Efficacy of Carbamazepine and Its Derivatives in the Treatment of Bipolar Disorder

Global Trends in the Use of Pharmacotherapy for the Treatment of Bipolar Disorder

Bipolar Disorder (BD) is a chronic mental health condition characterized by significant mood swings, including periods of mania or hypomania and depression. Affecting approximately 1-2% of the global population, BD is associated with impaired social functioning, decreased quality of life, and an increased risk of suicide. The disorder presents a substantial burden on healthcare systems and imposes significant economic costs due to lost productivity and the need for extensive treatment and support services. This comprehensive review synthesizes global trends in BD pharmacotherapy over the past 1 to 3 years, focusing on emerging medications, novel treatment protocols, and ongoing debates within the field. Additionally, the review explores differences in prescribing patterns across developed and developing countries, introduces the impact of pharmacogenomics and personalized medicine on treatment outcomes. PURPOSE OF REVIEW: The primary purpose of this review is to provide a comprehensive and up-to-date synthesis of the global trends in the use of medications for the treatment of BD over the past 1 to 3 years. This review aims to outline the latest studies, clinical trials, and meta-analyses relevant to BD pharmacotherapy, highlighting new discoveries and advancements. Furthermore, this review will address ongoing debates and controversies in the field, such as the role of antidepressants in BD treatment and the long-term use of antipsychotics, aiming to bridge knowledge gaps and guide future research directions. RECENT FINDINGS: Studies continue to reinforce the efficacy of lithium in mood stabilization and reduction of suicidal behavior, despite its declining use due to safety concerns. Mood stabilizing anticonvulsants like valproate and carbamazepine continue to be vital alternatives, each with distinct side effect profiles necessitating careful patient monitoring. The approval and increasing use of novel atypical antipsychotics, such as lurasidone (2013) and cariprazine (2015), has expanded treatment options, offering efficacy in different phases of BD with relatively favorable side effect profiles. Antidepressants remain contentious, with evidence suggesting their benefits primarily when used in combination with mood stabilizers. Emerging agents like lumateperone (Dec 2021) and esketamine show promise, while pharmacogenomic research is paving the way for more personalized treatments. The landscape of BD pharmacotherapy is marked by significant advancements and ongoing challenges. Lithium and mood stabilizing anticonvulsants remain foundational treatments, albeit with adherence challenges and side effect concerns. The advent of new atypical antipsychotics and novel agents offers promising therapeutic options, while antidepressants continue to be debated. Personalized medicine and pharmacogenomics could emerge as transformative approaches, allowing for more tailored and effective treatments. However, disparities in medication accessibility between developed and developing countries highlight the need for global collaboration to optimize BD management. Continued research and innovation are essential to addressing the complexities of BD and improving patient outcomes worldwide.

Discovery of non-steroidal aldo-keto reductase 1D1 inhibitors through automated screening and in vitro evaluation

Steroid hormones regulate a wide range of physiological processes in the human body. However, exposure to xenobiotics can disrupt the hormonal balance by inhibition of enzymes involved in hormone synthesis or metabolism. Aldo-keto reductase 1D1 (AKR1D1) plays a key role in bile acid and steroid hormone metabolism by catalyzing the reduction of the double bond between C4 and C5 atoms of Δ(4)-steroids. In our previous work, we developed a model to screen for steroid-like xenobiotics that inhibit AKR1D1. In the current study, we used this model to screen for novel non-steroidal inhibitors. By applying an automatized screening approach, based on molecular docking and scoring in combination with post-docking refinement, 45 compounds were detected as potential hits and selected for in vitro evaluation. Among them, zardaverine was identified as the most potent inhibitor, with an IC50 value of 2.32 ± 1.27 μM. Other moderate inhibitors included carbamazepine, larotrectinib, endosulfan II, megastigmatrienone A, and mizolastine. The structural diversity of the identified inhibitors demonstrates that the binding site of AKR1D1 is rather promiscuous and can accommodate a broad range of ligands. These findings underscore the importance of toxicity screening and potential to identify structurally different AKR1D1 inhibitors.

