Tranylcypromine in mind (Part II): Review of clinical pharmacology and meta-analysis of controlled studies in depression

Plasma Concentrations of Tranylcypromine in Depressed Patients With Chronic Kidney Disease: Two Case Reports

PURPOSE

The prevalence of comorbid depression and chronic kidney disease (CKD) is high. The aim of this brief report was to review 2 cases of treatment with tranylcypromine (TCP) in patients with treatment-resistant depression (TRD) and CKD. Tests of the plasma concentration of TCP were included.

METHODS

Medical and psychiatric notes of the 2 patients were reviewed with plasma concentrations of TCP as a key aspect of the discussion. The data are evaluated in the context of relevant medical and pharmacokinetic literature.

FINDINGS

Plasma concentrations of TCP are highly variable both in patients with and without CKD. Plasma concentrations of TCP were not increased in the 2 cases with CKD as compared with literature data of patients without CKD. No signs of intoxication were detected in 2 cases with CKD that impaired continuous treatment of depression with TCP.

IMPLICATIONS

TCP may be considered in selected cases of TRD with concomitant CKD. More clinical data and tests of plasma concentrations of TCP are needed in patients with CKD.

Lysine demethylase LSD1 is associated with stemness in EBV-positive B cell lymphoma

EBV-infected lymphoma has a poor prognosis and various treatment strategies are being explored. Reports suggesting that B cell lymphoma can be induced by epigenetic regulation have piqued interest in studying mechanisms targeting epigenetic regulation. Here, we set out to identify an epigenetic regulator drug that acts synergistically with doxorubicin in EBV-positive lymphoma. We expressed the major EBV protein, LMP1, in B-cell lymphoma cell lines and used them to screen 100 epigenetic modifiers in combination with doxorubicin. The screening results identified TCP, which is an inhibitor of LSD1. Further analyses revealed that LMP1 increased the activity of LSD1 to enhance stemness ability under doxorubicin treatment, as evidenced by colony-forming and ALDEFLUOR activity assays. Quantseq 3' mRNA sequencing analysis of potential targets regulated by LSD1 in modulating stemness revealed that the LMP1-induced upregulation of CHAC2 was decreased when LSD1 was inhibited by TCP or downregulated by siRNA. We further observed that SOX2 expression was altered in response to CHAC2 expression, suggesting that stemness is regulated. Collectively, these findings suggest that LSD1 inhibitors could serve as promising therapeutic candidates for EBV-positive lymphoma, potentially reducing stemness activity when combined with conventional drugs to offer an effective treatment approach.

Synergistic Effects of Tranylcypromine and NRF2 Inhibitor: A Repurposing Strategy for Effective Cancer Therapy

Drug repurposing has emerged as an attractive strategy for accelerating drug discovery for cancer treatment. In this study, we investigated combining Tranylcypromine (TCP) with a number of well-characterized drugs. Among these combinations, NRF2 inhibitor (ML385) exhibited synergistic effects in combination with TCP. Specifically, our results showed that the combination of TCP and ML385 resulted in a significant reduction in tumor proliferation while neither drug affected cancer cell growth meaningfully on its own. While further studies are needed to understand fully the extent of the synergistic efficacy, the underlying respective mechanisms and the potential side effects of this approach, our study has yielded a promising start for the development of an effective combination cancer therapy.

[Psychopharmacotherapy with the MAO-inhibitor Tranylcypromine Key Aspects and Trends in Theory and Practice]

The irreversible monoamine oxidase inhibitor tranylcypromine has been known as an antidepressant drug for more than 60 years. The aim of this review was to make an assessment of the state of the art and therapy of tranylcypromine. The recent medical-scientific literature is analyzed and discussed with respect to key aspects of and general trends in practical psychopharmacotherapy. Meta-analyses of controlled clinical studies have shown that tranylcypromine is an established approach to treatment-resistant depression. Doses (maximum dose, maintenance dose) are increasingly adapted to the requirements of treatment-resistant depression. Monoamine oxidase is not only the primary pharmacological target of tranylcypromine but determines for the first doses also the pharmacokinetics of tranylcypromine because monoamine oxidase is also an enantioselective drug-metabolizing enzyme of the monoamine oxidase inhibitor. An increased diversity of the antidepressant pharmacotherapy suggests the need to rethink the continuing assessment of tranylcypromine as a therapeutic "ultima ratio" in depression. In conclusion, tranylcypromine as a drug of second choice remains a valuable option in antidepressant treatment. Criteria of a switch from other antidepressant drugs to tranylcypromine should be better defined.

