Pharmacokinetics and tissue distribution of olanzapine in rats

In situ-gelling hydrophobized starch nanoparticle-based nanoparticle network hydrogels for the effective delivery of intranasal olanzapine to treat brain disorders

Intranasal (IN) delivery offers potential to deliver antipsychotic drugs with improved efficacy to the brain. However, the solubilization of such drugs and the frequency of required re-application both represent challenges to its practical implementation in treating various mental illnesses including schizophrenia. Herein, we report a sprayable nanoparticle network hydrogel (NNH) consisting of hydrophobically-modified starch nanoparticles (SNPs) and mucoadhesive chitosan oligosaccharide lactate (COL) that can gel in situ within the nasal cavity and release ultra-small penetrative SNPs over time. Hydrophobization of the SNPs enables enhanced uptake and prolonged release of poorly water soluble drugs such as olanzapine from the NNH depot through mucous and ultimately into the brain via the nose-to-brain (N2B) pathway. The hydrogel shows high in vitro cytocompatibility in mouse striatal neuron and human primary nasal cell lines and in vivo efficacy in an amphetamine-induced pre-clinical rat schizophrenia model, with IN-delivered NNH hydrogels maintaining successful attenuation of locomotor activity for up to 4 h while all other tested treatments (drug-only IN or conventional intraperitoneal delivery) failed to attenuate at any time point past 0.5 h. As such, in situ-gelling NNHs represent a safe excipient for the IN delivery of hydrophobic drugs directly to the brain using customized SNPs that exhibit high penetration and drug complexing properties to maximize effective drug delivery.

In vivo deposition of poorly soluble drugs

Administered drug molecules, whether dissolved or solubilized, have the potential to precipitate and accumulate as solid forms in tissues and cells within the body. This phase transition can significantly impact the pharmacokinetics of treatment. It is thus crucial to gain an understanding of how drug solubility/permeability, drug formulations and routes of administration affect in vivo behaviors of drug deposition. This review examines literature reports on the drug deposition in tissues and cells of poorly water-soluble drugs, as well as underlying physical mechanisms that lead to precipitation. Our work particularly highlights drug deposition in macrophages and the subcellular fate of precipitated drugs. We also propose a tissue permeability-based classification framework to evaluate precipitation potentials of poorly soluble drugs in major organs and tissues. The impact on pharmacokinetics is further discussed and needs to be considered in developing drug delivery systems. Finally, bioimaging techniques that are used to examine aggregated states and the intracellular trafficking of absorbed drugs are summarized.

Potent synergistic effects of dulaglutide and food restriction in prevention of olanzapine-induced metabolic adverse effects in a rodent model

BACKGROUND

Antipsychotics are indispensable in the treatment of severe mental illneses, however adverse metabolic effects including diabetes, weight gain, dyslipidemia, and related cardiovascular morbidity are common, and current pharmacological strategies for their management are unsatisfactory. Glucagon-like 1 peptide receptor agonists (GLP-1 RAs) are approved for the treatment of type 2 diabetes and obesity hold promise for the management of antipsychotic-associated adverse metabolic effects.

METHODS

To characterize the molecular effects and identify biomarkers for GLP-1 RA preventive treatment, Sprague-Dawley female rats were treated with long-acting formulations of the antipsychotic olanzapine and the GLP-1 RA dulaglutide for 8 days. A pair-feeding protocol evaluated the combined effects of dulaglutide and food restriction on an olanzapine-induced metabolic phenotype. Body weight and food consumption were recorded. Biochemical analysis included a lipid profile, a spectrum of gastrointestinal and adipose tissue-derived hormones, and fibroblast growth factor 21 serum levels.

RESULTS

Olanzapine induced hyperphagia, weight gain, increased serum triglycerides and HDL cholesterol. Food restriction affected the OLA-induced phenotype but not serum markers. Dulaglutide led to a modest decrease in food intake, with no effect on weight gain, and did not reverse the OLA-induced changes in serum lipid parameters. Concomitant dulaglutide and food restriction resulted in weight loss, decreased feed efficiency, and lower total and HDL cholesterol.

CONCLUSIONS

A combined strategy of dulaglutide and food restriction manifested a massive synergistic benefit. GLP-1RAs represent a promising strategy and deserve thorough future research. Our findings underline the potential importance of lifestyle intervention in addition to GLP-1 RA treatment.

Olanzapine Modulate Lipid Metabolism and Adipose Tissue Accumulation via Hepatic Muscarinic M3 Receptor-Mediated Alk-Related Signaling

Olanzapine is an atypical antipsychotic drug and a potent muscarinic M3 receptor (M3R) antagonist. Olanzapine has been reported to cause metabolic disorders, including dyslipidemia. Anaplastic lymphoma kinase (Alk), a tyrosine kinase receptor well known in the pathogenesis of cancer, has been recently identified as a key gene in the regulation of thinness via the regulation of adipose tissue lipolysis. This project aimed to investigate whether Olanzapine could modulate the hepatic Alk pathway and lipid metabolism via M3R. Female rats were treated with Olanzapine and/or Cevimeline (an M3R agonist) for 9 weeks. Lipid metabolism and hepatic Alk signaling were analyzed. Nine weeks' treatment of Olanzapine caused metabolic disturbance including increased body mass index (BMI), fat mass accumulation, and abnormal lipid metabolism. Olanzapine treatment also led to an upregulation of Chrm3, Alk, and its regulator Ptprz1, and a downregulation of Lmo4, a transcriptional repressor of Alk in the liver. Moreover, there were positive correlations between Alk and Chrm3, Alk and Ptprz1, and a negative correlation between Alk and Lmo4. However, cotreatment with Cevimeline significantly reversed the lipid metabolic disturbance and adipose tissue accumulation, as well as the upregulation of the hepatic Alk signaling caused by Olanzapine. This study demonstrates evidence that Olanzapine may cause metabolic disturbance by modulating hepatic Alk signaling via M3R, which provides novel insight for modulating the hepatic Alk signaling and potential interventions for targeting metabolic disorders.

Olanzapine Effects on Parvalbumin/GAD67 Cell Numbers in Layers/Subregions of Dorsal Hippocampus of Chronically Socially Isolated Rats

Depression is linked to changes in GABAergic inhibitory neurons, especially parvalbumin (PV) interneurons, which are susceptible to redox dysregulation. Olanzapine (Olz) is an atypical antipsychotic whose mode of action remains unclear. We determined the effect of Olz on PV-positive (+) and glutamate decarboxylase 67 (GAD67) + cell numbers in the layers of dorsal hippocampus (dHIPP) cornu ammonis (CA1-CA3) and dentate gyrus (DG) subregions in rats exposed to chronic social isolation (CSIS), which is an animal model of depression. Antioxidative enzymes and proinflammatory cytokine levels were also examined. CSIS decreased the PV+ cell numbers in the Stratum Oriens (SO) and Stratum Pyramidale (SP) of dCA1 and dDG. It increased interleukin-6 (IL-6), suppressor of cytokine signaling 3 (SOCS3), and copper-zinc superoxide dismutase (CuZnSOD) levels, and it decreased catalase (CAT) protein levels. Olz in CSIS increased the number of GAD67+ cells in the SO and SP layers of dCA1 with no effect on PV+ cells. It reduced the PV+ and GAD67+ cell numbers in the Stratum Radiatum of dCA3 in CSIS. Olz antagonizes the CSIS-induced increase in CuZnSOD, CAT and SOCS3 protein levels with no effect on IL-6. Data suggest that the protective Olz effects in CSIS may be mediated by altering the number of PV+ and GAD67+ cells in dHIPP subregional layers.