Neurotoxic effects of carbamazepine on the mosquitofish Gambusia affinis

In recent years, the presence of pharmaceuticals in the aquatic environment has gained a significant attention. Carbamazepine, a commonly prescribed antiepileptic drug, has been consistently found in aquatic environments at concentrations ranging from nanograms to micrograms, raising concerns about its potential negative impacts on aquatic organisms. The study examined the acute and chronic neurotoxic effects of environmentally relevant and sublethal concentrations of carbamazepine in the mosquitofish Gambusia affinis. After a 96-hour exposure period, the median lethal concentration (LC50) of carbamazepine for G. affinis was determined as 24 mg L - 1. For the current study, sublethal concentrations i.e., one-tenth (2.4 mg L - 1) and one-fifth (4.8 mg L - 1) of the LC50 value were chosen for assessing the neurotoxic effects along with the environmentally relevant concentration (13 ng L - 1). The research findings indicated that carbamazepine had a disruptive impact on the typical growth and behavior of the fish. During the acute exposure phase, physical deformities were observed in the fish, resulting in neonatal and postneonatal fatalities. Furthermore, the neurotoxic effects of carbamazepine were clearly demonstrated through alterations in various neurological parameters, including acetylcholinesterase, dopamine, gamma-aminobutyric acid, serotonin, monoamine oxidase, 5-hydroxyindole acetic acid, adrenaline, and nor-adrenaline. These findings raise concerns about the survival of fish populations in their natural environment.

Subchronic Treatment with CBZ Transiently Attenuates Its Anticonvulsant Activity in the Maximal Electroshock-Induced Seizure Test in Mice

The objective of this study is to evaluate the anticonvulsant efficacy of carbamazepine (CBZ) following acute and chronic administration across four treatment protocols in a murine model of maximal electroshock-induced seizures. A single dose of the drug was utilized as a control. The neurotoxic effects were evaluated in the chimney test and the passive avoidance task. Furthermore, plasma and brain concentrations of CBZ were quantified across all treatment protocols. The subchronic administration of CBZ (7 × 2 protocol) resulted in an attenuation of its antielectroshock effect. In the three remaining treatment regimens (7 × 1, 14 × 1, and 14 × 2) the median effective doses of CBZ were comparable to the control. Neither acute nor chronic treatment with CBZ resulted in a discernible impact on motor coordination or long-term memory. The plasma and brain concentrations of CBZ were significantly lower in most chronic protocols when compared to a single-dose application. This may explain the transient attenuation of CBZ effectiveness in the 7 × 2 protocol, but not the return to the previous level. The anticonvulsant and neurotoxic profiles of CBZ did not differ after single and chronic administration. Therefore, experimental chronic studies with CBZ are not prerequisites for concluding and possibly translating results to clinical conditions.

Off-label use of medicines in South Africa: a review

BACKGROUND

Off-label use of medicinal products has become an important part of mainstream and legitimate medical practice worldwide. This practice is common in oncology, obstetrics, paediatrics, and in the management of infectious diseases (notably HIV), and inflammatory conditions as well as in rare and/or orphan diseases. However, the off-label use of medicines recently-raised many clinical and legal difficulties, not only among medical practitioners but also among pharmacists and other healthcare professionals.

AIM

This paper, therefore, highlights the advantages (such as cost saving for both the patient and the country/insurance that is paying for the medication) and disadvantages (insufficient evidence available) of the use of medicines to treat specific conditions or indications for which they are currently not registered.

CONCLUSION

Off-label drug use can be likened to a double-edged sword, offering valuable opportunities for medical practitioners while carrying potential risks. When the scientific basis for off-label use is unclear, it may place patients at risk of unapproved experimentation, unforeseen health hazards, and ineffective treatments. Hence, there is a pressing need in South Africa for clear regulatory guidelines on off-label drug use. Additionally, the timely review and approval of new indications for medicines, backed by robust scientific evidence, are essential. This would reduce the significant burden and inherent risks faced by medical practitioners when using medicines off-label to provide compassionate care.

Neurophysiological profiles of patients with bipolar disorders as probed with transcranial magnetic stimulation: A systematic review

AIM

Bipolar disorder (BD) has a significant impact on global health, yet its neurophysiological basis remains poorly understood. Conventional treatments have limitations, highlighting the need for a better understanding of the neurophysiology of BD for early diagnosis and novel therapeutic strategies.

DESIGN

Employing a systematic review approach of the PRISMA guidelines, this study assessed the usefulness and validity of transcranial magnetic stimulation (TMS) neurophysiology in patients with BD.

METHODS

Databases searched included PubMed, MEDLINE, Embase, and PsycINFO, covering studies from January 1985 to January 2024.