In Vitro Human Monoamine Oxidase Inhibition and Human Dopamine D4 Receptor Antagonist Effect of Natural Flavonoids for Neuroprotection

Natural flavone and isoflavone analogs such as 3',4',7-trihydroxyflavone (1), 3',4',7-trihydroxyisoflavone (2), and calycosin (3) possess significant neuroprotective activity in Alzheimer's and Parkinson's disease. This study highlights the in vitro human monoamine oxidase (hMAO) inhibitory potential and functional effect of those natural flavonoids at dopamine and serotonin receptors for their possible role in neuroprotection. In vitro hMAO inhibition and enzyme kinetics studies were performed using a chemiluminescent assay. The functional effect of three natural flavonoids on dopamine and serotonin receptors was tested via cell-based functional assays followed by a molecular docking simulation to predict interactions between a compound and the binding site of the target protein. A forced swimming test was performed in the male C57BL/6 mouse model. Results of in vitro chemiluminescent assays and enzyme kinetics depicted 1 as a competitive inhibitor of hMAO-A with promising potency (IC50 value: 7.57 ± 0.14 μM) and 3 as a competitive inhibitor of hMAO-B with an IC50 value of 7.19 ± 0.32 μM. Likewise, GPCR functional assays in transfected cells showed 1 as a good hD4R antagonist. In docking analysis, these active flavonoids interacted with a determinant-interacting residue via hydrophilic and hydrophobic interactions, with low docking scores comparable to reference ligands. The post-oral administration of 1 to male C57BL/6 mice did not reduce the immobility time in the forced swimming test. The results of this study suggest that 1 and 3 may serve as effective regulators of the aminergic system via hMAO inhibition and the hD4R antagonist effect, respectively, for neuroprotection. The route of administration should be considered.

Potential efficacy of dopaminergic antidepressants in treatment resistant anergic-anhedonic depression results of the chronic anergic-anhedonic depression open trial - CADOT

Introduction

Among treatment-resistant depression (TRD), we identified anergic-anhedonic clinical presentations (TRAD) as putatively responsive to pro-dopaminergic strategies. Based on the literature, non-selective monoamine oxidase inhibitors (MAOI) and dopamine D2 receptor agonists (D2RAG) were sequentially introduced, frequently under the coverage of a mood stabilizer. This two-step therapeutic strategy will be referred to as the Dopaminergic Antidepressant Therapy Algorithm (DATA). We describe the short and long-term outcomes of TRAD managed according to DATA guidelines.

Method

Out of 52 outpatients with TRAD treated with DATA in a single expert center, 48 were included in the analysis [severity - QIDS (Quick Inventory of Depressive Symptomatology) = 16 ± 3; episode duration = 4.1 ± 2.7 years; Thase and Rush resistance stage = 2.9 ± 0.6; functioning - GAF (Global Assessment of Functioning) = 41 ± 8]. These were followed-up for a median (1st - 3rd quartile) of 4 (1-9) months before being prescribed the first dopaminergic treatment and remitters were followed up 21 (11-33) months after remission.

Results

At the end of DATA step 1, 25 patients were in remission (QIDS <6; 52% [38-66%]). After DATA step 2, 37 patients were in remission (77% [65-89%]) to whom 5 patients with a QIDS score = 6 could be added (88% [78-97%]). Many of these patients felt subjectively remitted (GAF = 74 ± 10). There was a significant benefit to combining MAOI with D2RAG which was maintained for at least 18 months in 30 patients (79% [62-95%]).

Conclusion

These results support TRAD sensitivity to pro-dopaminergic interventions. However, some clinical heterogeneities remain in our sample and suggest some improvement in the description of dopamine-sensitive form(s).

Therapy Strategies for Late-life Depression: A Review

BACKGROUND

Depression in the elderly requires different treatment options because therapies that are commonly used for depression in younger patients show different effects later in life. Treatment options for late-life depression (LLD) are summarized in this article.

METHODS

A literature search in Medline/PubMed performed in June 2020 identified 83 relevant studies.

RESULTS

Pharmacotherapy with selective serotonin reuptake inhibitors can be an effective first-line treatment in LLD, but >50% of elderly patients do not adequately respond. Switching to other selective serotonin reuptake inhibitors or augmenting with mood stabilizers or antipsychotics is often effective in achieving a therapeutic benefit. Severely depressed patients with a high risk of suicidal behavior can be treated with electroconvulsive therapy. Psychotherapy provides a measurable benefit alone and when combined with medication.

LIMITATIONS

LLD remains an underrepresented domain in research. Paucity of data concerning the effect of specific therapies for LLD, heterogeneity in the quality of study designs, overinterpretation of results from meta-analyses, and discrepancies between study results and guideline recommendations were often noted.

CONCLUSIONS

Treating LLD is complex, but there are several treatment options with good efficacy and tolerability. Some novel pharmaceuticals also show promise as potential antidepressants, but evidence for their efficacy and safety is still limited and based on only a few trials conducted to date.

Biomarker-driven drug repurposing on biologically similar cancers with DNA-repair deficiencies

Similar molecular and genetic aberrations among diseases can lead to the discovery of jointly important treatment options across biologically similar diseases. Oncologists closely looked at several hormone-dependent cancers and identified remarkable pathological and molecular similarities in their DNA repair pathway abnormalities. Although deficiencies in Homologous Recombination (HR) pathway plays a significant role towards cancer progression, there could be other DNA-repair pathway deficiencies that requires careful investigation. In this paper, through a biomarker-driven drug repurposing model, we identified several potential drug candidates for breast and prostate cancer patients with DNA-repair deficiencies based on common specific biomarkers and irrespective of the organ the tumors originated from. Normalized discounted cumulative gain (NDCG) and sensitivity analysis were used to assess the performance of the drug repurposing model. Our results showed that Mitoxantrone and Genistein were among drugs with high therapeutic effects that significantly reverted the gene expression changes caused by the disease (FDR adjusted p-values for prostate cancer =1.225e-4 and 8.195e-8, respectively) for patients with deficiencies in their homologous recombination (HR) pathways. The proposed multi-cancer treatment framework, suitable for patients whose cancers had common specific biomarkers, has the potential to identify promising drug candidates by enriching the study population through the integration of multiple cancers and targeting patients who respond poorly to organ-specific treatments.

