Review of toxicity and trends in the use of tiagabine as reported to US poison centers from 2000 to 2012

Critical appraisal and systematic review of genes linked with cocaine addiction, depression and anxiety

Recent lifestyle changes have resulted in tremendous peer pressure and mental stress, and increased the incidences of chronic psychological disorders; like addiction, depression and anxiety (ADA). In this context, the stress-tolerance levels vary amongst individuals and genetic factors play prominent roles. Vulnerable individuals may often be drawn towards drug-addiction to combat stress. This systematic review critically appraises the relationship of various genetic factors linked with the incidences of ADA development. For coherence, we focused solely on cocaine as a substance of abuse in this study. Online scholarly databases were used to screen pertinent literature using apt keywords; and the final retrieval included 42 primary-research articles. The major conclusion drawn from this systematic analysis states that there are 51 genes linked with the development of ADA; and 3 (BDNF, PERIOD2 and SLC6A4) of them are common to all the three aspects of ADA. Further, inter-connectivity analyses of the 51 genes further endorsed the central presence of BDNF and SLC6A4 genes in the development of ADA disorders. The conclusions derived from this systematic study pave the way for future studies for the identification of diagnostic biomarkers and drug targets; and for the development of novel and effective therapeutic regimens against ADA.

National assessment of anti-epileptic drug exposures among pre-teens and adolescents, 2000-2020

BACKGROUND AND OBJECTIVES

Anti-epileptic drugs (AEDs) are increasingly used to treat psychiatric conditions, exposing many children to potentially harmful medications. This includes adolescents, who are at higher risk for self-harm. The purpose of this study was to describe the epidemiology of pediatric AED poisonings and assess which AEDs are associated with more severe clinical outcomes.

METHODS

This retrospective cross-sectional analysis examined single-substance AED exposure cases in pre-teens (10-14 years) and adolescents (15-19 years) reported to the National Poison Database System (NPDS) between 2000 and 2020 (cases through 2019 were included for trend analysis due to incomplete population data). We described characteristics of ingestions by age group, including AEDs implicated.

RESULTS

There were 74,818 AED exposure cases reported to the NPDS, including 25,928 (34.7%) in pre-teens and 48,890 (65.3%) in adolescents. Among adolescents, 35,570 (72.8%) exposure cases were intentional, with 27,655 (56.6%) specifically related to a suspected suicide attempt. The most common AEDs implicated in poisonings were clonazepam (19.8%), valproic acid (15.3%), and lamotrigine (13.8%). The odds of hospitalization (adjusted odds ratio [aOR] 2.0 [95% confidence interval [CI], 2.0-2.1]), intubation (aOR 2.1 [95% CI, 1.8-2.4]), seizure (aOR 1.6 [95% CI, 1.4-1.9]), and serious outcome (aOR 1.8 [95% CI, 1.7-1.9]) were higher in the adolescent group compared to the pre-teen group. Intentional ingestions increased by a yearly rate of 2.8% (95% CI, 2.3-3.2). Intentional tiagabine exposure was associated with the greatest increased odds of serious outcome (aOR 4.7 [95% CI, 3.6-6.3]).

DISCUSSION

In this cross-sectional analysis of pediatric AED exposure cases reported to the NPDS, AED poisonings among pre-teens and adolescents increased significantly between 2000 and 2019. Of particular concern is the large increase in intentional exposure cases related to AEDs. With the population-adjusted rate of epilepsy diagnoses remaining relatively unchanged, these results may indicate that the rise in AED exposure cases may be related to increased prescribing of AEDs for psychiatric indications as opposed to epilepsy.

CONCLUSIONS

Pediatric AED poisonings reported to the NPDS are increasing, especially among adolescents engaging in intentional ingestions. These findings provide additional information for consideration in risk-benefit assessments when selecting medications for the treatment of psychiatric conditions in children.

Antiepileptic Drug Tiagabine Does Not Directly Target Key Cardiac Ion Channels Kv11.1, Nav1.5 and Cav1.2

Tiagabine is an antiepileptic drug used for the treatment of partial seizures in humans. Recently, this drug has been found useful in several non-epileptic conditions, including anxiety, chronic pain and sleep disorders. Since tachycardia-an impairment of cardiac rhythm due to cardiac ion channel dysfunction-is one of the most commonly reported non-neurological adverse effects of this drug, in the present paper we have undertaken pharmacological and numerical studies to assess a potential cardiovascular risk associated with the use of tiagabine. A chemical interaction of tiagabine with a model of human voltage-gated ion channels (VGICs) is described using the molecular docking method. The obtained in silico results imply that the adverse effects reported so far in the clinical cardiological of tiagabine could not be directly attributed to its interactions with VGICs. This is also confirmed by the results from the isolated organ studies (i.e., calcium entry blocking properties test) and in vivo (electrocardiogram study) assays of the present research. It was found that tachycardia and other tiagabine-induced cardiac complications are not due to a direct effect of this drug on ventricular depolarization and repolarization.