RESULTS

Out of 6597 articles screened, nine studies met the inclusion criteria, providing neurophysiological insights into the pathophysiological basis of BD using TMS-electromyography and TMS-electroencephalography methods. Findings revealed significant neurophysiological impairments in patients with BD compared to healthy controls, specifically in cortical inhibition and excitability. In particular, short-interval cortical inhibition (SICI) was consistently diminished in BD across the studies, which suggests a fundamental impairment of cortical inhibitory function in BD. This systematic review corroborates the potential utility of TMS neurophysiology in elucidating the pathophysiological basis of BD. Specifically, the reduced cortical inhibition in the SICI paradigm observed in patients with BD suggests gamma-aminobutyric acid (GABA)-A receptor-mediated dysfunction, but results from other TMS paradigms have been inconsistent. Thus, complex neurophysiological processes may be involved in the pathological basis underlying BD. This study demonstrated that BD has a neural basis involving impaired GABAergic function, and it is highly expected that further research on TMS neurophysiology will further elucidate the pathophysiological basis of BD.

The impact of pregnancy-related hormonal and physiological changes on antiseizure medications: expert perspective

INTRODUCTION

Epilepsy is a disorder of recurrent, unprovoked seizures affecting approximately 15 million individuals of childbearing potential worldwide. Patients with epilepsy rely on regular daily therapy with antiseizure medications (ASMs). Furthermore, ASMs are also prescribed for other neuropsychiatric indications (e.g. bipolar disorder, pain, migraines) with over 2% of the pregnancies in the United States involving prenatal exposure to ASMs.

AREAS COVERED

ASM concentrations are affected by hormonal and physiological changes in pregnancy, including increases in renal and hepatic blood flow, decreased protein binding, and changes in enzyme activity. Clearance changes typically reverse within a few weeks after delivery. During pregnancy, many ASMs, such as lamotrigine, levetiracetam, and oxcarbazepine, should have serum concentrations monitored and doses increased to maintain the individualized target range for seizure control. ASMs metabolized via glucuronidation, primarily lamotrigine, undergo marked increases in clearance throughout pregnancy, requiring about 3-fold the pre-pregnancy daily dose by delivery. Postpartum, ASM doses are usually decreased over several weeks to prevent drug toxicity.

EXPERT OPINION

In the future, the development of a physiologically-based pharmacokinetic model for various ASMs may enable empiric dose adjustments in pregnancy without the difficulties of frequent therapeutic drug monitoring.

Treatment of bipolar depression: clinical practice vs. adherence to guidelines-data from a Bavarian drug surveillance project

Objectives

Pharmacotherapy of bipolar depression (BPD) is confronted with major clinical challenges, like limited evidence-based treatment options, regular cases of treatment resistance, and risk of treatment-emergent affective switches. Medical guidelines can support practitioners to make decisions based on current scientific evidence. The objective of this study is to evaluate to what extent recommendations of the 2019 German S3 guidelines "Diagnosis and Treatment of Bipolar Disorders" are reflected in clinical practice in inpatient treatment.

Methods

We conducted a descriptive analysis of prescription numbers in 2,627 patients with BPD in a naturalistic inpatient setting analyzing data from the ongoing Bavarian multicenter drug safety project Pharmaco-Epidemiology and Vigilance (Pharmako-EpiVig) from the years 2014-2022.

Results

Of the patients, 38% were not administered any drug explicitly recommended for treatment of BPD, that is, quetiapine, lamotrigine, carbamazepine, or olanzapine. Only 6% of the patients received monotherapy with one of those drugs. Of the patients, 34% were administered ≥4 psychotropic drugs simultaneously. Patients received 912 different therapy regimens of mono or combination therapy with mood stabilizers (MS), atypical antipsychotics (AAP), and antidepressants. Of the patients, 72% received an antidepressant and 6% without concomitant prescription of an AAP or MS. Prescription rates of venlafaxine (21% to 14%) and tricyclic antidepressants (9% to 6%) decreased significantly from the first (2014-2016) to the last (2020-2022) observed time period. Of the patients, 60% received an MS. Prescription rate of valproate (22% to 14%) decreased significantly, while lithium prescription increased significantly (29% to 35%). Of the patients, 71% were administered an AAP. Quetiapine was the most prescribed drug overall (43%). Only two patients were administered a combination of olanzapine and fluoxetine.

Conclusion

Our results demonstrate a substantial gap between guideline recommendations and current clinical practice. The remarkable heterogeneity in treatment regimens, with no discernible dominant treatment approach, is in part a reflection of the complexity of bipolar disorder but also substantiates the need of comprehensive recommendations regarding combination therapies. Increase in lithium prescription is an encouraging development due to its unique efficacy in maintenance treatment. To improve the quality of clinical practice guideline implementation, more randomized controlled trials should be conducted in the future to prospectively investigate different implementation strategies.