Evolution of ideas about the risk of tyramine syndrome developing during therapy with irreversible non-selective monoamine oxidase inhibitors (to the 70th anniversary of the first use of this group of antidepressants)

We describe the history of studying of the problem of tyramine syndrome during the treatment with antidepressants, irreversible non-selective monoamine oxidase inhibitors. Data on clinical observations are presented. Early hypotheses of pathogenesis are considered. The period of discovery of the relationship between increased blood pressure and the use of foods containing tyramine is outlined. The transformation of terminology is demonstrated. The events associated with the restriction of the use of therapy are characterized. The formation of the opinion about the exaggeration of the risk of developing tyramine syndrome is analyzed. Data on the involvement in the discussion of the problem of tyramine syndrome of society as a whole are given. 

The prescriber's guide to classic MAO inhibitors (phenelzine, tranylcypromine, isocarboxazid) for treatment-resistant depression

This article is a clinical guide which discusses the "state-of-the-art" usage of the classic monoamine oxidase inhibitor (MAOI) antidepressants (phenelzine, tranylcypromine, and isocarboxazid) in modern psychiatric practice. The guide is for all clinicians, including those who may not be experienced MAOI prescribers. It discusses indications, drug-drug interactions, side-effect management, and the safety of various augmentation strategies. There is a clear and broad consensus (more than 70 international expert endorsers), based on 6 decades of experience, for the recommendations herein exposited. They are based on empirical evidence and expert opinion-this guide is presented as a new specialist-consensus standard. The guide provides practical clinical advice, and is the basis for the rational use of these drugs, particularly because it improves and updates knowledge, and corrects the various misconceptions that have hitherto been prominent in the literature, partly due to insufficient knowledge of pharmacology. The guide suggests that MAOIs should always be considered in cases of treatment-resistant depression (including those melancholic in nature), and prior to electroconvulsive therapy-while taking into account of patient preference. In selected cases, they may be considered earlier in the treatment algorithm than has previously been customary, and should not be regarded as drugs of last resort; they may prove decisively effective when many other treatments have failed. The guide clarifies key points on the concomitant use of incorrectly proscribed drugs such as methylphenidate and some tricyclic antidepressants. It also illustrates the straightforward "bridging" methods that may be used to transition simply and safely from other antidepressants to MAOIs.

Monoamine Oxidase Inhibition by Plant-Derived β-Carbolines; Implications for the Psychopharmacology of Tobacco and Ayahuasca

The monoamine oxidases (MAOs) are flavin-containing amine oxidoreductases responsible for metabolism of many biogenic amine molecules in the brain and peripheral tissues. Whereas serotonin is the preferred substrate of MAO-A, phenylethylamine is metabolized by MAO-B, and dopamine and tyramine are nearly ambivalent with respect to the two isozymes. β-Carboline alkaloids such as harmine, harman(e), and norharman(e) are MAO inhibitors present in many plant materials, including foodstuffs, medicinal plants, and intoxicants, notably in tobacco (Nicotiana spp.) and in Banisteriopsis caapi, a vine used in the Amazonian ayahuasca brew. The β-carbolines present in B. caapi may have effects on neurogenesis and intrinsic antidepressant properties, in addition to potentiating the bioavailability of the hallucinogen N,N-dimethyltryptamine (DMT), which is often present in admixture plants of ayahuasca such as Psychotria viridis. Tobacco also contains physiologically relevant concentrations of β-carbolines, which potentially contribute to its psychopharmacology. However, in both cases, the threshold of MAO inhibition sufficient to interact with biogenic amine neurotransmission remains to be established. An important class of antidepressant medications provoke a complete and irreversible inhibition of MAO-A/B, and such complete inhibition is almost unattainable with reversible and competitive inhibitors such as β-carbolines. However, the preclinical and clinical observations with synthetic MAO inhibitors present a background for obtaining a better understanding of the polypharmacologies of tobacco and ayahuasca. Furthermore, MAO inhibitors of diverse structures are present in a wide variety of medicinal plants, but their pharmacological relevance in many instances remains to be established.

60 Years of Combining Tranylcypromine: A Systematic Review of Available Evidence

BACKGROUND

Tranylcypromine is the only irreversible monoamine oxidase inhibitor that is approved in the United States and in Europe for the management of treatment-resistant major depressive disorder. Comprehensive data in the literature regarding the efficacy and tolerability of tranylcypromine (TCP) combination strategies have not been systematically investigated yet.

METHODS

We conducted a systematic review of available literature based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Study types considered eligible for inclusion were studies that reported information on efficacy and/or tolerability/adverse effects of pharmacological TCP add-on or coadministration strategies among people with psychiatric disorders.