Reactivation of Early-Life Stress-Sensitive Neuronal Ensembles Contributes to Lifelong Stress Hypersensitivity

Early-life stress (ELS) is one of the strongest lifetime risk factors for depression, anxiety, suicide, and other psychiatric disorders, particularly after facing additional stressful events later in life. Human and animal studies demonstrate that ELS sensitizes individuals to subsequent stress. However, the neurobiological basis of such stress sensitization remains largely unexplored. We hypothesized that ELS-induced stress sensitization would be detectable at the level of neuronal ensembles, such that cells activated by ELS would be more reactive to adult stress. To test this, we leveraged transgenic mice to genetically tag, track, and manipulate experience-activated neurons. We found that in both male and female mice, ELS-activated neurons within the nucleus accumbens (NAc), and to a lesser extent the medial prefrontal cortex, were preferentially reactivated by adult stress. To test whether reactivation of ELS-activated ensembles in the NAc contributes to stress hypersensitivity, we expressed hM4Dis receptor in control or ELS-activated neurons of pups and chemogenetically inhibited their activity during experience of adult stress. Inhibition of ELS-activated NAc neurons, but not control-tagged neurons, ameliorated social avoidance behavior following chronic social defeat stress in males. These data provide evidence that ELS-induced stress hypersensitivity is encoded at the level of corticolimbic neuronal ensembles.SIGNIFICANCE STATEMENT Early-life stress enhances sensitivity to stress later in life, yet the mechanisms of such stress sensitization are largely unknown. Here, we show that neuronal ensembles in corticolimbic brain regions remain hypersensitive to stress across the life span, and quieting these ensembles during experience of adult stress rescues stress hypersensitivity.

Intranasal administration of olanzapine has beneficial outcome in a rat activity-based anorexia model

The atypical antipsychotic drug olanzapine is prescribed despite clinical studies on olanzapine treatment showing mixed results on treatment efficacy in anorexia nervosa. We investigated the effect of systemic and intranasal administration of olanzapine in the activity-based anorexia (ABA) model. Rats were habituated to a running wheel and exposed to the ABA model while treated with olanzapine. During ABA rats had 1.5 h of daily access to food and ad libitum access to a running wheel for seven consecutive days. Olanzapine was administered via an osmotic minipump (1, 2.75, and 7.5 mg/kg) or intranasally 2 h before dark onset (1 and 2.75 mg/kg). We monitored body weight, food intake, wheel revolutions, body temperature, and adipose tissue. We found 2.75 and 7.5 mg/kg systemic olanzapine decreased wheel revolutions during ABA. Relative adipose tissue mass was increased in the 7.5 mg/kg olanzapine-treated group while body weight, food intake, and body temperature were unaltered by the systemic olanzapine. 1 and 2.75 mg/kg intranasal olanzapine diminished wheel revolutions and body temperature during the first 2 h after administration. The intranasal olanzapine-treated rats had a higher body weight at the end of ABA. We find that olanzapine has beneficial outcomes in the ABA via two administration routes by acting mainly on running wheel activity. Intranasal olanzapine showed a rapid effect in the first hours after administration in reducing locomotor activity. We recommend further exploring intranasal administration of olanzapine in anorectic patients to assist them in coping with restlessness.

The long-lasting effects of early antipsychotic exposure during juvenile period on adult behaviours - A study in a poly I:C rat model

Second generation antipsychotic drugs including aripiprazole, olanzapine and risperidone are prescribed increasingly (mostly off-label) to treat various mental disorders in children and adolescents. Early treatment with antipsychotics during this period may have long-lasting behavioural impacts, but to date there have been only limited investigations. Maternal infection could be implicated in the aetiology of various mental disorders including schizophrenia. Exposure of pregnant rodents to polyriboinosinic-polyribocytidylic acid (Poly I:C) causes schizophrenia-like behavioural abnormalities and neurodevelopmental conditions such as autism spectrum disorders in offspring. This study, using a Poly I:C rat model, investigated the long-lasting effects of early aripiprazole, olanzapine and risperidone treatment in the childhood/adolescent period (postnatal day 22-50) on adult behaviours of male rats. The study showed that early treatment with three antipsychotics had different effects on long-term behavioural changes in adults. Prenatal Poly I:C exposure (5 mg/kg) at gestation day 15 caused deficits in pre-pulse inhibition and social interaction, as well as cognitive impairments, that could be partially improved by early antipsychotic treatment in the juvenile period. Early antipsychotic treatment during the childhood-adolescent period resulted in similar long-lasting effects on pre-pulse inhibition, anxiety- and depressive-related behaviours in both Poly I:C and healthy (control) male rats. Overall, these results suggest that both prenatal Poly I:C exposure and early antipsychotic treatment in the childhood/adolescent period had long-lasting effects on adult behaviours of male rats, while early antipsychotic treatment could partly prevent the onset of behavioural abnormalities resulting from prenatal insult.

Cevimeline co-treatment attenuates olanzapine-induced metabolic disorders via modulating hepatic M3 muscarinic receptor: AMPKα signalling pathway in female rats

BACKGROUND

Olanzapine is one of the most commonly used antipsychotic drugs; however, its metabolic disorders are the main obstacle in the clinic. Olanzapine is a potent antagonist of the M3 acetylcholine muscarinic receptor (M3R), while the downregulated hepatic M3R-AMPKα signalling pathway is involved in metabolic disorders.

AIM

This study investigated the effects of chronic co-treatment with cevimeline (an agonist of M3Rs) in attenuating olanzapine-induced metabolic disorders and the underlying mechanisms.

METHODS

Forty-eight adult female Sprague-Dawley rats were treated orally with olanzapine (2 mg/kg, 3 times/day (t.i.d.)) and/or cevimeline (9 mg/kg, t.i.d.), or control (vehicle) for 9 weeks.

RESULTS

Cevimeline co-treatment significantly attenuated olanzapine-induced body weight gain and glucolipid metabolic disorders. Importantly, cevimeline co-treatment attenuated olanzapine-induced upregulation of M3Rs, while the co-treatment improved olanzapine-induced downregulation of AMPKα in the liver. Cevimeline co-treatment attenuated olanzapine-induced dyslipidaemia by modulating the hepatic M3R-AMPKα downstream pathways. Cevimeline co-treatment also improved lower activated AKT-GSK3β signalling to reverse impairment of glucose metabolism and insulin resistance caused by chronic olanzapine treatment.

CONCLUSION

These results not only support the important role of M3R antagonism and its related AMPKα and downstream pathways in antipsychotic-induced metabolic disorders but also indicate that these pathways might be promising targets for pharmacological intervention to control these side effects caused by antipsychotic therapy.

Entry of the antipsychotic drug, olanzapine, into the developing rat brain in mono- and combination therapies

Background: Olanzapine is used to treat schizophrenia and bipolar disorder in women of childbearing age. Continuation of psychotropic medications throughout pregnancy and lactation is often required as cessation could be dangerous for both mother and child. However, there is a lack of information on the transfer of these drugs into the developing brain. Methods: Sprague Dawley rats at three developmental ages: embryonic day E19, postnatal day P4 and non-pregnant adult females were administered unlabelled or radiolabelled ( ³H) olanzapine (0.15 mg/kg) either as monotherapy or in combination with each of seven other common medications. Similar injections were administered to pregnant E19 females to investigate placental transfer. Olanzapine in plasma, cerebrospinal fluid (CSF) and brain was measured by liquid scintillation counting after a single dose (acute) or following 5 days of treatment (prolonged). Results: Olanzapine entry into brain and CSF was not age-dependent. Prolonged olanzapine treatment reduced placental transfer from 53% to 46% (p<0.05). Co-administration of digoxin or lamotrigine with olanzapine increased its entry into the fetal brain, whereas paracetamol decreased its entry into the CSF. Placental transfer of olanzapine was increased by co-treatment with cimetidine and digoxin, whereas co-treatment with lamotrigine, paracetamol or valproate led to a substantial decrease. Repeated co-treatment of digoxin and olanzapine increased olanzapine transfer into the brain and CSF, but not across the placenta. Overall entry of olanzapine from maternally administered drugs into the fetal brain was higher after combination therapy with cimetidine and digoxin. Conclusions: Co-administration of olanzapine with some commonly used drugs affected its entry into the fetus and its developing brain to a greater extent than in adults. It appears that protection of the fetal brain for these drugs primarily comes from the placenta rather than from the fetal brain barriers. Results suggest that drug combinations should be used with caution particularly during pregnancy.