FDA postmarketing safety labeling changes: What have we learned since 2010 about impacts on prescribing rates, drug utilization, and treatment outcomes

PURPOSE

Prior literature reviews have identified gaps in understanding of how postmarketing safety labeling changes and related FDA communications impact key clinical and behavioral outcomes. We conducted a review of newly published studies on this topic to determine what new evidence exists and to identify which gaps may still remain. We believe that this information can support FDA as it develops and implements future risk communication approaches.

METHODS

We searched PubMed and Embase for studies published between January 1, 2010, and August 7, 2017 that examined the impact of labeling changes or associated FDA safety-related communications. For each study, we extracted information on research design and findings for key clinical outcomes and behaviors. We also conducted a ROBINS-I review to identify potential for bias in the research design of each study.

RESULTS

We found that the estimated impacts of FDA labeling changes on several key outcomes-including adverse events-varied. Labeling changes also yielded unintended consequences on drug prescribing in some cases, despite low provider adherence. Finally, some studies we reviewed exhibited potential for bias due to confounding, among other factors.

CONCLUSIONS

The new studies we reviewed contain many of the same limitations identified in previously published reviews. While there are several challenges to conducting this research there is substantial room for improvement in the quality of the evidence base. More information, particularly with respect to the types of populations and medications affected by labeling changes, is needed to support the development of more effective and targeted safety communications.

Insights into the interaction mechanism between tiagabine hydrochloride and two serum albumins

Tiagabine hydrochloride (TGB) is a widely used anticonvulsive drug for the treatment of epilepsy. To better understand the interactions of TGB with plasma proteins, human serum albumin (HSA) and bovine serum albumin (BSA) were selected as model proteins. TGB slightly increased thermal stability of the proteins as confirmed by VP-capillary differential scanning calorimetric (DSC) measurements. Isothermal titration calorimeter (ITC) results showed that TGB could be combined with HSA and BSA moderately, which was also corroborated by fluorescence analysis. Besides, the thermodynamic parameters (ΔH > 0, ΔS > 0) indicated that hydrophobic forces played a major role in the formulation of TGB-HSA and TGB-BSA complexes. Moreover, the main binding sites of TGB to HSA and BSA were also examined by classical fluorescent probe (dansylsarcosine and dansylamide) experiments, showing that TGB and dansylsarcosine competitively interacted with HSA and BSA at the same binding sites. Additionally, TGB had no obvious effect on the conformation change of HSA and BSA as indicated by spectroscopic analyses. This study provides useful information about the interaction mechanism of TGB and serum albumins, which could help to better utilize TGB in biomedical field.

Antiepileptic drugs: Role in paediatric poisoning

Intoxications, both accidental and intentional, are common in children and adolescents and often require hospitalisation and intensive treatment. Antiepileptic drugs are a possible cause of poisoning and intoxications because this category of medications has shown a rising trend in recent years. They might be responsible for multi-organ dysfunctions of variable severity, ranging from subtle symptoms to life-threatening complications. No guidelines on the management of these intoxications in the paediatric population are currently available, and treatment is mainly supportive. Activated charcoal administration and extracorporeal circulation techniques for drug removal have been proposed. Facing the complexity of this clinical scenario, it is of utmost importance to maintain a high index of suspicion to guarantee a prompt intervention and ensure the best possible management for the patient.

Potential role of selected antiepileptics used in neuropathic pain as human GABA transporter isoform 1 (GAT1) inhibitors-Molecular docking and pharmacodynamic studies

The chemical interaction of nine antiepileptic drugs (tiagabine, gabapentin, pregabalin, lamotrigine, zonisamide, valproic acid, valpromide, vigabatrin, progabide) and two endogenous metabolites (4-aminobutanoic acid, 4-hydroxybutanoic acid) with a model of human GABA transporter 1 (hGAT1) is described using the molecular docking method. To establish the role of hGAT1 in chronic pain, tiagabine, a selective hGAT1 inhibitor, was assessed in the in vivo experiments for its antiallodynic properties in two mouse models of neuropathic pain. Docking analyses performed in this study provided the complex binding energies, specific hydrogen bond components, and hydrogen bond properties such as energies, distances and angles. The data of the docking studies strongly support the assumption that the antiepileptic and analgesic actions of the studied drugs can be at least in part related to the strength of their chemical interactions with hGAT1. In vivo experiments with tiagabine confirmed the involvement of hGAT1 in the regulation of the mechanical nociceptive threshold in neuropathic pain.