RESULTS

Ninety-six articles were included in qualitative analyses. A relevant body of evidence shows that TCP combined with first- and second-generation antipsychotics seems relatively safe and might have beneficial effects in some patients with depressive disorders, although caution is needed with some second-generation antipsychotics that have proserotonergic activity. Although evidence is not entirely consistent, amitriptyline as add-on agent might be efficacious and associated with a low rate of severe adverse events. Although available data from case reports are scarce, certain other agents, such as trazodone, but also lithium, seem to have a good risk-benefit profile with regard to TCP that should be further investigated in the context of high-quality studies.

CONCLUSIONS

Any combination of a psychotropic with TCP should be preceded by an evaluation of drug-to-drug interaction and an informed consent process and followed by close monitoring. Before any combination strategy, doctors should reevaluate factors of pseudo-treatment resistance, such as rapid-metabolizing status, noncompliance, trauma, alternative diagnosis, or drug abuse.

Faster speed of onset of the depressive episode is associated with lower cytokine serum levels (IL-2, -4, -6, -10, TNF-α and IFN-γ) in patients with major depression

INTRODUCTION

Cytokines might play a key role in the pathophysiology of major depressive disorder (MDD). The speed of onset of depressive episodes has been discussed as an important clinical parameter in MDD. The aim of this study was to investigate a potential influence of the speed of onset of the depressive episode on cytokine serum levels.

METHOD

Serum level of the cytokines interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ) granulocyte and monocyte colony stimulating factor (GM-CSF) were measured in a total of 92 patients with MDD that did not respond to at least one previous antidepressant treatment. Patients were retrospectively divided in two groups: Faster (≤4 weeks) and slower (>4 weeks) onset of the depressive episode defined as the time passing from the first depressive symptoms to a full-blown depressive episode by using information from a clinical interview.

RESULTS

We found significantly lower serum levels of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ in patients with a faster onset compared to patients with a slower onset of the depressive episodes. Furthermore, lower cytokine serum levels of IL-2, IL-8, IL-10 and IFN-γ were found in patients with a shorter duration (less than 6 months) compared to a longer duration (6-24 months) of the current depressive episode. This effect on cytokines was independent from the effect of the speed of onset of the depressive episode.

CONCLUSIONS

Patients with faster onset of the depressive episode might represent a biological subtype of MDD with lower serum levels of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ.

The trace amine theory of spontaneous hypertension as induced by classic monoamine oxidase inhibitors

The classic monoamine oxidase inhibitors (MAOIs) tranylcypromine (TCP) and phenelzine (PLZ) are powerful antidepressants that come with an equally powerful stigma, and are thus rarely prescribed-despite their well-established effectiveness. Some of these preconceptions appear to stem from unclarity, as the etiology of a rare but important side effect, 'spontaneous hypertension' (SH)-a significant increase in blood pressure absent dietary tyramine ingestion-remains improperly elucidated. This paper aims at uprooting some of the stigma surrounding MAOIs by advancing the trace amine (TA) theory as the causative underpinning of SH. This theory posits that SH results from the considerable influx of TAs observed following TCP- or PLZ-administration. TAs are known, albeit at greatly supraphysiological levels, to raise blood pressure on account of their propensity to exert potent indirect sympathomimetic effects; additionally, some research posits that TAs may induce vasoconstrictive effects partly or wholly separate therefrom, which would then constitute a second hypertensive mechanism. TAs are endogenous to the human body in low quantities. Both TCP and PLZ cause marked elevations of 2-phenylethylamine (PEA), meta- and para-tyramine (m-/p-TYR), octopamine (OA), and tryptamine (TRYP), following both acute and (sub)chronic administration. This paper holds that TYR plays a pivotal role in causing SH, due to its strong pressor effect. Cautious treatment of SH is advised, given its typically self-limiting nature. The risk of hypotensive overshoots must be taken into account. For severe cases, this paper urges reconsideration, following suitable confirmation trials, of antipsychotics (notably risperidone) as these agents may reduce striatal p-TYR levels.

Insights into the Mechanism of the Therapeutic Potential of Herbal Monoamine Oxidase Inhibitors in Neurological Diseases

Monoamine oxidase (MAO) is an enzyme that catalyzes the deamination of monoamines and other proteins. MAO's hyperactivation results in the massive generation of reactive oxygen species, which leads to a variety of neurological diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and depression-like disorders. Although synthetic MAO inhibitors are clinically available, they are associated with side effects such as hepatotoxicity, cheese reaction, hypertensive crisis, and so on, necessitating the investigation of alternative MAO inhibitors from a natural source with a safe profile. Herbal medications have a significant impact on the prevention of many diseases; additionally, they have fewer side effects and serve as a precursor for drug development. This review discusses the potential of herbal MAO inhibitors as well as their associated mechanism of action, with an aim to foster future research on herbal MAO inhibitors as potential treatment for neurological diseases.

Monoamine Oxidase Inhibitors (MAOIs) in Psychiatric Practice: How to Use them Safely and Effectively

Monoamine oxidase inhibitors (MAOIs) were among the first licensed pharmacological treatments for patients with depression but over time have fallen out of mainstream clinical use. This has led to a loss of clinician training opportunities and reduced availability of MAOIs for prescribing. This article provides a concise and practical overview of how to use MAOIs safely and effectively in psychiatric practice. We consider the history of MAOIs, why they are not used more frequently, their mechanisms of action, availability, indications and efficacy, general tolerability, withdrawal symptoms, and safety considerations (including hypertensive reactions and serotonin syndrome). Practical advice is given in terms of dietary restrictions, interactions with other medications (both prescribed and non-prescribed), and how prescribers can stop and switch MAOIs, both within the drug class and outside of it. We also provide advice on choice of MAOI and treatment sequencing. Lastly, we consider emerging directions and potential additional indications.

