Serotonin syndrome: A pharmacovigilance comparative study of drugs affecting serotonin levels.

BACKGROUND: Serotonin syndrome is a rare and potentially fatal adverse drug reaction caused by serotonergic drugs and is due to an increase in serotonin concentration or activation of the 5-HT receptor in the central nervous system. We analysed adverse events in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) data set to investigate the main drug classes related to reports of serotonin syndrome and the reporting risk in relation to age and sex. METHODS: We analysed data from the FAERS database to evaluate the main drug classes related to reports of the serotonin syndrome, and the reporting risk in relation to age and sex. RESULTS: We found 8,997 cases of serotonin syndrome; selective serotonin reuptake inhibitors (SSRIs) was the class of drugs with most reports, followed by opioids and other antidepressants. The highest Reporting Odds Ratios (ROR) for drug classes was for monoamine oxidase (MAO) inhibitors (45.99, 95% confidence interval (CI): 41.21-51.33) and SSRIs (32.66, 95% CI: 31.33-34.04), while the ten active substances with the highest ROR were moclobemide, isocarboxazid, oxitriptane, tranylcypromine, melitracen, phenelzine, linezolid, amoxapine, reboxetine and tryptophan; with values of ROR ranging from 44.19 (95% CI: 25.38-76.94) of tryptophan to 388.36 (95% CI: 314.58-479.46) of moclobemide. The ROR for the most commonly involved drugs was higher in the group of older adults (65 > years old), and higher in males. CONCLUSION: Prescribers need to be vigilant about drugs that can raise serotonin concentration or influence serotonergic neurotransmission, also when using drugs with less well-known risk for serotonin syndrome, like linezolid and triptans.

Treatment-Resistant Depression (TRD): Is the Opioid System Involved?

About 30% of major depression disorder patients fail to achieve remission, hence being diagnosed with treatment-resistant major depression (TRD). Opium had been largely used effectively to treat depression for centuries, but when other medications were introduced, its use was discounted due to addiction and other hazards. In a series of previous studies, we evaluated the antinociceptive effects of eight antidepressant medications and their interaction with the opioid system. Mice were tested with a hotplate or tail-flick after being injected with different doses of mianserin, mirtazapine, trazodone, venlafaxine, reboxetine, moclobemide, fluoxetine, or fluvoxamine to determine the effect of each drug in eliciting antinociception. When naloxone inhibited the antinociceptive effect, we further examined the effect of the specific opioid antagonists of each antidepressant drug. Mianserin and mirtazapine (separately) induced dose-dependent antinociception, each one yielding a biphasic dose-response curve, and they were antagonized by naloxone. Trazodone and venlafaxine (separately) induced a dose-dependent antinociceptive effect, antagonized by naloxone. Reboxetine induced a weak antinociceptive effect with no significant opioid involvement, while moclobemide, fluoxetine, and fluvoxamine had no opioid-involved antinociceptive effects. Controlled clinical studies are needed to establish the efficacy of the augmentation of opiate antidepressants in persons with treatment-resistant depression and the optimal dosage of drugs prescribed.

Design, synthesis, and computational studies of phenylacetamides as antidepressant agents.

In the present work, a hit molecule obtained from zinc 'clean drug-like database' by systematically performed computational studies was modified chemically to obtain different derivatives (VS1-VS25). Structures of synthesized derivatives were confirmed by IR, 1H-NMR, 13C-NMR, 13C-DEPT, MS, and elemental analysis. All the synthesized compounds were biologically evaluated for their antidepressant activity by using tail suspension test and forced swimming test in albino mice. All these derivatives showed moderate to good antidepressant activity. The most potent compound (VS25) among the synthesized compounds showed better antidepressant potential than the standard drugs moclobemide, imipramine, and fluoxetine. To understand the time-dependent interactions of this most active compound with MAO-A molecular dynamics was carried out and reported here. Additionally, acute oral toxicity was performed for the most active compound as per OECD guidelines.

Monoamine oxidase inhibitors (MAOI): pharmacology, metabolism and application in the treatment of depression / Inhibitory monoaminooksydazy (IMAO): farmakologia, metabolizm i zastosowanie w terapii depresji o róznej etiologii.