Hepatoprotective effect of trypsin/chymotrypsin against olanzapine-induced non-alcoholic steatohepatitis in rats

Metabolic side effects of atypical antipsychotics are an important cause of deterioration of cognitive function and failure of drug adherence. The antifatty effect trypsin/chymotrypsin (T/C) and their mechanisms of action remain unclear. To investigate possible therapeutic effect of T/C in rat model of chronic olanzapine (OLZ) - induced hepatic steatosis. Twenty rats were divided into two groups: control (C), given distilled water, and O, given 1 mg/kg of OLZ orally daily for 7 weeks. Then, both groups were given T/C 3 enzyme activity unit (EAU)/kg orally as an add-on treatment daily for the next 5 weeks and were named T/C or T/C+O groups. Rat performance in radial arm water maze was tested twice before and after T/C treatment. We measured liver enzymes, alpha-1 antitrypsin, albumin, total protein, direct and total bilirubin, inflammatory cytokines, and lipoprotein serum levels. Liver samples were collected for histopathology and Ki67 expression. The T/C add-on caused significant reduction in OLZ-induced elevation of alanine transaminase (ALT; P < 0.01), aspartate transaminase (AST; P < 0.001), alkaline phosphatase (ALP; P < 0.05), total cholesterol (Tc; P < 0.01), low-density lipoproteins (LDL-c; P < 0.05), steatosis score (P < 0.001), hepatocyte necrosis (P < 0.01), and significantly increased Ki67 expression (P < 0.01). The T/C add-on to OLZ provided protection against hepatic steatosis, elevated enzymes, and disturbed lipid profile and increased Ki67 without disturbing memory function.

Modulatory effect of olanzapine on SMIM20/phoenixin, NPQ/spexin and NUCB2/nesfatin-1 gene expressions in the rat brainstem

Background

Phoenixin, spexin and nesfatin-1 belong to a family of newly discovered multifunctional neuropeptides that play regulatory roles in several brain structures and modulate the activity of important neural networks. However, little is known about their expression and action at the level of brainstem. The present work was, therefore, focused on gene expression of the aforementioned peptides in the brainstem of rats chronically treated with olanzapine, a second generation antipsychotic drug.

Methods

Studies were carried out on adult, male Sprague–Dawley rats that were divided into 2 groups: control and experimental animals treated with olanzapine (28-day-long intraperitoneal injection, at dose 5 mg/kg daily). All individuals were killed under anesthesia and the brainstem excised. Total mRNA was isolated from homogenized samples of both structures and the RT-PCR method was used for estimation of related SMIM20/phoenixin, NPQ/spexin and NUCB2/nesfatin-1 gene expression.

Results

Long-term treatment with olanzapine is reflected in qualitatively different changes in expression of examined neuropeptides mRNA in the rat brainstem. Olanzapine significantly decreased NPQ/spexin mRNA expression, but increased SMIM20/phoenixin mRNA level in the rat brainstem; while NUCB2/nesfatin-1 mRNA expression remained unchanged.

Conclusions

Olanzapine can affect novel peptidergic signaling in the rat brainstem. This may cautiously suggest the presence of an alternative mode of its action.

Assessment of brain-to-blood drug distribution using liquid chromatography

Delivery of already existing and new drugs under development to the brain necessitates passage across the blood-brain barrier (BBB) with its tight intercellular junctions, molecular components and transporter systems. Consequently, it is critical to identify the extent of brain permeation and the partitioning across the BBB. The interpretation of brain-to-blood ratios is considered to be a significant and fundamental approach for estimating drug penetration through BBB, the brain-targeting ability and central nervous system (CNS) pharmacokinetics. Among the different bioanalytical techniques, liquid chromatography with various detectors has been widely used for determination of these ratios. This review defines the different approaches for sample preparation, extraction techniques and liquid chromatography procedures concerned with the determination of drugs in blood and brain tissues and the assessment of brain-to-blood levels. These approaches are expanded to cover the analysis of several drug classes such as CNS-acting drugs, chemotherapeutics, antidiabetics, herbal medicinal products, radiopharmaceuticals, antibiotics and antivirals. Accordingly, stability in biological matrices and matrix effects are investigated. The different administration/formulation effects and the possible deviations in these ratios are also disscussed.

Interaction between olanzapine and human serum albumin and effect of metal ions, caffeine and flavonoids on the binding: A spectroscopic study

In this study, the binding of olanzapine (OLZ) to human serum albumin (HSA) and the influence of metal ions (Ca²⁺, Mg²⁺, Cu²⁺, Zn²⁺, Fe³⁺), caffeine (CAF) and flavonoids (diosmin (DIO), catechin (CAT), quercetin (QUE)), on their affinity, was investigated by fluorescence spectroscopy and UV-vis absorption spectroscopy. Fluorescence experiments suggest that OLZ quench the fluorescence of HSA through the mixed quenching mechanism and non-radiation energy transferring as a result of the HSA-OLZ complex formation. OLZ spontaneously bind in the site I on HSA, and according to thermodynamic parameters, the reaction was spontaneous and mainly driven by hydrogen bonds and van der Waals interactions. The presence of Mⁿ⁺ ions, CAF, DIO and CAT decreased binding affinity between OLZ and HSA which indicates that they could compete against OLZ in the site I. Contrary, in the presence of QUE the binding affinity of the HSA-OLZ system enhanced, which may be explained by conformational changes in HSA (non-competitive interference).

Human macrophages stimulate expression of inflammatory mediators in adipocytes; effects of second-generation antipsychotics and glucocorticoids on cellular cross-talk

OBJECTIVE

Adipose tissue inflammation and distorted macrophage-adipocyte communication are positively associated with metabolic disturbances. Some pharmacological agents, such as second-generation antipsychotics (SGAs) and synthetic glucocorticoid (GC) dexamethasone, tend to induce adverse metabolic side effects and the underlying mechanisms are not fully understood. Our work aimed to study whether SGAs and dexamethasone affect macrophage phenotype and macrophage-adipocyte communication on gene expression level. We selected the model involving THP-1-derived macrophages, polarized into M0, M1, and M2 phenotypes, and primary human mature subcutaneous adipocytes.

METHODS

Abdominal subcutaneous adipose tissue needle biopsies were obtained from 6 healthy subjects (4F/2M; age: 22-64 yr; BMI: 21.7-27.6 kg/m2) followed by isolation of mature adipocytes. THP-1-human monocytic cell line was used for the study. THP-1 monocytes were differentiated and polarized into M0 (naïve), M1 (classically activated), and M2 (alternatively activated) macrophages. During and after polarization the macrophages were treated for 24 h without (control) or with therapeutic and supra-therapeutic concentrations of olanzapine (0.2 µM and 2.0 µM), aripiprazole (1.0 µM and 10 µM) and its active metabolite dehydroaripiprazole (0.4 µM and 4.0 µM). Isolated mature human adipocytes were co-incubated with THP-1-derived polarized macrophages pre-treated with SGAs after their polarization. Adipocytes and macrophages were collected before and after co-culture for mRNA expression analysis of genes involved in inflammation.

RESULTS

Co-incubation of mature human adipocytes with human macrophages, regardless of polarization, resulted in a marked induction of pro-inflammatory cytokines in adipocytes, including IL1B, IL6, TNFA, and IL10. Remarkably, it did not affect the expression of adipokines and genes involved in the regulation of energy, lipid, and glucose metabolism in adipocytes. Dexamethasone markedly reduced gene expression of pro-inflammatory cytokines in macrophages and prevented macrophage-induced inflammatory response in adipocytes. In contrast, SGAs did not affect macrophage-adipocyte communication and had a minute anti-inflammatory effect in macrophages at supra-therapeutic concentrations. Interestingly, the adipocytes co-incubated with M1 macrophages pre-treated with dexamethasone and SGAs particularly the supra-therapeutic concentration of olanzapine, reduced expression of LPL, LIPE, AKT1, and SLC2A4, suggesting that the expression of metabolic genes in adipocytes was dependent on the presence of pro-inflammatory M1 macrophages.

CONCLUSION

Together, these data suggest that macrophages induce expression of pro-inflammatory genes in human subcutaneous adipocytes without affecting the expression of adipokines or genes involved in energy regulation. Furthermore, our findings demonstrated that SGAs and dexamethasone had a mild effect on macrophage-adipocyte communication in M1 macrophage phenotype.