Review and meta-analysis of add-on tranylcypromine with antipsychotic drugs for the treatment of schizophrenia with predominant negative symptoms: a restoration of evidence

BACKGROUND

Treatment using add-on antidepressants with antipsychotic drugs in negative symptoms of schizophrenia has been reviewed recently in comprehensive meta-analyses. Tranylcypromine (TCP), an irreversible monoamine oxidase (MAO)-A/B inhibitor applied in treatment resistant depression, was not included because of strict requirements for quality of study design. To get a clear picture of available evidence for this resource in the treatment of schizophrenia, we conducted a review and meta-analysis of add-on TCP in the treatment of predominant negative symptoms of schizophrenia (negative schizophrenia).

METHODS

Seven controlled studies of add-on TCP in schizophrenia with predominant negative symptoms were found in a search of multiple databases. A subset of four studies of the prospective and parallel comparison of add-on TCP with antipsychotic drugs vs. antipsychotic drug monotherapy and meeting minimum quality criteria formed the primary meta-analysis. The effect size was calculated as the natural logarithm of the odds ratio (logOR) of responders and non-responders.

RESULTS

In the primary meta-analysis, a pooled logOR = 1.092 with 95%CI 0.410-1.774 (I² = 43.4%, moderate heterogeneity) was calculated according to a fixed-effect model. Heterogeneity was reduced for three double-blind studies of add-on TCP with trifluoperazine (TFP) vs. TFP-monotherapy and resulted a pooled logOR = 0.916 with 95%CI 0.216-1.616 (I² negative, no heterogeneity). A significant logOR = 1.558 with 95%CI 0.340-2.776 was found for TCP/TFP compared to placebo in one study. In a meta-analysis of extrapyramidal adverse effects, studies were very heterogeneous and revealed no significant differences between treatments. The risk of exacerbation of positive symptoms with add-on TCP was found to be very low for a duration of treatment of 12-16 weeks. No cases of hypertensive crisis were reported. The main methodical limitations were insufficient description of randomization or matching of patients without randomization. The main clinical limitation is a gap of data for add-on TCP with second-generation antipsychotics.

CONCLUSION

New studies are needed for add-on TCP with antipsychotic drugs in schizophrenia with predominant negative symptoms. Trials of this treatment may be possible in rare and selected cases. The therapeutic effect of add-on TCP may be explained by a strong dopaminergic activity.

Therapy response prediction in major depressive disorder: current and novel genomic markers influencing pharmacokinetics and pharmacodynamics

Major depressive disorder is connected with high rates of functional disability and mortality. About a third of the patients are at risk of therapy failure. Several pharmacogenetic markers especially located in CYP450 genes such as CYP2D6 or CYP2C19 are of relevance for therapy outcome prediction in major depressive disorder but a further optimization of predictive tools is warranted. The article summarizes the current knowledge on pharmacogenetic variants, therapy effects and side effects of important antidepressive therapeutics, and sheds light on new methodological approaches for therapy response estimation based on genetic markers with relevance for pharmacokinetics, pharmacodynamics and disease pathology identified in genome-wide association study analyses, highlighting polygenic risk score analysis as a tool for further optimization of individualized therapy outcome prediction.

Drug Repurposing in Oncology, an Attractive Opportunity for Novel Combinatorial Regimens

The costs of developing, validating and buying new drugs are dramatically increasing. On the other hand, sobering economies have difficulties in sustaining their healthcare systems, particularly in countries with an elderly population requiring increasing welfare. This conundrum requires immediate action, and a possible option is to study the large, already present arsenal of drugs approved and to use them for innovative therapies. This possibility is particularly interesting in oncology, where the complexity of the cancer genome dictates in most patients a multistep therapeutic approach. In this review, we discuss a) Computational approaches; b) preclinical models; c) currently ongoing or already published clinical trials in the drug repurposing field in oncology; and d) drug repurposing to overcome resistance to previous therapies.

Recent developments in epigenetic cancer therapeutics: clinical advancement and emerging trends

Epigenetic drug discovery field has evidenced significant advancement in the recent times. A plethora of small molecule inhibitors have progressed to clinical stage investigations and are being explored exhaustively to ascertain conclusive benefits in diverse malignancies. Literature precedents indicates that substantial amount of efforts were directed towards the use of epigenetic tools in monotherapy as well as in combination regimens at the clinical level, however, the preclinical/preliminary explorations were inclined towards the identification of prudent approaches that can leverage the anticancer potential of small molecule epigenetic inhibitors as single agents only. This review article presents an update of FDA approved epigenetic drugs along with the epigenetic inhibitors undergoing clinical stage investigations in different cancer types. A detailed discussion of the pragmatic strategies that are expected to steer the progress of the epigenetic therapy through the implementation of emerging approaches such as PROTACS and CRISPR/Cas9 along with logical ways for scaffold fabrication to selectively approach the enzyme isoforms in pursuit of garnering amplified antitumor effects has been covered. In addition, the compilation also presents the rational strategies for the construction of multi-targeting scaffold assemblages employing previously identified pharmacophores as potential alternatives to the combination therapy.