Insight into the generation of toxic by-products during UV/H2O2 degradation of carbamazepine: Mechanisms, N-transformation and toxicity

Carbamazepine (CBZ) is a widely used anticonvulsant drug that has been detected in aquatic environments. This study investigated the toxicity of its by-products (CBZ-BPs), which may surpass CBZ. Unlike the previous studies, this study offered a more systematic approach to identifying toxic BPs and inferring degradation pathways. Furthermore, quadrupole time-of-flight (QTOF) and density functional theory (DFT) calculations were employed to analyze CBZ-BP structures and degradation pathways. Evaluation of total organic carbon (TOC) and total nitrogen (TN) mineralization rates, revealed carbon (C) greater susceptibility to mineralization compared with nitrogen (N). Furthermore, three rules were established for CBZ decarbonization and N removal during degradation, observing the transformation of aromatic compounds into aliphatic hydrocarbons and stable N-containing organic matter over time. Five potentially highly toxic BPs were screened from 14 identified BPs, with toxicity predictions guiding the selection of commercial standards for quantification and true toxicity testing. Additionally, BP207 emerged as the most toxic, supported by the predictive toxicity accumulation model (PTAM). Notably, highly toxic BPs feature an acridine structure, indicating its significant contribution to toxicity. These findings offered valuable insights into the degradation mechanisms of emerging contaminants and the biosafety of aquatic environments during deep oxidation.

Global trends and hotspots in pain associated with bipolar disorder in the last 20 years: a bibliometric analysis

Purpose

The prevalence of comorbid pain and Bipolar Disorder in clinical practice continues to be high, with an increasing number of related publications. However, no study has used bibliometric methods to analyze the research progress and knowledge structure in this field. Our research is dedicated to systematically exploring the global trends and focal points in scientific research on pain comorbidity with bipolar disorder from 2003 to 2023, with the goal of contributing to the field.

Methods

Relevant publications in this field were retrieved from the Web of Science core collection database (WOSSCC). And we used VOSviewer, CiteSpace, and the R package "Bibliometrix" for bibliometric analysis.

Results

A total of 485 publications (including 360 articles and 125 reviews) from 66 countries, 1019 institutions, were included in this study. Univ Toront and Kings Coll London are the leading research institutions in this field. J Affect Disorders contributed the largest number of articles, and is the most co-cited journal. Of the 2,537 scholars who participated in the study, Stubbs B, Vancampfort D, and Abdin E had the largest number of articles. Stubbs B is the most co-cited author. "chronic pain," "neuropathic pain," "psychological pain" are the keywords in the research.

Conclusion

This is the first bibliometric analysis of pain-related bipolar disorder. There is growing interest in the area of pain and comorbid bipolar disorder. Focusing on different types of pain in bipolar disorder and emphasizing pain management in bipolar disorder are research hotspots and future trends. The study of pain related bipolar disorder still has significant potential for development, and we look forward to more high-quality research in the future.

Therapeutic Drug Monitoring in Psychiatry: Enhancing Treatment Precision and Patient Outcomes

Psychiatric disorders often require pharmacological interventions to alleviate symptoms and improve quality of life. However, achieving an optimal therapeutic outcome is challenging due to several factors, including variability in the individual response, inter-individual differences in drug metabolism, and drug interactions in polytherapy. Therapeutic drug monitoring (TDM), by measuring drug concentrations in biological samples, represents a valuable tool to address these challenges, by tailoring medication regimens to each individual. This review analyzes the current landscape of TDM in psychiatric practice, highlighting its significance in optimizing drug dosages, minimizing adverse effects, and improving therapeutic efficacy. The metabolism of psychiatric medications (i.e., mood stabilizers, antipsychotics, antidepressants) often exhibits significant inter-patient variability. TDM can help address this variability by enhancing treatment personalization, facilitating early suboptimal- or toxic-level detection, and allowing for timely interventions to prevent treatment failure or adverse effects. Furthermore, this review briefly discusses technological advancements and analytical methods supporting the implementation of TDM in psychiatric settings. These innovations enable quick and cost-effective drug concentration measurements, fostering the widespread adoption of TDM as a routine practice in psychiatric care. In conclusion, the integration of TDM in psychiatry can improve treatment outcomes by individualizing medication regimens within the so-called precision medicine.