The aim of this article is to synthesize informations about monoamine oxidase inhibitors drugs (MAOI) used in the treatment of depression. General informations on monoamine oxidase (MAO) and its kinetic properties are presented. MAO is an enzyme that degrades catecholamines and their 3-methoxy derivatives and other monoamines, for example serotonin or tryptamine. The criteria and symptoms of depressive disorders are discussed. They have to be distinguished from the state of sadness and similar states. The basic symptoms include: voice, facial expressions, anhedonia and psychomotor slowness. They may differ in individual diagnostic units. The following basic mechanism of the pharmacological action of MAOI has been indicated: when a drug inhibits MAO, the degradation of monoamines decreases and the concentration of the neurotransmitter in the synaptic cleft increases. Informations on selected selective and reversible MAOI-A are presented in the following sections. These are currently the safest and most effective MAOI drugs that can be used in the treatment of depressive diseases. The following drugs are discussed: moclobemide, befloxatone, toloxatone and brofaromine. Final conclusions are given and the presented data summarized.

Administration of moclobemide facilitates fear extinction and attenuates anxiety-like behaviors by regulating synaptic-associated proteins in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a long-lasting mental disorder and accompanied by worse fear extinction. Enhanced fear memory or poor fear extinction are typical features of PTSD. Dysfunction of the serotonergic neurotransmitter system is involved in numerous mental and behavioral disorders. Monoamine oxidase A (MAOA) is important in the metabolism of serotonin and play an important role in behavious. The aim of this study was to explore the change of MAOA and effect of MAOA on fear memory in PTSD. We used single prolonged stress (SPS) to create animal model of PTSD. A startle/fear box and elevated plus maze were used to observe fear memory and anxiety level, respectively. We examined the expression of MAOA and synaptic marker protein, as well as the immunological activity of MAOA in the infralimbic cortex (IL) area, which is a critical brain region involved in emotions, especially fear regulation. We found increased anxiety-like behavior, dysfunction in fear extinction, and increased MAOA in SPS rats. After treatment with moclobemide (a selective inhibitor of MAOA), SPS rats showed significantly improved fear memory and decreased anxiety-like behavior, which indicated that moclobemide could reverse fear extinction deficit and attenuate abnormally increased levels of anxiety caused by SPS in short term. On the contrary, decreased PSD-95 and SYN1 expression in the IL region were also reversed by moclobemide. These results suggest that increased MAOA play a negative role in fear extinction and levels of anxiety in PTSD, which may be involved in change in PSD-95 and SYN1.

Rhodium-Catalyzed Asymmetric Hydroamination of Allyl Amines.

A Rh-catalyzed enantioselective hydroamination of allylamines using a chiral BIPHEP-type ligand is reported. Enantioenriched 1,2-diamines are formed in good yields and with excellent enantioselectivities. A diverse array of nucleophiles and amine directing groups are demonstrated, including deprotectable motifs. Finally, the methodology was demonstrated toward the rapid synthesis of 2-methyl-moclobemide.

Bioavailability of moclobemide from two formulation tablets in healthy humans.

A ,,sine qua non" requirement for a generic formulation to be admitted for a medical use is to provide bioavailability studies in healthy subjects. Therefore, those studies were performed for 150 mg moclobemide tablets (Jelfa, Poland) versus 150 mg Aurorix (Hoffmann la Roche) reference tablets. An open-label, two-phase crossover study was conducted with 10 healthy subjects. Pharmacokinetic parameters (AUC, ke, t1/2, Cmax, tmax, tlag, V/f, Cl/f) obtained at the same time for moclobemide were supposed to be confronted with the literature data available for healthy volunteers. The plasma moclobemide levels as a function of time were calculated according to either an open one-compartment body model with lag time of absorption or non-compartmental method for calculation of bioavailability using Phoenix WinNonlin 8.0 software. For those reasons a suitable HPLC method was worked out. Carbamazepine was proposed as an internal standard and ammonia as well as Na2HPO4 as alkalizing agents for the mobile phase and the liquid-liquid extraction of moclobemide from human blood plasma, respectively. Basic pharmacokinetic parameters of moclobemide obtained in the paper are essentially equal to the literature data for the healthy subjects. However, bioavailability parameters (AUC0→t, AUC0→∞, Cmax, tmax) were greater for moclobemide tablets (Jelfa) if compared to Aurorix tablets (Roche) by more than 20 %. Furthermore, the extent of bioavailability (110.6 %) for the generic moclobemide tablets if compared to Aurorix tablets is not significantly different. It seems to us that the number of subjects should be increased from 10 to 24 to help to clarify that inconsequence.