Antidepressant Medications and Weight Change: A Narrative Review

Antidepressant medications are the first-line treatment option for moderate to severe major depressive disorder. However, most antidepressants have numerous documented adverse events, including cardiometabolic effects and weight gain, which are major public health concerns. Antidepressant agents provide varying risk of associated weight gain, including significant within-class differences. Some agents, such as mirtazapine, show significant levels of weight gain, while others, such as bupropion, demonstrate weight-loss effects. Current findings suggest the role of histamine and serotonin off-target appetite-promoting pathways in adverse weight-gain effects. Therefore, controlling for undesired weight effects is an important consideration for the selection of antidepressants.

The MAO Inhibitor Tranylcypromine Alters LPS- and Aβ-Mediated Neuroinflammatory Responses in Wild-type Mice and a Mouse Model of AD

Monoamine oxidase (MAO) has been implicated in neuroinflammation, and therapies targeting MAO are of interest for neurodegenerative diseases. The small-molecule drug tranylcypromine, an inhibitor of MAO, is currently used as an antidepressant and in the treatment of cancer. However, whether tranylcypromine can regulate LPS- and/or Aβ-induced neuroinflammation in the brain has not been well-studied. In the present study, we found that tranylcypromine selectively altered LPS-induced proinflammatory cytokine levels in BV2 microglial cells but not primary astrocytes. In addition, tranylcypromine modulated LPS-mediated TLR4/ERK/STAT3 signaling to alter neuroinflammatory responses in BV2 microglial cells. Importantly, tranylcypromine significantly reduced microglial activation as well as proinflammatory cytokine levels in LPS-injected wild-type mice. Moreover, injection of tranylcypromine in 5xFAD mice (a mouse model of AD) significantly decreased microglial activation but had smaller effects on astrocyte activation. Taken together, our results suggest that tranylcypromine can suppress LPS- and Aβ-induced neuroinflammatory responses in vitro and in vivo.

Efficacy and Adverse Effects of Tranylcypromine and Tricyclic Antidepressants in the Treatment of Depression: A Systematic Review and Comprehensive Meta-analysis

PURPOSE

We conducted a comprehensive meta-analysis of the comparison of tranylcypromine (TCP) and tricyclic antidepressants (TCAs) in the treatment of depression because such work is lacking in medical scientific literature.

METHODS

Literature was searched for studies of TCP controlled by TCAs in multiple databases and in reviews of TCP and monoamine oxidase inhibitors. The natural logarithm of the odds ratio (logOR) and the pooled logOR according to a fixed effect model were calculated for the numbers of responders and nonresponders.

RESULTS

A total of 227 studies of TCP were found including 75 controlled studies of TCP-monotherapy. Twelve of 23 studies of TCP monotherapy and TCAs were excluded for several reasons (duplicates, safety studies, retrospective, cross-over), leaving 11 prospective and parallel controlled studies of TCP monotherapy versus TCAs (6 randomized double-blind). One study was excluded from the meta-analysis because of low quality of study design according to the Food and Drug Administration guidelines of studies of antidepressant drugs and high risk of bias according to the Cochrane's tool. Two studies with equal efficacy of TCP and TCAs in continuous endpoints did not provide dichotomous response data. A pooled logOR of 0.480 (95% confidence interval, 0.105-0.857, P = 0.01) resulted for the remaining eight studies in the primary meta-analysis, which favors TCP significantly over TCAs (test for heterogeneity: Х = 8.1, df = 7, P > 0.3, not heterogenous; I = 13.6%, heterogeneity not important). The result is robust with respect to inclusion of hypothetical response data of the 2 studies with continuous data only: pooled logOR, 0.350 (95% confidence interval, 0.028-0.672, P = 0.03). Visual inspection of forest plots and subgroup analysis suggest that superiority of TCP over TCAs is determined by 2 studies in psychomotor-retarded (anergic) depression.

CONCLUSIONS

Tranylcypromine and TCAs have an equal antidepressant effect in a mean sample of depressed patients with mixed psychomotor symptoms. Tranylcypromine might be superior to TCAs in depression with predominant psychomotor retardation.

Major Cardiac-Psychiatric Drug-Drug Interactions: a Systematic Review of the Consistency of Drug Databases

PURPOSE

Major depressive disorder (MDD) and anxiety disorders (AD) are both highly prevalent among individuals with arrhythmia, ischemic heart disease, heart failure, hypertension, and dyslipidemia. There should be increased support for MDD and AD diagnosis and treatment in individuals with cardiac diseases, because treatment rates have been low. However, cardiac-psychiatric drug interaction can make pharmacologic treatment challenging.

METHODS

The objective of the present systematic review was to investigate cardiac-psychiatric drug interactions in three different widely used pharmacological databases (Micromedex, Up to Date, and ClinicalKey).

RESULTS

Among 4914 cardiac-psychiatric drug combinations, 293 significant interactions were found (6.0%). When a problematic interaction is detected, it may be easier to find an alternative cardiac medication (32.6% presented some interaction) than a psychiatric one (76.9%). Antiarrhythmics are the major class of concern. The most common problems produced by these interactions are related to cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest), increased exposure of cytochrome P450 2D6 (CYP2D6) substrates, or reduced renal clearance of organic cation transporter 2 (OCT2) substrates and include hypertensive crisis, increased risk of bleeding, myopathy, and/or rhabdomyolysis.