Effect of liraglutide on neural and peripheral markers of metabolic function during antipsychotic treatment in rats

BACKGROUND

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that prevents metabolic side effects of the antipsychotic drugs (APDs) olanzapine and clozapine through unknown mechanisms.

AIM

This study aimed to investigate the effect of chronic APD and liraglutide co-treatment on key neural and peripheral metabolic signals, and acute liraglutide co-treatment on clozapine-induced hyperglycaemia.

METHODS

In study 1, rats were administered olanzapine (2 mg/kg), clozapine (12 mg/kg), liraglutide (0.2 mg/kg), olanzapine + liraglutide co-treatment, clozapine + liraglutide co-treatment or vehicle for six weeks. Feeding efficiency was examined weekly. Examination of brain tissue (dorsal vagal complex (DVC) and mediobasal hypothalamus (MBH)), plasma metabolic hormones and peripheral (liver and kidney) cellular metabolism and oxidative stress was conducted. In study 2, rats were administered a single dose of clozapine (12 mg/kg), liraglutide (0.4 mg/kg), clozapine + liraglutide co-treatment or vehicle. Glucose tolerance and plasma hormone levels were assessed.

RESULTS

Liraglutide co-treatment prevented the time-dependent increase in feeding efficiency caused by olanzapine, which plateaued by six weeks. There was no effect of chronic treatment on melanocortinergic, GABAergic, glutamatergic or endocannabionoid markers in the MBH or DVC. Peripheral hormones and cellular metabolic markers were unaltered by chronic APD treatment. Acute liraglutide co-treatment was unable to prevent clozapine-induced hyperglycaemia, but it did alter catecholamine levels.

CONCLUSION

The unexpected lack of change to central and peripheral markers following chronic treatment, despite the presence of weight gain, may reflect adaptive mechanisms. Further studies examining alterations across different time points are required to continue to elucidate the mechanisms underlying the benefits of liraglutide on APD-induced metabolic side effects.

The protein kinase D1-mediated inflammatory pathway is involved in olanzapine-induced impairment of skeletal muscle insulin signaling in rats

AIMS

Skeletal muscle insulin resistance (SMIR) contributes to the metabolic syndrome. Mounting evidence has demonstrated that the second generation antipsychotic olanzapine causes SMIR. The present study sought to investigate the molecular mechanisms underlying olanzapine-induced SMIR.

MAIN METHODS

Male rats were given olanzapine (5 mg/kg, by a gavage method) for consecutive eight weeks. Plasma glucose and insulin concentrations were determined enzymatically or by ELISA. Gene/protein expression was analyzed by Real-Time PCR, Western blot and/or immunohistochemistry.

KEY FINDINGS

Olanzapine increased fasting plasma insulin concentration, and decreased glucose clearance during insulin tolerance test in rats. In skeletal muscle, it decreased protein expression of membrane glucose transporter (GLUT) 4, the ratio of membrane to total GLUT4, and total insulin receptor substrate 1 (IRS1). However, it increased protein phosphorylation of Ser³⁰⁷ in IRS1, Y⁶⁰⁷ in phosphoinositide 3-kinase p85α and Ser³⁰⁷ in AKT. These results indicate olanzapine-induced impairment of skeletal muscle insulin signaling. Mechanistically, olanzapine upregulated mRNA expression of TNFα, IL6 and IL1β, and protein phosphorylation of both IκB kinase (IKK)α/β and nuclear factor (NF)κB p65. Furthermore, it increased protein phosphorylation of Ser^485/491 in AMPKα2, whereas it decreased AMPKα2 activity. More importantly, both Western blot and immunohistochemical analyses revealed that olanzapine increased protein phosphorylation of Ser^744/748 in protein kinase D1 (PKD1).

SIGNIFICANCE

The present results suggest that the PKD1-mediated inflammatory pathway is involved in olanzapine-induced impairment of skeletal muscle insulin signaling in rats. Our findings may go new insight into the mechanisms underlying olanzapine-induced SMIR.

Clozapine Induced Disturbances in Hepatic Glucose Metabolism: The Potential Role of PGRMC1 Signaling

Newly emerging evidence has implicated that progesterone receptor component 1 (PGRMC1) plays a novel role not only in the lipid disturbance induced by atypical antipsychotic drugs (AAPD) but also in the deterioration of glucose homoeostasis induced by clozapine (CLZ) treatment. The present study aimed to investigate the role of PGRMC1 signaling on hepatic gluconeogenesis and glycogenesis in male rats following CLZ treatment (20 mg/kg daily for 4 weeks). Recombinant adeno-associated viruses (AAV) were constructed for the knockdown or overexpression of hepatic PGRMC1. Meanwhile, AG205, the specific inhibitor of PGRMC1 was also used for functional validation of PGRMC1. Hepatic protein expressions were measured by western blotting. Meanwhile, plasma glucose, insulin and glucagon, HbA1c and hepatic glycogen were also determined by assay kits. Additionally, concentrations of progesterone (PROG) in plasma, liver and adrenal gland were measured by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Our study demonstrated that CLZ promoted the process of gluconeogenesis and repressed glycogenesis, respectively mediated by PI3K-Akt-FOXO1 and GSK3β signaling via inhibition of PGRMC1-EGFR/GLP1R in rat liver, along with an increase in fasting blood glucose, HbA1c levels and a decrease in insulin and hepatic glycogen levels. Furthermore, through PGRMC1-EGFR/GLP1R-PI3K-Akt pathway, knockdown or inhibition (by AG205) of PGRMC1 mimics, whereas its overexpression moderately alleviates CLZ-induced glucose disturbances. Potentially, the PGRMC1 target may be regarded as a novel therapeutic strategy for AAPD-induced hepatic glucose metabolism disorder.

Peripheral mechanisms of acute olanzapine induced metabolic dysfunction: A review of in vivo models and treatment approaches

Antipsychotic (AP) medications are associated with an increased risk for developing metabolic side effects including weight gain, dyslipidemia, hypertension, type 2 diabetes (T2D), and cardiovascular disease. Previous reviews have focused on the chronic metabolic side effects associated with AP use. However, an underappreciated aspect of APs are the rapid perturbations in glucose and lipid metabolism that occur with each dose of drug. The purpose of this narrative review is to summarize work examining the peripheral mechanisms of acute olanzapine-induced related metabolic disturbances. We also discuss recent studies that have attempted to elucidate treatment approaches to mitigate AP-induced impairments in fuel metabolism.

Antipsychotic olanzapine-induced misfolding of proinsulin in the endoplasmic reticulum accounts for atypical development of diabetes

Second-generation antipsychotics are widely used to medicate patients with schizophrenia, but may cause metabolic side effects such as diabetes, which has been considered to result from obesity-associated insulin resistance. Olanzapine is particularly well known for this effect. However, clinical studies have suggested that olanzapine-induced hyperglycemia in certain patients cannot be explained by such a generalized mechanism. Here, we focused on the effects of olanzapine on insulin biosynthesis and secretion by mouse insulinoma MIN6 cells. Olanzapine reduced maturation of proinsulin, and thereby inhibited secretion of insulin; and specifically shifted the primary localization of proinsulin from insulin granules to the endoplasmic reticulum. This was due to olanzapine's impairment of proper disulfide bond formation in proinsulin, although direct targets of olanzapine remain undetermined. Olanzapine-induced proinsulin misfolding and subsequent decrease also occurred at the mouse level. This mechanism of olanzapine-induced β-cell dysfunction should be considered, together with weight gain, when patients are administered olanzapine.