Neuroprotective Properties of Antiepileptics: What are the Implications for Psychiatric Disorders?

Since the discovery of the first antiepileptic compound, increasing attention has been paid to antiepileptic drugs (AEDs), and recently, with the understanding of the molecular mechanism underlying cells death, a new interest has revolved around a potential neuroprotective effect of AEDs. While many neurobiological studies in this field have focused on the protection of neurons, growing data are reporting how exposure to AEDs can also affect glial cells and the plastic response underlying recovery; however, demonstrating the neuroprotective abilities of AEDs remains a changeling task. The present work aims to summarize and review the literature available on the neuroprotective properties of the most commonly used AEDs. Results highlighted how further studies should investigate the link between AEDs and neuroprotective properties; while many studies are available on valproate, results for other AEDs are very limited and the majority of the research has been carried out on animal models. Moreover, a better understanding of the biological basis underlying neuro-regenerative defects may pave the way for the investigation of further therapeutic targets and eventually lead to an improvement in the actual treatment strategies.

Management Strategies for Borderline Personality Disorder and Bipolar Disorder Comorbidities in Adults with ADHD: A Narrative Review

This narrative review examines two of the common comorbidities of attention-deficit/hyperactivity disorder, bipolar disorder (BD), and borderline personality disorder (BPD), which each share several common features with ADHD that can make assessment and diagnosis challenging. The review highlights some of the key symptomatic differences between adult ADHD and these disorders, allowing for more careful consideration before establishing a formal diagnosis. When the disorders are found to be comorbid, further complications may arise; thus, the review will also help to provide evidence-based treatment recommendations as well as suggestions on how to minimize adverse events. Incorporating evidence from systematic reviews, journal articles, randomized controlled trials, and case reports, this review highlights that the diagnosis of ADHD and some of its common comorbidities is challenging and requires full, in-depth assessment and management. The management strategies of these comorbidities will also be addressed, with emphasis on achieving mood stabilization for BD prior to initiating appropriate ADHD pharmacotherapy. Medications, specifically mood stabilizers, antipsychotics, and antidepressants, are fundamental in treating symptoms seen in BD and some cases of BPD, alongside psychotherapy and lifestyle modifications when appropriate. The review highlights the effectiveness of specific medications, including psychostimulants, atomoxetine, and bupropion, as add-on therapies to mood-stabilizing treatments for addressing ADHD symptoms in patients with these comorbidities. Despite limited research, the review will address various pharmacological and psychotherapeutic approaches for managing comorbid ADHD and BPD, emphasizing the need for further investigations to better understand the unique needs of this patient population.

Effects of carbamazepine on the central nervous system of zebrafish at human therapeutic plasma levels

The fish plasma model (FPM) facilitated the environmental risk assessment of human drugs by using existing data on human therapeutic plasma concentrations (HTPCs) and predicted fish plasma concentrations (FPCs). However, studies on carbamazepine (CMZ) with both the mode of action (MOA) based biological effects at molecular level (such as neurotransmitter and gene level) and measured FPCs are lacking. Bioconcentration of CMZ in adult zebrafish demonstrated that the FPM underestimated the bioconcentration factors (BCFs) in plasma at environmental CMZ exposure concentrations (1-100 μg/L). CMZ significantly increased Glu and GABA, decreased ACh and AChE as well as inhibited the transcription levels of gabra1, grin1b, grin2b, gad1b, and abat when the actual FPCs were in the ranges of 1/1000 HTPC to HTPC. It is the first read-across study of CMZ integrating MOA-based biological effects at molecular level and FPCs. This study facilitates model performance against a range of different drug classes.

Diagnosis and Treatment of Bipolar Disorder: A Review

Importance

Bipolar disorder affects approximately 8 million adults in the US and approximately 40 million individuals worldwide.

Observations

Bipolar disorder is characterized by recurrent episodes of depression and mania or hypomania. Bipolar depressive episodes are similar to major depressive episodes. Manic and hypomanic episodes are characterized by a distinct change in mood and behavior during discrete time periods. The age of onset is usually between 15 and 25 years, and depression is the most frequent initial presentation. Approximately 75% of symptomatic time consists of depressive episodes or symptoms. Early diagnosis and treatment are associated with a more favorable prognosis. Diagnosis and optimal treatment are often delayed by a mean of approximately 9 years following an initial depressive episode. Long-term treatment consists of mood stabilizers, such as lithium, valproate, and lamotrigine. Antipsychotic agents, such as quetiapine, aripiprazole, asenapine, lurasidone, and cariprazine, are recommended, but some are associated with weight gain. Antidepressants are not recommended as monotherapy. More than 50% of patients with bipolar disorder are not adherent to treatment. Life expectancy is reduced by approximately 12 to 14 years in people with bipolar disorder, with a 1.6-fold to 2-fold increase in cardiovascular mortality occurring a mean of 17 years earlier compared with the general population. Prevalence rates of metabolic syndrome (37%), obesity (21%), cigarette smoking (45%), and type 2 diabetes (14%) are higher among people with bipolar disorder, contributing to the risk of early mortality. The annual suicide rate is approximately 0.9% among individuals with bipolar disorder, compared with 0.014% in the general population. Approximately 15% to 20% of people with bipolar disorder die by suicide.

