Acute Hyperglycemia Associated with Short-Term Use of Atypical Antipsychotic Medications

Insulin effects on core neurotransmitter pathways involved in schizophrenia neurobiology: a meta-analysis of preclinical studies. Implications for the treatment

Impairment of insulin action and metabolic dysregulation have traditionally been associated with schizophrenia, although the molecular basis of such association remains still elusive. The present meta-analysis aims to assess the impact of insulin action manipulations (i.e., hyperinsulinemia, hypoinsulinemia, systemic or brain insulin resistance) on glutamatergic, dopaminergic, γ-aminobutyric acid (GABA)ergic, and serotonergic pathways in the central nervous system. More than one hundred outcomes, including transcript or protein levels, kinetic parameters, and other components of the neurotransmitter pathways, were collected from cultured cells, animals, or humans, and meta-analyzed by applying a random-effects model and adopting Hedges'g to compare means. Two hundred fifteen studies met the inclusion criteria, of which 180 entered the quantitative synthesis. Significant impairments in key regulators of synaptic plasticity processes were detected as the result of insulin handlings. Specifically, protein levels of N-methyl-D-aspartate receptor (NMDAR) subunits including type 2A (NR2A) (Hedges' g = -0.95, 95%C.I. = -1.50, -0.39; p = 0.001; I2 = 47.46%) and 2B (NR2B) (Hedges'g = -0.69, 95%C.I. = -1.35, -0.02; p = 0.043; I2 = 62.09%), and Postsynaptic density protein 95 (PSD-95) (Hedges'g = -0.91, 95%C.I. = -1.51, -0.32; p = 0.003; I2 = 77.81%) were found reduced in insulin-resistant animal models. Moreover, insulin-resistant animals showed significantly impaired dopamine transporter activity, whereas the dopamine D2 receptor mRNA expression (Hedges'g = 3.259; 95%C.I. = 0.497, 6.020; p = 0.021; I2 = 90.61%) increased under insulin deficiency conditions. Insulin action modulated glutamate and GABA release, as well as several enzymes involved in GABA and serotonin synthesis. These results suggest that brain neurotransmitter systems are susceptible to insulin signaling abnormalities, resembling the discrete psychotic disorders' neurobiology and possibly contributing to the development of neurobiological hallmarks of treatment-resistant schizophrenia.

A review of the bidirectional relationship between psychiatric disorders and diabetes mellitus

The prevalence of type 2 diabetes is rising worldwide, including Saudi Arabia. Among patients with diabetes, 30% suffer from mental disorders, such as depression, schizophrenia, delirium, and substance misuse (for example, tobacco smoking). Moreover, these disorders appear to share a bidirectional relationship with diabetes. For example, the incidence of diabetes has been shown to be 2-4 times greater in patients with schizophrenia than in normal individuals; also, there is a known association between depression and diabetes. In this review, we focus specifically on the bidirectional relationship between diabetes and psychiatric disorders, including the effects of antipsychotic drugs.

A high-throughput chemical-genetics screen in murine adipocytes identifies insulin-regulatory pathways

Pathways linking activation of the insulin receptor to downstream targets of insulin have traditionally been studied using a candidate gene approach. To elucidate additional pathways regulating insulin activity, we performed a forward chemical-genetics screen based on translocation of a glucose transporter 4 (Glut4) reporter expressed in murine 3T3-L1 adipocytes. To identify compounds with known targets, we screened drug-repurposing and natural product libraries. We identified, confirmed, and validated 64 activators and 65 inhibitors that acutely increase or rapidly decrease cell-surface Glut4 in adipocytes stimulated with submaximal insulin concentrations. These agents were grouped by target, chemical class, and mechanism of action. All groups contained multiple hits from a single drug class, and several comprised multiple structurally unrelated hits for a single target. Targets include the β-adrenergic and adenosine receptors. Agonists of these receptors increased and inverse agonists/antagonists decreased cell-surface Glut4 independently of insulin. Additional activators include insulin sensitizers (thiazolidinediones), insulin mimetics, dis-inhibitors (the mTORC1 inhibitor rapamycin), cardiotonic steroids (the Na⁺/K⁺-ATPase inhibitor ouabain), and corticosteroids (dexamethasone). Inhibitors include heterocyclic amines (tricyclic antidepressants) and 21 natural product supplements and herbal extracts. Mechanisms of action include effects on Glut4 trafficking, signal transduction, inhibition of protein synthesis, and dissipation of proton gradients. Two pathways that acutely regulate Glut4 translocation were discovered: de novo protein synthesis and endocytic acidification. The mechanism of action of additional classes of activators (tanshinones, dalbergiones, and coumarins) and inhibitors (flavonoids and resveratrol) remains to be determined. These tools are among the most sensitive, responsive, and reproducible insulin-activity assays described to date.

Improved Metabolic and Psychiatric Outcomes with Discontinuation of Atypical Antipsychotics in Youth Hospitalized in a State Psychiatric Facility

OBJECTIVES

To assess the impact of antipsychotic tapering and discontinuation on measures of metabolic functioning and psychiatric symptom severity in severely impaired youth hospitalized in a psychiatric state hospital.

METHODS

The study examined psychiatric and metabolic measures in 67 hospitalized children and adolescents (mean age 11.9; 56 with discontinued use of antipsychotics, 10 with continued use of antipsychotics, and 1 started on an antipsychotic) from admission to discharge.