N-acetylcysteine prevents olanzapine-induced oxidative stress in mHypoA-59 hypothalamic neurons

Olanzapine is a second-generation antipsychotic (AP) drug commonly prescribed for the treatment of schizophrenia. Recently, olanzapine has been found to cause brain tissue volume loss in rodent and primate studies; however, the underlying mechanism remains unknown. Abnormal autophagy and oxidative stress have been implicated to have a role in AP-induced neurodegeneration, while N-acetylcysteine (NAC) is a potent antioxidant, shown to be beneficial in the treatment of schizophrenia. Here, we investigate the role of olanzapine and NAC on cell viability, oxidative stress, mitochondrial mass and mitophagy in hypothalamic cells. Firstly, cell viability was assessed in mHypoA-59 and mHypoA NPY/GFP cells using an MTS assay and flow cytometric analyses. Olanzapine treated mHypoA-59 cells were then assessed for mitophagy markers and oxidative stress; including quantification of lysosomes, autophagosomes, LC3B-II, p62, superoxide anion (O₂^–) and mitochondrial mass. NAC (10 mM) was used to reverse the effects of olanzapine (100 µM) on O₂⁻, mitochondrial mass and LC3B-II. We found that olanzapine significantly impacted cell viability in mHypoA-59 hypothalamic cells in a dose and time-dependent manner. Olanzapine inhibited mitophagy, instigated oxidative stress and prompted mitochondrial abnormalities. NAC was able to mitigate olanzapine-induced effects. These findings suggest that high doses of olanzapine may cause neurotoxicity of hypothalamic neurons via increased production of reactive oxygen species (ROS), mitochondrial damage and mitophagy inhibition. This could in part explain data suggesting that APs may reduce brain volume.

Estimation of a preliminary therapeutic reference range for children and adolescents with tic disorders treated with tiapride

Purpose

Tiapride is commonly used in Europe for the treatment of tics. The aim of this study was to examine the relationship between dose and serum concentrations of tiapride and potential influential pharmacokinetic factors in children and adolescents. In addition, a preliminary therapeutic reference range for children and adolescents with tics treated with tiapride was calculated.

Methods

Children and adolescents treated with tiapride at three university hospitals and two departments of child and adolescents psychiatry in Germany and Austria were included in the study. Patient characteristics, doses, serum concentrations, and therapeutic outcome were assessed during clinical routine care using standardised measures.

Results

In the 49 paediatric patients (83.7% male, mean age = 12.5 years), a positive correlation was found between tiapride dose (median 6.9 mg/kg, range 0.97–19.35) and serum concentration with marked inter-individual variability. The variation in dose explained 57% of the inter-patient variability in tiapride serum concentrations; age, gender, and concomitant medication did not contribute to the variability. The symptoms improved in 83.3% of the patients. 27.1% of the patients had mild or moderate ADRs. No patient suffered from severe ADRs.

Conclusions

This study shows that tiapride treatment was effective and safe in most patients with tics. Compared with the therapeutic concentration range established for adults with Chorea Huntington, our data hinted at a lower lower limit (560 ng/ml) and similar upper limit (2000 ng/ml).

Aripiprazole Cytotoxicity Coincides with Activation of the Unfolded Protein Response in Human Hepatic Cells

Schizophrenia is a mental disease that results in decreased life expectancy and well-being by promoting obesity and sedentary lifestyles. Schizophrenia is treated by antipsychotic drugs. Although the second-generation antipsychotics (SGA), Olanzapine and Aripiprazole, are more effective in treating schizophrenia, they display a higher risk of metabolic side effects, mostly by development of diabetes and insulin resistance, weight gain, and dyslipidemia. Endoplasmic reticulum (ER) stress is induced when ER homeostasis of lipid biosynthesis and protein folding is impaired. This leads to the activation of the unfolded protein response (UPR), a signaling cascade that aims to restore ER homeostasis or initiate cell death. Chronic conditions of ER stress in the liver are associated with diabetes and perturbed lipid metabolism. These metabolic dysfunctions resemble the pharmacological side effects of SGAs. We therefore investigated whether SGAs promote the UPR in human and mouse hepatocytes. We observed full-fledged activation of ER stress by Aripiprazole not by Olanzapine. This occurred at low micromolar concentrations and to variable intensities in different cell types, such as hepatocellular carcinoma, melanoma, and glioblastoma. Mechanistically, Aripiprazole caused depletion of ER calcium, leading to activation of inositol-requiring enzyme 1 (IRE1)and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), two major transducers of the UPR. Cells underwent apoptosis with Aripiprazole treatment, which coincided with UPR induction, and this effect was reduced by adding glutathione without affecting UPR itself. Deletion of IRE1 from HepG2, a human liver cancer cell line, protected cells from Aripiprazole toxicity. Our study reveals for the first time a cytotoxic effect of Aripiprazole that involves the induction of ER stress. SIGNIFICANCE STATEMENT: The antischizophrenic drug Aripiprazole exerts cytotoxic properties at high concentrations. This study shows that this cytotoxicity is associated with the induction of endoplasmic reticulum (ER) stress and IRE1 activation, mechanisms involved in diet-induced obesity. Aripiprazole induced ER stress and calcium mobilization from the ER in human and mouse hepatocytes. Our study highlights a new mechanism of Aripiprazole that is not related to its effect on dopamine signaling.

Dual Fluorescence-colorimetric Silver Nanoparticles Based Sensor for Determination of Olanzapine: Analysis in Rat Plasma and Pharmaceuticals

The present work describes a dual-readout assay for the determination of an antipsychotic drug olanzapine using Rhodamine B modified silver nanoparticles (AgNPs). AgNPs, when mixed with Rhodamine B, quenched its fluorescence emission with high quenching efficiency as evident from the Stern Volmer plot. Transmission electron microscopy image and Dynamic Light Scattering histogram of Rhodamine B bound AgNPs showed a stable monodispersed nanosuspension. Addition of olanzapine to Rhodamine B-bound AgNPs resulted in reappearance of fluorescence, which was dependent on the amount of olanzapine added to the system. Besides displacing the surface bound Rhodamine B molecules, it caused aggregation of AgNPs which formed the basis of dual-readout sensor. Several parameters such as pH, reaction time and order of addition of the three components which may influence the analytical signal were studied and optimized. The method was validated for linearity, sensitivity, selectivity, accuracy, precision and recovery. Based on this dual-readout system, linear concentration range was established from 0.05 to 10 µM (fluorescence measurement) and 5.0 to 50 µM (colorimetric response) for olanzapine. The limit of detection (LOD) using fluorescence and colorimetric approach was 0.013 µM and 1.25 µM, respectively. The proposed method showed excellent selectivity for olanzapine in presence of several antipsychotic drugs, cations, sugars and amino acids. Finally, the method was successfully applied to a pharmacokinetic study of olanzapine in rats and also for analyzing pharmaceutical formulations.

Opipramol Inhibits Lipolysis in Human Adipocytes without Altering Glucose Uptake and Differently from Antipsychotic and Antidepressant Drugs with Adverse Effects on Body Weight Control

Treatment with several antipsychotic drugs exhibits a tendency to induce weight gain and diabetic complications. The proposed mechanisms by which the atypical antipsychotic drug olanzapine increases body weight include central dysregulations leading to hyperphagia and direct peripheral impairment of fat cell lipolysis. Several investigations have reproduced in vitro direct actions of antipsychotics on rodent adipocytes, cultured preadipocytes, or human adipose tissue-derived stem cells. However, to our knowledge, no such direct action has been described in human mature adipocytes. The aim of the present study was to compare in human adipocytes the putative direct alterations of lipolysis by antipsychotics (haloperidol, olanzapine, ziprazidone, risperidone), antidepressants (pargyline, phenelzine), or anxiolytics (opipramol). Lipolytic responses to the tested drugs, and to recognized lipolytic (e.g., isoprenaline) or antilipolytic agents (e.g., insulin) were determined, together with glucose transport and amine oxidase activities in abdominal subcutaneous adipocytes from individuals undergoing plastic surgery. None of the tested drugs were lipolytic. Surprisingly, only opipramol exhibited substantial antilipolytic properties in the micromolar to millimolar range. An opipramol antilipolytic effect was evident against isoprenaline-, forskolin-, or atrial natriuretic peptide-stimulated lipolysis. Opipramol did not impair insulin activation of glucose transport but inhibited monoamine oxidase (MAO) activity to the same extent as antidepressants recognized as MAO inhibitors (pargyline, harmine, or phenelzine), whereas antipsychotics were inefficient. Considering its unique properties, opipramol, which is not associated with weight gain in treated patients, is a good candidate for drug repurposing because it limits exaggerated lipolysis, prevents hydrogen peroxide release by amine oxidases in adipocytes, and is thereby of potential use to limit lipotoxicity and oxidative stress, two deleterious complications of diabetes and obesity.