Conclusions and Relevance

Bipolar disorder affects approximately 8 million adults in the US. First-line therapy includes mood stabilizers, such as lithium, anticonvulsants, such as valproate and lamotrigine, and atypical antipsychotic drugs, such as quetiapine, aripiprazole, asenapine, lurasidone, and cariprazine.

A 5-Year Study of Antiseizure Medications (ASMs) Monitoring in Patients with Neuropsychiatric Disorders in an Italian Clinical Center

Despite receiving appropriate antiseizure medications (ASMs), a relevant percentage of neuropsychiatric patients do not benefit from this approach, and one reason is subtherapeutic ASMs plasma concentration (C(p)) due to improper drug adherence, interindividual pharmacokinetic differences, or metabolic interactions among different drugs. For these reasons, therapeutic drug monitoring (TDM) by measuring ASMs C(p) is an effective tool that improves pharmacological therapies in clinical practice. Based on these premises, in the present real-world study, we analyzed the C(p) of the most used ASMs in diverse medical conditions, which were assayed during the years 2018-2022 at the University Hospital of Pisa, including about 24,000 samples. This population was largely heterogeneous, and our database did not contain clinical information about the patients. The most used ASMs were Valproate (VPA: 54.5%) and Levetiracetam (LEV: 18.6%), followed by Oxcarbazepine (OxCBZ: 8.3%) and Carbamazepine (CBZ: 7.2%), whereas the associations LEV/VPA, Ethosuximide (ESM)/VPA, and CBZ/VPA were the most frequently proposed. In about 2/3 of assays, ASMs C(p) was in range, except for VPA, which was underdosed in almost half of the samples. Importantly, toxic levels of ASMs C(p) were found very rarely. For VPA, there was a decrease of mean C(p) across ages, from adolescents to older patients, while the C(p) of LEV, CBZ, OxCBZ, and Topiramate (TPM) showed a slight tendency to increase. When we compared females and males, we found that for VPA, the average age was higher for females, whereas women taking Lamotrigine (LTG) and OxCBZ were younger than men. Then, comparing ASMs used in neurologic and psychiatric disorders, based on the request form, it emerged that the mean C(p) of CBZ, OxCBZ, and LTG on samples collected in the Psychiatric Unit was lower compared to the Neurology and Child Neuropsychiatry Units. Finally, the ASMs subjected to multiple dosing starting from an initial subtherapeutic C(p) increased their level at different time points within a year, reaching the reference range for some of them. In conclusion, the present study suggests that TDM is widely applied to monitor ASMs C(p), finding many of them within the reference range, as a demonstration of its utility in clinical practice.

Reduction of Genotoxicity of Carbamazepine to Human Lymphocytes by Pre-treatment with Vitamin B12

BACKGROUND

Carbamazepine (CBZ) is widely used as an anti-epileptic drug. Vitamin B12 has been shown to protect against DNA damage caused by several mutagenic agents.

OBJECTIVE

This study aimed to investigate the effect of vitamin B12 on CBZ-induced genotoxicity in cultured human lymphocytes.

METHODS

Sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) genotoxic assays were utilized to achieve the study objective.

RESULTS

The results showed significantly higher frequencies of CAs and SCEs in the CBZ-treated cultures (12 μg/mL) compared to the control group (P<0.01). The genotoxic effects of CBZ were reduced by pre-treatment of cultures with vitamin B12 (13.5μg/ml, P<0.05). Neither CBZ nor vitamin B-12 showed any effects on mitotic and proliferative indices.

CONCLUSION

CBZ is genotoxic to lymphocyte cells, and this genotoxicity can be reduced by vitamin B12.