RESULTS

Upon admission, 56 youth were tapered off of antipsychotic medications, started on other forms of pharmacotherapy (92.9% were started on medications used to treat attention-deficit/hyperactivity disorder), and received evidence-based behavioral programming and were ultimately discharged from the hospital. The mean duration of treatment was 228 days for the discontinuation group and 204 days for the continuation group. Significant decreases in body mass index [BMI; t(53) = 7.12, p = 0.0001] and BMI percentile [t(53) = 6.73, p = 0.0001] were found from admission to discharge in the antipsychotic discontinuation group. Changes in BMI, BMI percentile, or systolic blood pressure were not found in the group (n = 10) who were maintained on antipsychotics. Both groups experienced a significant increase in their Global Assessment of Functioning score [t(52) = 19.98, p = 0.0001 for discontinued; t(8) = 5.092, p = 0.001 for maintained]. Psychiatric symptom severity scores significantly improved in many subscales relevant to disruptive behaviors and mood disorders for those who were removed from the medications. For those maintained on the antipsychotics, there were fewer changes in psychiatric symptom scores.

CONCLUSION

Discontinuation of atypical antipsychotic medications in conjunction with tailoring treatment to presenting diagnoses resulted in metabolic and psychiatric symptom improvement among severely impaired state hospital inpatient youth. These results serve as a feasibility demonstration that discontinuation of antipsychotics does not provoke psychiatric destabilization, particularly among disruptive behavior disordered youth.

Melatonin for Reducing Weight Gain Following Administration of Atypical Antipsychotic Olanzapine for Adolescents with Bipolar Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVES

We aimed to evaluate melatonin effectiveness in weight gain reduction following olanzapine use for 11-17-year-old bipolar disorder patients.

EXPERIMENTAL DESIGN

Seventy-seven adolescent outpatients, subsequent to their initial diagnosis of bipolar I disorder by a psychiatrist, entered this study. After assessing inclusion and exclusion criteria, 48 patients consented to participate. Twenty-four patients were allocated to receive olanzapine, lithium carbonate, and melatonin, and 24 patients were allocated to receive olanzapine, lithium carbonate, and placebo by simple randomization. The Young Mania Rating Scale (YMRS) was performed at baseline. Before treatment and after 6 and 12 weeks of treatment, weight, height, and body mass index (BMI) were measured. Analysis of variance (ANOVA) with repeated measure and t-test were used to analyze data.

PRINCIPAL OBSERVATIONS

Nineteen patients in each group finished the study and their data were entered for analysis. Mean rise in BMI in the melatonin group compared with placebo (2.45 vs. 3.25 respectively) was marginally significant (t = 1.936; df = 36; p = 0.061). ANOVA with repeated measure also showed a marginally significant difference (F = 3.74; df = 1; p = 0.061) between groups and across time in regard to BMI. Mean body weight rise in the melatonin group compared with the placebo group (5.8 kg vs. 8.2 kg respectively) was marginally significant (t = 1.923; df = 28; p = 0.065). ANOVA with repeated measure also showed a marginally significant difference (F = 3.73; df = 1.1; p = 0.056) between groups and across time for body weight.

CONCLUSIONS

Coadministration of melatonin with olanzapine and lithium carbonate in adolescents with bipolar disorder could reduce the sharp weight gain side effect of these drugs to near significance.

Sedation/drugs used in intensive care sedation

PURPOSE OF REVIEW

There is recognition that the use of sedative drugs in critically ill patients is potentially harmful, particularly in relation to ICU delirium and clinical outcomes. In that context, there is an increasing interest in maintaining light sedation, the use of non-gamma-aminobutyric acid agonist agents and antipsychotics.

RECENT FINDINGS

The sedative drugs currently available have limitations relating to duration of action, cost or variability in response. Recent reviews and meta-analyses comparing sedatives in ICU patients differ in their findings depending on whether trials in elective cardiac surgical patients are included. Dexmedetomidine does appear to reduce the number of ventilator days in the less sick critically ill patient. There is currently no evidence to support the routine use of antipsychotics in ICU patients to prevent or treat delirium, although they will reduce agitation and they appear to be well tolerated when used in the critically ill patient. Sedation protocols and early mobilization reduce the use of sedative drugs and improve some outcomes but are challenging to implement in practice.

SUMMARY

The bedside clinician needs to balance the need to sedate the patient and maintain life-saving support, while keeping their patient responsive, cooperative and pain free.

Pharmacological treatment for generalized anxiety disorder in adults: an update

INTRODUCTION

Modest response and remission rates for the selective serotonin reuptake inhibitors and the serotonin-norepinephrine reuptake inhibitors, coupled with mounting evidence that the tolerability of the antidepressants (ADs) may have been overstated in the literature, has contributed to changes in prescribing patterns for generalized anxiety disorder (GAD). New interest in the absence of evidence that supports these standard therapies as superior to benzodiazepines stimulated a review of the literature.

AREAS COVERED

A literature search was conducted in the MedLine database with search terms 'generalized anxiety disorder' and 'treatment' for purposes of including relevant literature related to pharmacologic treatment of GAD. Aside from a review of pivotal literature, the authors also included newer studies that evaluated novel drug treatments. Last, the database was searched for benzodiazepine comparisons to standard therapy secondary to concerns that such literature is sparse. The review of newer modalities and the decision to include related literature was also based on the strength of the evidence and the status of their approval for the treatment of GAD.

EXPERT OPINION

Although ADs remain the most frequently prescribed medications for GAD, alternative and off-label therapies such as pregabalin, the atypical antipsychotics and vortioxetine are garnering interest. Based on the evidence available to us, it is our recommendation that along with the ADs, benzodiazepines be considered a possible first-line therapy in eligible patients based on the discretion and clinical judgment of the treating physician.