The dosage-dependent effects of cevimeline in preventing olanzapine-induced metabolic side-effects in female rats

Olanzapine has been used for the treatment of schizophrenia and other mental disorders. However, it is associated with serious weight gain and other metabolic side-effects. The antagonistic affinity of olanzapine to muscarinic M3 receptors has been evidenced as one of the main contributors for its weight gain and other metabolic side-effects. Therefore, this study investigated whether the co-treatment of cevimeline (a M3 receptor agonist) could prevent the metabolic side-effects associated with olanzapine medication. Female Sprague Dawley rats were treated orally with olanzapine (2 mg/kg, t.i.d.) and/or cevimeline at 3 dosages (3, 6, 9 mg/kg, t.i.d.), or vehicle for two weeks. Weight gain and food/water intake were measured throughout the drug treatment period. Intraperitoneal glucose tolerance tests and open field tests were conducted. Olanzapine-treated rats demonstrated significantly elevated body weight gain, food intake, feeding efficiency, total white fat mass, liver mass, and plasma triglyceride levels, which could be partly reversed by the co-treatment with cevimeline in a dosage-dependent manner. In general, the body weight gain can only be reversed by the co-treatment of 9 mg/kg cevimeline. The cevimeline co-treatment decreased plasma triglyceride and glucose levels compared with olanzapine only treatment. The results suggested a dosage-dependent effect of cevimeline in ameliorating olanzapine-induced weight gain and metabolic side-effects, which supports further clinical trials using cevimeline to control weight gain and metabolic side-effects caused by antipsychotic medications.

Effects of second-generation antipsychotics on human subcutaneous adipose tissue metabolism

OBJECTIVE

Metabolic syndrome is prevalent in up to 50% of schizophrenia patients, which reduces their quality of life and their compliance with the treatment. It is unclear whether metabolic adverse effects of these agents are due to their direct effect on insulin-sensitive tissues or are secondary to increased adiposity. The study aimed to investigate the direct effects of the second-generation antipsychotics olanzapine and aripiprazole on human subcutaneous adipose tissue and isolated adipocyte metabolism.

METHODS

Abdominal subcutaneous adipose tissue needle biopsies were taken from 72 healthy subjects (49 F/23 M; age: 19-78 yr; BMI: 20.0-35.6 kg/m²). Isolated adipocytes or adipose tissue were respectively pre-incubated short- (30 min) and long-term (24 h, 72 h) with or without olanzapine (0.004 μM - 20 μM) and aripiprazole (0.002 μM - 100 μM). Pre-incubated adipose tissue was then snap-frozen for mRNA expression analysis of adipokines genes and genes involved in inflammation, adipogenesis, and mitochondrial function. Isolated adipocytes were used to measure basal and insulin-stimulated glucose uptake and lipolysis.

RESULTS

Acute treatment with a therapeutic concentration of olanzapine decreases basal lipolysis in isolated adipocytes; this effect was not observed after long-term incubation with the drug. Supra-therapeutic concentration of aripiprazole reduced basal and insulin-stimulated glucose uptake after short- and long-term pre-incubation. Both drugs at supra-therapeutic concentrations downregulated the expression of the pro-inflammatory cytokines IL6 and IL1B genes after 72 h incubation. Similarly, supra-therapeutic concentrations of both drugs and therapeutic concentration of olanzapine, reduced the expression of PPARGC1A, PDK4, and CPT1B genes involved in the regulation of mitochondrial functions. Neither of the antipsychotics affected the expression of the main adipokines LEP and ADIPOQ, genes involved in the regulation of lipid metabolism, LPL and FASN, nor the master adipogenesis regulator, PPARG.

CONCLUSION

Therapheutic concentrations of olanzapine and aripiprazole have a moderate direct effect on adipocyte lipid and glucose metabolism, respectively. At supra-therapeutic concentrations, both of the antipsychotics seem to act as anti-inflammatory agents and mildly suppressed genes involved in the regulation of mitochondrial functions, which could potentially contribute to metabolic adverse effects. Alternatively, second-generation antipsychotics could induce metabolic side effects via acting on other insulin-sensitive tissues and central nervous system.

Direct effects of antipsychotic drugs on insulin, energy sensing and inflammatory pathways in hypothalamic mouse neurons

INTRODUCTION

Second-generation antipsychotics cause serious metabolic side effects, but the mechanisms behind these effects remain largely unknown. However, emerging evidence supports that antipsychotics may act upon the hypothalamus, the primary brain region understood to regulate energy homeostasis. We have recently reported that the antipsychotics olanzapine, clozapine, and aripiprazole can directly act on hypothalamic rat neurons (rHypoE-19) to impair insulin, energy sensing, and modulate inflammatory pathways. In the current paper, we sought to replicate these findings to a mouse neuronal model.

METHODS

The mouse hypothalamic neuronal cell line, mHypoE-46, was treated with olanzapine, clozapine, or aripiprazole. Western blots were used to measure the energy sensing protein AMPK, components of the insulin signalling pathway (AKT, GSK3β), and components of the MAPK pathway (ERK1/2, JNK, p38), the latter linked to inflammation. RT-qPCR was used to measure mRNA expression of the inflammatory mediators IL-6, IL-10, and BDNF, well as putative receptors in the mHypoE-46 (current) and the rHypoE-19 (previously studied) cell lines.

RESULTS

In the mHypoE-46 neurons, olanzapine and aripiprazole increased AMPK phosphorylation, while clozapine and aripiprazole inhibited insulin-induced phosphorylation of AKT. Clozapine increased JNK and aripiprazole decreased ERK1/2 phosphorylation. Olanzapine also decreased IL-6 mRNA expression, while olanzapine and clozapine increased IL-10 mRNA expression. The rHypoE-19 neurons expressed the H₁, 5 H T_2A, and M₃ receptors, while the mHypoE-46 neurons expressed the 5 H T_2A, D₂, and M₃ receptors. Neither cell line expressed the 5 H T_2C receptor.

CONCLUSION

Similar to observed effects of these agents in rat neurons, induction of AMPK by aripiprazole and olanzapine suggests impaired energy sensing, while suppression of insulin-induced pAKT by clozapine and aripiprazole suggests impaired insulin signalling, seen across both rodent derived hypothalamic cell lines. Conversely, olanzapine-induced suppression of pro-inflammatory IL-6, alongside olanzapine and clozapine-induced IL-10, demonstrate anti-inflammatory effects, which do not corroborate with our prior observations in the rat neuronal line. The different findings between cell lines could be explained by differential expression of neurotransmitters receptors and/or reflect genetic heterogeneity across the rat and mouse lines. However, overall, our findings support direct effects of antipsychotics to impact insulin, energy sensing, and inflammatory pathways in hypothalamic rodent neurons.

Second-Generation Antipsychotics and Dysregulation of Glucose Metabolism: Beyond Weight Gain

Second-generation antipsychotics (SGAs) are the cornerstone of treatment for schizophrenia because of their high clinical efficacy. However, SGA treatment is associated with severe metabolic alterations and body weight gain, which can increase the risk of type 2 diabetes and cardiovascular disease, and greatly accelerate mortality. Several underlying mechanisms have been proposed for antipsychotic-induced weight gain (AIWG), but some studies suggest that metabolic changes in insulin-sensitive tissues can be triggered before the onset of AIWG. In this review, we give an outlook on current research about the metabolic disturbances provoked by SGAs, with a particular focus on whole-body glucose homeostasis disturbances induced independently of AIWG, lipid dysregulation or adipose tissue disturbances. Specifically, we discuss the mechanistic insights gleamed from cellular and preclinical animal studies that have reported on the impact of SGAs on insulin signaling, endogenous glucose production, glucose uptake and insulin secretion in the liver, skeletal muscle and the endocrine pancreas. Finally, we discuss some of the genetic and epigenetic changes that might explain the different susceptibilities of SGA-treated patients to the metabolic side-effects of antipsychotics.