Resting regional brain metabolism in social anxiety disorder and the effect of moclobemide therapy.

While there is mounting evidence of abnormal reactivity of several brain regions in social anxiety disorder, and disrupted functional connectivity between these regions at rest, relatively little is known regarding resting regional neural activity in these structures, or how such activity is affected by pharmacotherapy. Using 2-deoxy-2-(F-18)fluoro-D-glucose positron emission tomography, we compared resting regional brain metabolism between SAD and healthy control groups; and in SAD participants before and after moclobemide therapy. Voxel-based analyses were confined to a predefined search volume. A second, exploratory whole-brain analysis was conducted using a more liberal statistical threshold. Fifteen SAD participants and fifteen matched controls were included in the group comparison. A subgroup of SAD participants (n = 11) was included in the therapy effect comparison. No significant clusters were identified in the primary analysis. In the exploratory analysis, the SAD group exhibited increased metabolism in left fusiform gyrus and right temporal pole. After therapy, SAD participants exhibited reductions in regional metabolism in a medial dorsal prefrontal region and increases in right caudate, right insula and left postcentral gyrus. This study adds to the limited existing work on resting regional brain activity in SAD and the effects of therapy. The negative results of our primary analysis suggest that resting regional activity differences in the disorder, and moclobemide effects on regional metabolism, if present, are small. While the outcomes of our secondary analysis should be interpreted with caution, they may contribute to formulating future hypotheses or in pooled analyses.

One-Pot Amide Bond Formation from Aldehydes and Amines via a Photoorganocatalytic Activation of Aldehydes.

A mild, one-pot, and environmentally friendly synthesis of amides from aldehydes and amines is described. Initially, a photoorganocatalytic reaction of aldehydes with di-isopropyl azodicarboxylate leads to an intermediate carbonyl imide, which can react with a variety of amines to afford the desired amides. The initial visible light-mediated activation of a variety of monosubstituted or disubstituted aldehydes is usually fast, occurring in a few hours. Following the photocatalytic reaction, addition of the primary amine at room temperature or the secondary amine at elevated temperatures leads to the corresponding amide from moderate to excellent yields without epimerization. This methodology was applied in the synthesis of Moclobemide, a drug against depression and social anxiety.

Column Selection for Biomedical Analysis Supported by Column Classification Based on Four Test Parameters.

This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis.

Monoamine Oxidase-A Occupancy by Moclobemide and Phenelzine: Implications for the Development of Monoamine Oxidase Inhibitors.