CONCLUSION

Unfortunately, there is considerable inconsistency among the databases searched, such that a clinician's discretion and clinical experience remain invaluable tools for the management of patients with comorbidities present in psychiatric and cardiac disorders. The possibility of an interaction should be considered. With a multidisciplinary approach, particularly involving a pharmacist, the prescriber should be alerted to the possibility of an interaction. MDD and AD pharmacologic treatment in cardiac patients could be implemented safely both by cardiologists and psychiatrists.

TRIAL REGISTRATION

PROSPERO Systematic Review Registration Number: CRD42018100424.

Next-Step Treatment Considerations for Patients With Treatment-Resistant Depression That Responds to Low-Dose Intravenous Ketamine

Numerous short-term randomized trials support the acute-phase efficacy of low-dose intravenous (IV) ketamine for patients with treatment-resistant unipolar or bipolar depression. Ketamine's antidepressive effects generally have limited duration, highlighting the need for maintenance treatment after an acute-phase response. It is increasingly likely that psychiatrists will be called upon to manage the care of patients with treatment-resistant unipolar or bipolar depression who have responded acutely to ketamine and to recommend or initiate next-step treatments. However, there is a paucity of controlled evidence to guide best practices for managing treatment of patients with treatment-resistant unipolar or bipolar depression who have had a positive initial response to ketamine. This article reviews the available evidence supporting specific strategies for extending and maintaining acute antidepressive responses to low-dose IV ketamine in patients with treatment-resistant unipolar or bipolar depression and provides some preliminary considerations for clinical practice.

LSD1/KDM1A inhibitors in clinical trials: advances and prospects

Histone demethylase LSD1 plays key roles during carcinogenesis, targeting LSD1 is becoming an emerging option for the treatment of cancers. Numerous LSD1 inhibitors have been reported to date, some of them such as TCP, ORY-1001, GSK-2879552, IMG-7289, INCB059872, CC-90011, and ORY-2001 currently undergo clinical assessment for cancer therapy, particularly for small lung cancer cells (SCLC) and acute myeloid leukemia (AML). This review is to provide a comprehensive overview of LSD1 inhibitors in clinical trials including molecular mechanistic studies, clinical efficacy, adverse drug reactions, and PD/PK studies and offer prospects in this field.

The timeline of epigenetic drug discovery: from reality to dreams

The flexibility of the epigenome has generated an enticing argument to explore its reversion through pharmacological treatments as a strategy to ameliorate disease phenotypes. All three families of epigenetic proteins—readers, writers, and erasers—are druggable targets that can be addressed through small-molecule inhibitors. At present, a few drugs targeting epigenetic enzymes as well as analogues of epigenetic modifications have been introduced into the clinic use (e.g. to treat haematological malignancies), and a wide range of epigenetic-based drugs are undergoing clinical trials. Here, we describe the timeline of epigenetic drug discovery and development beginning with the early design based solely on phenotypic observations to the state-of-the-art rational epigenetic drug discovery using validated targets. Finally, we will highlight some of the major aspects that need further research and discuss the challenges that need to be overcome to implement epigenetic drug discovery into clinical management of human disorders. To turn into reality, researchers from various disciplines (chemists, biologists, clinicians) need to work together to optimise the drug engineering, read-out assays, and clinical trial design.

Suppression of LSD1 enhances the cytotoxic and apoptotic effects of regorafenib in hepatocellular carcinoma cells

Regorafenib has been approved to treat patients who have HCC progression after sorafenib failure, however, regorafenib also faces the risk of drug resistance and subsequent progression of HCC patients. As LSD1 inhibitors can alleviate acquired resistance to sorafenib, in this context, we are interested to investigate the role of LSD1 in regorafenib treatment. Firstly, over-expressed LSD1 was observed in HCC patients and predicted poor prognosis. However, regorafenib failed to suppress the expression of LSD1 in HCC cells. Thus, we hypothesized that LSD1 inhibition could enhance the anti-HCC activity of regorafenib. As expected, LSD1 knockdown could enhance anti-proliferation effect of regorafenib in HCC cells. LSD1 inhibitor SP2509 could enhance the cytotoxic and apoptotic effects of regorafenib in HCC cells. In addition, clinically used LSD1 inhibitor tranylcypromine also enhanced anti-HCC effect of regorafenib. Furthermore, LSD1 suppressed by SP2590 or tranylcypromine could alleviate the activated p-AKT (ser473) induced by regorafenib in HCC cells. Thus, inhibiting LSD1 might be an attractive target for regorafenib sensitization and clinical HCC therapy, our findings could help to elucidate more effective therapeutic options for HCC patients.