Mingmu Xiaoyao granules regulate the PI3K/Akt/mTOR signaling pathway to reduce anxiety and depression and reverse retinal abnormalities in rats

Objective: To investigate the effects of Mingmu Xiaoyao granules (MMXY) on the morphology and function of the retina and the mechanism of PI3K/Akt/mTOR pathway-related proteins in rats with anxiety and depression induced by chronic unpredictable mild stress (CUMS).

Methods: Fifty-two male Sprague Dawley rats were randomly allocated to either a control (n = 14) or a simulated CUMS group (n = 38). The CUMS model was established successfully at 4 weeks. Six rats in each group were randomly selected to be sacrificed and their retinas isolated for histological examination. At 5 weeks, rats in the CUMS group were randomly allocated to the following groups: Model (CUMS + pure water), MMXY-H (CUMS + MMXY 7.2 g/kg/d), MMXY-L (CUMS + MMXY 3.6 g/kg/d), and CBZ (CUMS + Carbamazepine 20 mg/kg/d), with eight rats in each group. All rats were given the relevant intervention once a day. At 12 weeks, sucrose preference and open field tests were performed to evaluate the anxiety and depression status of rats. In live rats, optical coherence tomography angiography was used to measure retinal thickness and blood flow, while electroretinograms (ERGs) and visual evoked potentials (VEPs) were used to evaluate retinal function. The next day, the specimens were sacrificed for serological, histological, immunofluorescence, Western blot and transmission electron microscopy examinations to explore the mechanism of MMXY in CUMS rats.

Results: MMXY improved the anxiety and depression-like behavior of rats. Results of optical coherence tomography angiography showed that MMXY improved retinal inner thickness and blood flow in CUMS rats. MMXY improved the amplitude of a- and b-waves in the scotopic and photopic ERG, as well as N2 and P2 peak time and amplitude in the flash-VEP in CUMS rats. Retinal histological staining and transmission electron microscopy showed that MMXY reversed retinal morphology and ultrastructure in CUMS rats. MMXY reduced the expression of Beclin1 and LC3I/II proteins, regulated the PI3K/Akt/mTOR pathway, inhibited autophagy, and had a protective effect on the retina in CUMS rats.

Conclusion: MMXY may effectively improve retinal morphology and function as well as anxiety and depression-like behaviors in CUMS rats by regulating the PI3K/Akt/mTOR signaling pathway.

Characterization in Inhibitory Effectiveness of Carbamazepine in Voltage-Gated Na+ and Erg-Mediated K+ Currents in a Mouse Neural Crest-Derived (Neuro-2a) Cell Line

Carbamazepine (CBZ, Tegretol®) is an anticonvulsant used in the treatment of epilepsy and neuropathic pain; however, several unwanted effects of this drug have been noticed. Therefore, the regulatory actions of CBZ on ionic currents in electrically excitable cells need to be reappraised, although its efficacy in suppressing voltage-gated Na+ current (INa) has been disclosed. This study was undertaken to explore the modifications produced by CBZ on ionic currents (e.g., INa and erg-mediated K+ current [IK(erg)]) measured from Neuro-2a (N2a) cells. In these cells, we found that this drug differentially suppressed the peak (transient, INa(T)) and sustained (late, INa(L)) components of INa in a concentration-dependent manner with effective IC50 of 56 and 18 μM, respectively. The overall current-voltage relationship of INa(T) with or without the addition of CBZ remained unchanged; however, the strength (i.e., ∆area) in the window component of INa (INa(W)) evoked by the short ascending ramp pulse (Vramp) was overly lessened in the CBZ presence. Tefluthrin (Tef), a synthetic pyrethroid, known to stimulate INa, augmented the strength of the voltage-dependent hysteresis (Hys(V)) of persistent INa (INa(P)) in response to the isosceles-triangular Vramp; moreover, further application of CBZ attenuated Tef-mediated accentuation of INa(P)'s Hys(V). With a two-step voltage protocol, the recovery of INa(T) inactivation seen in Neuro-2a cells became progressively slowed by adding CBZ; however, the cumulative inhibition of INa(T) evoked by pulse train stimulation was enhanced during exposure to this drug. Neuro-2a-cell exposure to CBZ (100 μM), the magnitude of erg-mediated K+ current measured throughout the entire voltage-clamp steps applied was mildly inhibited. The docking results regarding the interaction of CBZ and voltage-gate Na+ (NaV) channel predicted the ability of CBZ to bind to some amino-acid residues in NaV due to the existence of a hydrogen bond or hydrophobic contact. It is conceivable from the current investigations that the INa (INa(T), INa(L), INa(W), and INa(P)) residing in Neuro-2a cells are susceptible to being suppressed by CBZ, and that its block on INa(L) is larger than that on INa(T). Collectively, the magnitude and gating of NaV channels produced by the CBZ presence might have an impact on its anticonvulsant and analgesic effects occurring in vivo.