BACKGROUND: Monoamine oxidase inhibitors (MAOIs) are being developed for major depressive disorder, Alzheimer's, and Parkinson's Disease. Newer MAOIs have minimal sensitivity to tyramine, but a key limitation for optimizing their development is that standards for in vivo monoamine oxidase-A (MAO-A) occupancy in humans are not well established. The objectives were to determine the dose-occupancy relationship of moclobemide and the occupancy of phenelzine at typical clinical dosing. METHODS: Major depressive episode (MDE) subjects underwent [(11)C]harmine positron emission tomography scanning prior to and following 6 weeks of treatment with moclobemide or phenelzine. RESULTS: Mean brain MAO-A occupancies were 74.23±8.32% for moclobemide at 300-600 mg daily (n = 11), 83.75±5.52% for moclobemide at 900-1200 mg daily (n = 9), and 86.82±6.89% for phenelzine at 45-60 mg daily (n = 4). The regional dose-occupancy relationship of moclobemide fit a hyperbolic function [F(x) = a(x/[b + x]); F(1,18) = 5.57 to 13.32, p = 0.002 to 0.03, mean 'a': 88.62±2.38%, mean 'b': 69.88±4.36 mg]. Multivariate analyses of variance showed significantly greater occupancy of phenelzine (45-60mg) and higher-dose moclobemide (900-1200 mg) compared to lower-dose moclobemide [300-600 mg; F(7,16) = 3.94, p = 0.01]. CONCLUSIONS: These findings suggest that for first-line MDE treatment, daily moclobemide doses of 300-600mg correspond to a MAO-A occupancy of 74%, whereas for treatment-resistant MDE, either phenelzine or higher doses of moclobemide correspond to a MAO-A occupancy of at least 84%. Therefore, novel MAO inhibitor development should aim for similar thresholds. The findings provide a rationale in treatment algorithm design to raise moclobemide doses to inhibit more MAO-A sites, but suggest switching from high-dose moclobemide to phenelzine is best justified by binding to additional targets.

Design, synthesis, and biological evaluation of oxindole derivatives as antidepressive agents.

The 3-substituted oxindole derivatives were designed, synthesized, and evaluated for antidepressant activity by employing forced swimming test, tail suspension test, and MAO-A inhibition assay. Results of biological studies revealed that the majority of compounds exhibited potent to moderately potent activity and among them, 12 displayed potency comparable to that of the imipramine with %DID of 37.95 and 44.84 in the FST and TST, respectively. At the same time, imipramine showed %DID of 43.62 and 50.64 in the FST and TST, correspondingly. In the MAO-A inhibition assay, 12 showed an IC50 of 18.27 µmol, whereas the reference drug moclobemide displayed an IC50 of 13.1 µmol. The SAR study disclosed that the presence of bromo atom at the phenyl/furanyl or thienyl moiety in the oxindole derivatives was critical for the antidepressant activity.

Antidepressant-like effects of ferulic acid: involvement of serotonergic and norepinergic systems.

Ferulic acid is a polyphenol that has antioxidant, anti-inflammatory and anticancer properties. The present study analyzed the antidepressant-like potential of ferulic acid using two well-validated mouse models of despair test, tail suspension and forced swim tests. The results suggested that ferulic acid treatment at doses of 10, 20, 40 and 80 mg/kg (p.o.) significantly reduced the immobility time in both of these two tests. These doses that affected the depressive-like behaviors did now show any effect on locomotion counts. The further neurochemical assays suggested that ferulic acid increased monoamine neurotransmitter levels in the brain regions that are relative to mood disorders: the hippocampus and frontal cortex. The increased tend to serotonin and norepinephrine was also found in the hypothalamus after higher dose of ferulic acid treatment. The subsequent study suggested that monoamine oxidase A (MAO-A) activity was inhibited in the frontal cortex and hippocampus when treatment with 40 and 80 mg/kg ferulic acid; while MAO-B activity did not change significantly. The current study provides the first lines of evidence that serotonin and norepinephrine, but not dopamine levels were elevated in mouse hippocampus and frontal cortex after ferulic acid treatment. These changes may be attributable to the inhibition of MAO-A activities in the same brain regions.

Synthesis and Screening of Human Monoamine Oxidase-A Inhibitor Effect of New 2-Pyrazoline and Hydrazone Derivatives.

A group of 3,5-diaryl-2-pyrazoline and hydrazone derivatives was prepared via the reaction of various chalcones with hydrazide compounds in ethanol. Twenty original compounds were synthesized. Ten of these original compounds have a pyrazoline structure, nine of these original compounds have a hydrazone structure, and one of these original compounds has a chalcone structure. Structural elucidation of the compounds was performed by IR, (1)H NMR, (13)C NMR, mass spectral data, and elemental analyses. These compounds were tested for their inhibitory activities toward the A and B isoforms of human monoamine oxidase (MAO). Except for 3k and 6c, all compounds were found to be competitive, reversible, and selective inhibitors for either one of the isoforms (hMAO-A or MAO-B). Compounds 3k and 6c were found to be competitive, reversible, but non-selective MAO inhibitors. Compound 6h showed hMAO-B inhibitory activity whereas the others potently inhibited hMAO-A. Compound 5c showed higher selectivity than the standard drug moclobemide. According to the experimental K(i) values, compounds 6i, 6d, and 6a exhibited the highest inhibitory activity toward hMAO-A. The AutoDock 4.2 program was employed to perform automated molecular docking. The calculated results obtained computationally were in good agreement with the experimental values.