The effect of electroconvulsive therapy on cerebral monoamine oxidase A expression in treatment-resistant depression investigated using positron emission tomography

BACKGROUND

Electroconvulsive therapy (ECT) constitutes one of the most effective antidepressant treatment strategies in major depression (MDD). Despite its common use and uncontested efficacy, its mechanism of action is still insufficiently understood. Previously, we showed that ECT is accompanied by a global decrease of serotonin-1A receptors in MDD; however, further studies to investigate the involvement of the serotonergic system in the mechanism of action of ECT are warranted. The monoamine oxidase A (MAO-A) represents an important target for antidepressant treatments and was found to be increased in MDD. Here, we investigated whether ECT impacts on MAO-A levels in treatment-resistant patients (TRD).

METHODS

16 TRD patients (12 female, age 45.94 ± 9.68 years, HAMD 25.12 ± 3.16) with unipolar depression according to DSM-IV were scanned twice before (PET1 and PET2, to assess test-retest variability under constant psychopharmacotherapy) and once after (PET3) completing a minimum of eight unilateral ECT sessions using positron emission tomography and the radioligand [¹¹C]harmine to assess cerebral MAO-A distribution volumes (V_T). Age- and sex-matched healthy subjects (HC) were measured once.

RESULTS

Response rate to ECT was 87.5%. MAO-A V_T was found to be significantly reduced after ECT in TRD patients (-3.8%) when assessed in 27 a priori defined ROIs (p < 0.001). Test-retest variability between PET1 and PET2 was 3.1%. MAO-A V_T did not significantly differ between TRD patients and HC at baseline.

CONCLUSIONS

The small effect size of the significant reduction of MAO-A V_T after ECT in the range of test-retest variability does not support the hypothesis of a clinically relevant mechanism of action of ECT based on MAO-A. Furthermore, in contrast to studies reporting elevated MAO-A V_T in unmedicated depressed patients, MAO-A levels were found to be similar in TRD patients and HC which might be attributed to the continuous antidepressant pharmacotherapy in the present sample.

Monoamine oxidase inhibitors, and iron chelators in depressive illness and neurodegenerative diseases

In early 1920s, tyramine oxidase was discovered that metabolized tyramine and in 1933 Blaschko demonstrated that this enzyme also metabolized adrenaline, noradrenaline and dopamine. Zeller gave it the name monoamine oxidase (MAO) to distinguish it from the enzyme that oxidatively deaminated diamines. MAO was recognized as an enzyme of crucial interest to pharmacologists because it catalyzed the major inactivation pathway for the catecholamines (and, later, 5-hydroxytryptamine, as well). Within the few decade, the inhibitors of MAO were discovered and introduced for the treatment of depressive illness which was established clinically. However, the first clinical use exposed serious side effects, pharmacological interest in, and investigation of, MAO continued, resulting in the characterization of two forms, distinct forms, MAO-A and -B, and selective inhibitors for them. Selective inhibitors of MAO-B (selegiline, rasagiline and safinamide) have found a therapeutic role in the treatment of Parkinson's disease and reversible inhibitors of MAO-A offered antidepressant activity without the serious side effects of the earlier nonselective MAO inhibitors. Subsequent molecular pharmacological have also generated the concept of neuroprotection, reflecting the possibility of slowing, halting and maybe reversing, neurodegeneration in Parkinson's or Alzheimer's diseases. Increased levels of oxidative stress through the accumulation of iron in the Parkinsonian and Alzheimer brains has been suggested to be critical for the initiation and progress of neurodegeneration. Selective inhibition of brain MAO could contribute importantly to lowering such stress, preventing the formation of hydrogen peroxide. Interaction of Iron with hydrogen peroxide and lead to Fenton reaction and production of the most reactive radical, namely hydroxyl radical. There are complex interactions between free iron levels in brain and MAO, and cascade of neurotoxic events may have practical outcomes for depressive disorders and neurodegenerative diseases. As consequence recent novel therapeutic drugs for neurodegenerative diseases has led to the development of multi target drugs, that possess selective brain MAO A and B inhibitory moiety, iron chelating and antioxidant activities and the ability to increase brain levels of endogenous neurotrophins, such as BDNF, GDNF VEGF and erythropoietin and induce mitochondrial biogenesis.

A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths

This review appraises over 150 recent original papers reporting data that demonstrate the greatly reduced tyramine content of modern-day 'foods', about which the medical literature has a paucity of information. It discusses the cardiovascular pharmacology of tyramine and the characteristics, extent, risks, and treatment of the blood pressure increases that sometimes result from tyramine ingestion (the pressor response). In past decades, cheese was the only food associated with documented fatalities resulting from hypertension. Today, few foods contain problematically high tyramine levels, which is a result of changes in international food production techniques (especially the use of starter cultures), and hygiene regulations. Nowadays, even 'matured' cheeses are usually safe in healthy-sized portions. The mechanism by which tyramine may be produced in foods (by certain micro-organisms) is explained and hundreds of recent estimations of cheeses are reviewed. Numerous other previously inadequately documented foods are reviewed, including fish and soy sauces, salami-type sausages, dried meats, beers, wines, and various condiments. Evidence that the risk of harm from the pressor response has previously been overstated is reviewed, and the iatrogenic harms from hasty and aggressive treatment of hypertensive urgency are re-evaluated. Evidence now suggests that MAOIs are of comparable safety to many newer drugs and are straightforward to use. Previously held concerns about MAOIs are misplaced and some are of over-estimated consequence. The variability of pressor sensitivity to tyramine between individuals means that the knowledge and judgement of doctors, and some care, are still required.