Olanzapine exposure diminishes perfusion and decreases volume of sensorimotor cortex in rats

BACKGROUND

Olanzapine is a frequently used atypical antipsychotic drug known to exert structural brain alterations in animals. This study investigated whether chronic olanzapine exposure alters regional blood brain perfusion assessed by Arterial Spin Labelling (ASL) magnetic resonance imaging (MRI) in a validated model of olanzapine-induced metabolic disturbances. An effect of acute olanzapine exposure on brain perfusion was also assessed for comparison.

METHODS

Adult Sprague-Dawley female rats were treated by intramuscular depot olanzapine injections (100 mg/kg every 14 days) or vehicle for 8 weeks. ASL scanning was performed on a 9.4 T Bruker BioSpec 94/30USR scanner under isoflurane anesthesia. Serum samples were used to assay leptin and TNF-α level while brains were sliced for histology. Another group received only one non-depot intraperitoneal dose of olanzapine (7 mg/kg) during MRI scanning, thus exposing its acute effect on brain perfusion.

RESULTS

Both acute and chronic dosing of olanzapine resulted in decreased perfusion in the sensorimotor cortex, while no effect was observed in the piriform cortex or hippocampus. Furthermore, in the chronically treated group decreased cortex volume was observed. Chronic olanzapine dosing led to increased body weight, adipose tissue mass and leptin level, confirming its expected metabolic effects.

CONCLUSION

This study demonstrates region-specific decreases in blood perfusion associated with olanzapine exposure present already after the first dose. These findings extend our understanding of olanzapine-induced functional and structural brain changes.

Supratherapeutic Psychotropic Drug Levels in the Emergency Department and Their Association with Delirium Duration: A Preliminary Study

OBJECTIVES

Polypharmacy is associated with delirium, but the mechanisms for this connection are unclear. Our goal was to determine the frequency of supratherapeutic psychotropic drug levels (SPDLs) in older hospitalized patients and if it is associated with the duration of emergency department (ED) delirium.

DESIGN

Secondary analysis of a prospective cohort study.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

ED patients 65 years or older who were admitted to the hospital.

MEASUREMENTS

Delirium was assessed in the ED and during the first 7 days of hospitalization using the modified Brief Confusion Assessment Method. Drug concentrations were determined in serum samples collected at enrollment via a novel platform based on liquid chromatography-tandem mass spectrometry capable of identifying and quantitating 78 clinically approved medications including opioids, benzodiazepines, antidepressants, antipsychotics, and amphetamines. Patients with serum psychotropic drug concentrations above established reference ranges were considered supratherapeutic and have a SPDL. We performed proportional odds logistic regression to determine if SPDLs were associated with ED delirium duration adjusted for confounders. Medical record review was performed to determine if the doses of medications associated with SPDLs were adjusted at hospital discharge.

RESULTS

A total of 158 patients were enrolled; of these, 66 were delirious in the ED. SPDLs were present in 11 (17%) of the delirious and 4 (4%) of the non-delirious ED patients. SPDLs were significantly associated with longer ED delirium duration (adjusted proportional odds ratio = 6.0; 95% confidence interval = 2.1-17.3) after adjusting for confounders. Of the 15 medications associated with SPDLs, 9 (60%) were prescribed at the same or higher doses at the time of hospital discharge.

CONCLUSION

SPDLs significantly increased the odds of prolonged ED delirium episodes. Approximately half of the medications associated with SPDLs were continued after hospital discharge at the same or higher doses. J Am Geriatr Soc 67:2387-2392, 2019.

Olanzapine-induced endoplasmic reticulum stress and inflammation in the hypothalamus were inhibited by an ER stress inhibitor 4-phenylbutyrate

Antipsychotics are the most important treatment for schizophrenia. However, antipsychotics, particularly olanzapine and clozapine, are associated with severe weight gain/obesity side-effects. Although numerous studies have been carried out to identify the exact mechanisms of antipsychotic-induced weight gain, it is still important to consider other pathways. Endoplasmic reticulum (ER) stress signaling and its associated inflammation pathway is one of the most important pathways involved in regulation of energy balance. In the present study, we examined the role of hypothalamic protein kinase R like endoplasmic reticulum kinase- eukaryotic initiation factor 2α (PERK-eIF2α) signaling and the inflammatory IkappaB kinase β- nuclear factor kappa B (IKKβ-NFκB) signaling pathway in olanzapine-induced weight gain in female rats. In this study, we found that olanzapine significantly activated PERK-eIF2α and IKKβ-NFκB signaling in SH-SY5Y cells in a dose-dependent manner. Olanzapine treatment for 8 days in rats was associated with activated PERK-eIF2α signaling and IKKβ-NFκB signaling in the hypothalamus, accompanied by increased food intake and weight gain. Co-treatment with an ER stress inhibitor, 4-phenylbutyrate (4-PBA), decreased olanzapine-induced food intake and weight gain in a dose- and time-dependent manner. Moreover, 4-PBA dose-dependently inhibited olanzapine-induced activated PERK-eIF2α and IKKβ-NFκB signaling in the hypothalamus. These results suggested that hypothalamic ER stress may play an important role in antipsychotic-induced weight gain.

Antipsychotics differentially regulate insulin, energy sensing, and inflammation pathways in hypothalamic rat neurons

INTRODUCTION

Second generation antipsychotic (AP)s remain the gold-standard treatment for schizophrenia and are widely used on- and off-label for other psychiatric illnesses. However, these agents cause serious metabolic side-effects. The hypothalamus is the primary brain region responsible for whole body energy regulation, and disruptions in energy sensing (e.g. insulin signaling) and inflammation in this brain region have been implicated in the development of insulin resistance and obesity. To elucidate mechanisms by which APs may be causing metabolic dysregulation, we explored whether these agents can directly impact energy sensing and inflammation in hypothalamic neurons.

METHODS

The rat hypothalamic neuronal cell line, rHypoE-19, was treated with olanzapine (0.25-100 uM), clozapine (2.5-100 uM) or aripiprazole (5-20 uM). Western blots measured the energy sensing protein AMPK, components of the insulin signaling pathway (AKT, GSK3β), and components of the MAPK pathway (ERK1/2, JNK, p38). Quantitative real-time PCR was performed to determine changes in the mRNA expression of interleukin (IL)-6, IL-10 and brain derived neurotrophic factor (BDNF).

RESULTS

Olanzapine (100 uM) and clozapine (100, 20 uM) significantly increased pERK1/2 and pJNK protein expression, while aripiprazole (20 uM) only increased pJNK. Clozapine (100 uM) and aripiprazole (5 and 20 uM) significantly increased AMPK phosphorylation (an orexigenic energy sensor), and inhibited insulin-induced phosphorylation of AKT. Olanzapine (100 uM) treatment caused a significant increase in IL-6 while aripiprazole (20 uM) significantly decreased IL-10. Olanzapine (100 uM) and aripiprazole (20 uM) increased BDNF expression.

CONCLUSIONS

We demonstrate that antipsychotics can directly regulate insulin, energy sensing, and inflammatory pathways in hypothalamic neurons. Increased MAPK activation by all antipsychotics, alongside olanzapine-associated increases in IL-6, and aripiprazole-associated decreases in IL-10, suggests induction of pro-inflammatory pathways. Clozapine and aripiprazole inhibition of insulin-stimulated pAKT and increases in AMPK phosphorylation (an orexigenic energy sensor) suggests impaired insulin action and energy sensing. Conversely, olanzapine and aripiprazole increased BDNF, which would be expected to be metabolically beneficial. Overall, our findings suggest differential effects of antipsychotics on hypothalamic neuroinflammation and energy sensing.