Effect of dichloromethane fraction of Areca catechu nut on monoamines associated behaviors and tyramine pressor sensitivity in rodents.

The current study was aimed at investigating the effect of Areca catechu nut dichloromethane fraction (7 mg/kg) on monoamines (serotonin and dopamine) modulation (5-hydroxytryptophan-induced tremors and phenylethylamine-induced stereotypes) and its interaction with tyramine (cheese effect). The dichloromethane fraction caused pronounced increase in 5-HTP-induced tremors (50%) with negligible PEA-induced stereotypes (20%). Additionally, it did not produce a significant increase in the tyramine pressor effects. These results suggest that the dichloromethane fraction of A. catechu nut primarily elevates serotonin levels (probably via monoamine oxidase A inhibition) and does not induce cheese effect.

Identification of the exosomal PD-L1 inhibitor to promote the PD-1 targeting therapy of gastric cancer.

Programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) targeting therapy is widely applied in clinics for gastric cancer treatment. Nevertheless, the clinical response is not well acceptable due to the exosomal PD-L1. Hence, abrogation of the exosomal PD-L1 may be a strategy to sensitize the gastric cancer cell to PD-1 targeting therapy. With the aid of CD63 targeting antibody and PD-L1 targeting aptamer, HTRF based assay was established to quantify the exosomal PD-L1, and applied to our in-house compound library, resulting in the identification of moclobemide. Further optimization of moclobemide lead to EP16, which can inhibit the generation of exosomal PD-L1 with IC50 = 0.108 µM. By applying EP16 to gastric cancer cell line coupled with T-cell activity related experiment, it was validated to activate T-cell and can promote the response of PD-1 targeting therapy for gastric cancer treatment in vitro and in vivo. Collectively, our findings give a promising tool to promote the sensitivity of anti-PD-1 for gastric cancer treatment, and EP16 can serve as a leading compound for exosomal PD-L1 abrogation.

Validated UPLC-MS/MS method for determination of moclobemide in human brain cell supernatant and its application to bidirectional transport study.

A simple and sensitive analytical method based on ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed for determination of moclobemide in human brain cell monolayer as an in vitro model of blood-brain barrier. Brucine was employed as the internal standard. Moclobemide and internal standard were extracted from cell supernatant by ethyl acetate after alkalinizing with sodium hydroxide. The UPLC separation was performed on an Acquity UPLC(TM) BEH C18 column (50 × 2.1 mm, 1.7 µm, Waters, USA) with a mobile phase consisting of methanol-water (29.5:70.5, v/v); the water in the mobile phase contained 0.05% ammonium acetate and 0.1% formic acid. Detection of the analytes was achieved using positive ion electrospray via multiple reaction monitoring mode. The mass transitions were m/z 269.16 → 182.01 for moclobemide and m/z 395.24 → 324.15 for brucine. The extraction recovery was 83.0-83.4% and the lower limit of quantitation (LLOQ) was 1.0 ng/mL for moclobemide. The method was validated from LLOQ to 1980 ng/mL with a coefficient of determination greater than 0.999. Intra- and inter-day accuracies of the method at three concentrations ranged from 89.1 to 100.9% for moclobemide with precision of 1.1-9.6%. This validated method was successfully applied to bidirectional transport study of moclobemide blood-brain barrier permeability.

Amidation by reactive extrusion for the synthesis of active pharmaceutical ingredients teriflunomide and moclobemide.

The solventless synthesis of an amide was performed in a twin-screw extruder in the presence of a coupling agent, providing a high yielding and productive method. The reaction conditions were optimized to prepare APIs, teriflunomide and moclobemide.