.49, 95% CI: 0.22-0.75, z=3.64, p<0.001) receptors and SERT (PE=0.07, 95% CI: 0.01-0.14, z=2.10, p<0.05) was significantly associated with increased risk of dry mouth.

CONCLUSIONS

The current meta-analysis suggests that SSRIs, SNRIs, and atypical antidepressants are all associated with varying degrees of increased risk of dry mouth. SNRIs were associated with a significantly greater risk of dry mouth compared to SSRIs.

The serotonergic system in the neurobiology of depression: Relevance for novel antidepressants

The monoamine hypothesis of depression posits that an imbalance in monoaminergic neurotransmission is causally related to the clinical features of depression. Antidepressants influencing serotonin mainly aim at raising serotonin concentrations, thereby increasing serotonergic transmission at the level of the synapse, for example by inhibiting the serotonin transporter. However, the serotonin system is multifaceted. Different serotonin receptor subtypes turn the serotonergic system into a complex neurochemical arrangement that influences diverse neurotransmitters in various brain regions. Classical antidepressants as well as other psychopharmacological agents have various crucial effects on serotonin receptors. We aim at providing a clinically useful characterization of serotonin receptor subtypes in the treatment of depression. Clarifying the mode of action and the interplay of serotonin receptors with pharmacological agents should help antidepressant mechanisms and typical side effects to be better understood. Against this background, we feature the novel antidepressants vortioxetine, vilazodone and milnacipran/levomilnacipran with regard to their serotonin receptor targets such as the 5-HT1A, 5-HT3 and 5-HT7 which may account for their specific effects on certain symptoms of depression (e.g. cognition and anxiety) as well as a characteristic side-effect profile.

Serotonergic modulation of glutamate neurotransmission as a strategy for treating depression and cognitive dysfunction

Monoamine-based treatments for depression have evolved greatly over the past several years, but shortcomings such as suboptimal efficacy, treatment lag, and residual cognitive dysfunction are still significant. Preclinical and clinical studies using compounds directly targeting glutamatergic neurotransmission present new opportunities for antidepressant treatment, with ketamine having a surprisingly rapid and sustained antidepressant effect that is presumably mediated through glutamate-dependent mechanisms. While direct modulation of glutamate transmission for antidepressant and cognition-enhancing actions may be hampered by nonspecific effects, indirect modulation through the serotonin (5-HT) system may be a viable alternative approach. Based on localization and function, 5-HT can modulate glutamate neurotransmission at least through the 5-HT1A, 5-HT1B, 5-HT3, and 5-HT7 receptors, which presents a rational pharmacological opportunity for modulating glutamatergic transmission without the direct use of glutamatergic compounds. Combining one or more of these glutamate-modulating 5-HT targets with 5-HT transporter inhibition may offer new therapeutic opportunities. The multimodal compounds vortioxetine and vilazodone are examples of this approach with diverse mechanisms, and their different clinical effects will provide valuable insights into serotonergic modulation of glutamate transmission for the potential treatment of depression and associated cognitive dysfunction.

Antidepressant-like activity of YL-0919: a novel combined selective serotonin reuptake inhibitor and 5-HT1A receptor agonist

It has been suggested that drugs combining activities of selective serotonin reuptake inhibitor and 5-HT1A receptor agonist may form a novel strategy for higher therapeutic efficacy of antidepressant. The present study aimed to examine the pharmacology of YL-0919, a novel synthetic compound with combined high affinity and selectivity for serotonin transporter and 5-HT1A receptors. We performed in vitro binding and function assays and in vivo behavioral tests to assess the pharmacological properties and antidepressant-like efficacy of YL-0919. YL-0919 displayed high affinity in vitro to both 5-HT1A receptor and 5-HT transporter prepared from rat cortical tissue. It exerted an inhibitory effect on forskolin-stimulated cAMP formation and potently inhibited 5-HT uptake in both rat cortical synaptosomes and recombinant cells. After acute p.o. administration, very low doses of YL-0919 reduced the immobility time in tail suspension test and forced swimming test in mice and rats, with no significant effect on locomotor activity in open field test. Furthermore, WAY-100635 (a selective 5-HT1A receptor antagonist, 0.3 mg/kg) significantly blocked the effect of YL-0919 in tail suspension test and forced swimming test. In addition, chronic YL-0919 treatment significantly reversed the depressive-like behaviors in chronically stressed rats. These findings suggest that YL-0919, a novel structure compound, exerts dual effect on the serotonergic system, as both 5-HT1A receptor agonist and 5-HT uptake blocker, showing remarkable antidepressant effects in animal models. Therefore, YL-0919 may be used as a new option for the treatment of major depressive disorder.