The pharmacotherapeutic management of comorbid bipolar disorder and alcohol use disorder

INTRODUCTION

Comorbidity of bipolar disorder (BD) and alcohol use disorder (AUD) is very frequent resulting in detrimental outcomes, including increased mortality. Diagnosis of AUD in BD and vice versa is often delayed as symptoms of one disorder mimic and obscure the other one. Evidence for pharmacotherapies for people with comorbid BD and AUD remains limited, and further proof-of-concept studies are urgently needed.

AREAS COVERED

This paper explores the currently available pharmacotherapies for AUD, BD and their usefulness for comorbid BD and AUD. It also covers to some degree the epidemiology, diagnosis, and potential common neurobiological traits of comorbid BD and AUD.

EXPERT OPINION

The authors conclude that more controlled studies are needed before evidence-based guidance can be drawn up for clinician's use. Since there are no relevant pharmacological interactions, approved medications for AUD can also be used safely in BD. For mood stabilization, lithium should be considered first in adherent persons with BD and comorbid AUD. Alternatives include valproate, lamotrigine, and some atypical antipsychotics, with partial D2/D3 receptor agonism possibly being beneficial in AUD, too.

Carbamazepine Overdose after Psychiatric Conditions: A Case Study for Postmortem Analysis in Human Bone

Carbamazepine is the main option used as a preventive medication to treat bipolar disorder when there is no response to lithium. Carbamazepine toxicity is defined as serum levels greater than 12 μg/mL, with severe toxicity occurring over 40 μg/mL, reduced to 30 μg/mL when combined with pharmacological treatment, i.e., benzodiazepines or antidepressants. For these reasons, it is necessary to find a validated tool to determine carbamazepine levels in an autopsy to rule out suicide or to know if the death was a consequence of an adverse drug reaction (ADR), especially when only bones can be accessed. We have validated a tool to detect and quantify drug concentration in bone. Our results showed a peak for carbamazepine at minute 12 and a mass fragment of 193 m/z. This case study is the first time in the literature that carbamazepine has been detected and quantified in bone. These results demonstrate that carbamazepine can be detected in bone tissue from forensic cases, but almost more importantly, that the method proposed is valid, reliable, and trustworthy.

Mycotherapy: Potential of Fungal Bioactives for the Treatment of Mental Health Disorders and Morbidities of Chronic Pain

Mushrooms have been used as traditional medicine for millennia, fungi are the main natural source of psychedelic compounds. There is now increasing interest in using fungal active compounds such as psychedelics for alleviating symptoms of mental health disorders including major depressive disorder, anxiety, and addiction. The anxiolytic, antidepressant and anti-addictive effect of these compounds has raised awareness stimulating neuropharmacological investigations. Micro-dosing or acute dosing with psychedelics including Lysergic acid diethylamide (LSD) and psilocybin may offer patients treatment options which are unmet by current therapeutic options. Studies suggest that either dosing regimen produces a rapid and long-lasting effect on the patient post administration with a good safety profile. Psychedelics can also modulate immune systems including pro-inflammatory cytokines suggesting a potential in the treatment of auto-immune and other chronic pain conditions. This literature review aims to explore recent evidence relating to the application of fungal bioactives in treating chronic mental health and chronic pain morbidities.

The Purinergic System as a Target for the Development of Treatments for Bipolar Disorder

The neurobiological and neurochemical mechanisms underlying the pathophysiology of bipolar disorder are complex and not yet fully understood. From circadian disruption to neuroinflammation, many pathways and signaling molecules are important contributors to bipolar disorder development, some specific to a disease subtype or a cycling episode. Pharmacological agents for bipolar disorder have shown only partial efficacy, including mood stabilizers and antipsychotics. The purinergic hypothesis for bipolar disorder emerges in this scenario as a promising target for further research and drug development, given its role in neurotransmission and neuroinflammation that results in behavioral and mood regulation. Here, we review the basic concepts of purinergic signaling in the central nervous system and its contribution to bipolar disorder pathophysiology. Allopurinol and novel P2X7 receptor antagonists are promising candidates for treating bipolar disorder. We further explore currently available pharmacotherapies and the emerging new purinergic targets for drug development in bipolar disorder.