Chronic Antipsychotic Treatment Modulates Aromatase (CYP19A1) Expression in the Male Rat Brain

Antipsychotic drugs, known as the antagonists of dopaminergic receptors, may also affect a large spectrum of other molecular signaling pathways in the brain. Despite the numerous ongoing studies on neurosteroid action and regulation, there are no reports regarding the influence of extended treatment with typical and atypical neuroleptics on brain aromatase (CYP19A1) expression. In the present study, we assessed for the first time aromatase mRNA and protein levels in the brain of rats chronically (28 days) treated with olanzapine, clozapine, and haloperidol using quantitative real-time PCR, end-point RT-PCR, and Western blotting. Both clozapine and haloperidol, but not olanzapine treatment, led to an increase of aromatase mRNA expression in the rat brain. On the other hand, aromatase protein level remained unchanged after drug administration. These results cast a new light on the pharmacology of examined antipsychotics and contribute to a better understanding of the mechanisms responsible for their action. The present report also underlines the complex nature of potential interactions between neuroleptic pharmacological effects and physiology of brain neurosteroid pathways.

One-Year Treatment with Olanzapine Depot in Female Rats: Metabolic Effects

BACKGROUND

Antipsychotic drugs can negatively affect the metabolic status of patients, with olanzapine as one of the most potent drugs. While patients are often medicated for long time periods, experiments in rats typically run for 1 to 12 weeks, showing olanzapine-related weight gain and increased plasma lipid levels, with transcriptional upregulation of lipogenic genes in liver and adipose tissue. It remains unknown whether metabolic status will deteriorate with time.

METHODS

To examine long-term metabolic effects, we administered intramuscular long-acting injections of olanzapine (100 mg/kg BW) or control substance to female rats for up to 13 months.

RESULTS

Exposure to olanzapine long-acting injections led to rapid weight gain, which was sustained throughout the experiment. At 1, 6, and 13 months, plasma lipid levels were measured in separate cohorts of rats, displaying no increase. Hepatic transcription of lipid-related genes was transiently upregulated at 1 month. Glucose and insulin tolerance tests indicated insulin resistance in olanzapine-treated rats after 12 months.

CONCLUSION

Our data show that the continuous increase in body weight in response to long-term olanzapine exposure was accompanied by surprisingly few concomitant changes in plasma lipids and lipogenic gene expression, suggesting that adaptive mechanisms are involved to reduce long-term metabolic adverse effects of this antipsychotic agent in rats.

High-Frequency Neuronal Oscillatory Abnormalities in the Phospholipase C-β1 Knockout Mouse Model of Schizophrenia

BACKGROUND

Schizophrenia is a complex neuropsychiatric disorder characterized by psychoses, socioaffective disturbances, and cognitive deficits. The phosphodiesterase enzyme phospholipase C-β1 has been reported to be reduced in postmortem tissue of schizophrenia patients. Dysregulation of neuronal oscillations, particularly those in the higher frequency range such as beta (12-30 Hz) and gamma (30-80 Hz), are also associated with this disorder. We investigated the influence of phospholipase C-β1 gene deletion on cortical oscillatory activity and sensorimotor gating behavior.

METHODS

Adult phospholipase C-β1 knockout and wild-type C57Bl/6J control mice (total n = 26) underwent surgical implantation of extradural electrodes to allow electrocorticography recordings. Electrocorticography was recorded during prepulse inhibition behavior sessions to measure ongoing and auditory-evoked electrophysiological responses. Mice were also pretreated with antipsychotic drugs haloperidol (0.25 mg/kg), clozapine (2.5 mg/kg), and olanzapine (5 mg/kg).

RESULTS

Phospholipase C-β1 knockout mice exhibited reduced prepulse inhibition and diminished power and phase synchrony of beta and gamma oscillatory responses to auditory stimuli as well as elevated ongoing beta oscillations. Reductions in prepulse inhibition were highly correlated with the power and phase synchrony of evoked oscillations. Clozapine and olanzapine ameliorated the prepulse inhibition deficit in phospholipase C-β1 knockout mice, but not the electrophysiology abnormalities.

CONCLUSIONS

Phospholipase C-β1 reduction leads to disturbances to beta and gamma oscillatory dynamics and prepulse inhibition behavior. The strong relationships between these measures demonstrate the importance of event-related oscillatory activity to sensorimotor gating behavior. However, dissociation of these measures observed in the drug studies suggests that abnormalities in neuronal networks may not necessarily need to be corrected for behavioral improvement.

The effects of antipsychotics on the density of cannabinoid receptors in selected brain regions of male and female adolescent juvenile rats

Antipsychotic drugs have been increasingly prescribed to children and adolescents for treating various mental disorders, such as childhood-onset schizophrenia. The abnormality of endocannabinoid system is involved in the pathophysiology of these disorders in juveniles. This study investigated the effect of antipsychotics on the cannabinoid (CB) receptors in the brain of both male and female juvenile rats. The postnatal rats (PD23±1) were administered aripiprazole (1 mg/kg), olanzapine (1 mg/kg), risperidone (0.3 mg/kg) or vehicle (control) for 3 weeks. Quantitative autoradiography was used to investigate the binding densities of [³H]CP-55940 (an agonist for CB1R and CB2R) and [³H]SR141716A (a selective CB1R antagonist) in the rat brains. Risperidone significantly upregulated the [³H]CP55940 and [³H]SR141716A bindings in the prefrontal cortex (PFC), nucleus accumbens core (NAcC), nucleus accumbens shell (NAcS), cingulate cortex (Cg), and the caudate putamen (CPu) in male rats. Moreover, aripiprazole significantly elevated the [³H]SR141716A binding in the Cg and NAcS of female rats. Furthermore, there is an overall higher [³H]SR141716A binding level in the brain of female rats than male rats. Therefore, treatment with aripiprazole, olanzapine and risperidone could induce differential and gender specific effects on the binding density of cannabinoid receptors in the selected brain regions of childhood/adolescent rats.

Liraglutide prevents metabolic side-effects and improves recognition and working memory during antipsychotic treatment in rats

BACKGROUND

Antipsychotic drugs (APDs), olanzapine and clozapine, do not effectively address the cognitive symptoms of schizophrenia and can cause serious metabolic side-effects. Liraglutide is a synthetic glucagon-like peptide-1 (GLP-1) receptor agonist with anti-obesity and neuroprotective properties. The aim of this study was to examine whether liraglutide prevents weight gain/hyperglycaemia side-effects and cognitive deficits when co-administered from the commencement of olanzapine and clozapine treatment.

METHODS

Rats were administered olanzapine (2 mg/kg, three times daily (t.i.d.)), clozapine (12 mg/kg, t.i.d.), liraglutide (0.2 mg/kg, twice daily (b.i.d.)), olanzapine + liraglutide co-treatment, clozapine + liraglutide co-treatment or vehicle (Control) ( n = 12/group, 6 weeks). Recognition and working memory were examined using Novel Object Recognition (NOR) and T-Maze tests. Body weight, food intake, adiposity, locomotor activity and glucose tolerance were examined.

RESULTS

Liraglutide co-treatment prevented olanzapine- and clozapine-induced reductions in the NOR test discrimination ratio ( p < 0.001). Olanzapine, but not clozapine, reduced correct entries in the T-Maze test ( p < 0.05 versus Control) while liraglutide prevented this deficit. Liraglutide reduced olanzapine-induced weight gain and adiposity. Olanzapine significantly decreased voluntary locomotor activity and liraglutide co-treatment partially reversed this effect. Liraglutide improved clozapine-induced glucose intolerance.

CONCLUSION

Liraglutide co-treatment improved aspects of cognition, prevented obesity side-effects of olanzapine, and the hyperglycaemia caused by clozapine, when administered from the start of APD treatment. The results demonstrate a potential treatment for individuals at a high risk of experiencing adverse effects of APDs.

Subchronic olanzapine exposure leads to increased expression of myelination-related genes in rat fronto-medial cortex

Schizophrenia is a psychotic disorder with severe and disabling symptoms, such as hallucinations, delusions, blunted affect and social withdrawal. The neuropathology remains elusive, but disturbances in immunity-related processes, neuronal connectivity and myelination have consistently been linked to schizophrenia. Antipsychotic drugs can be efficient in reducing symptoms, acting primarily on the dopamine system, but additional biological targets are likely to exist. Here we have screened for novel mechanisms of action in an animal model, using adult rats exposed to long-acting olanzapine, achieving stable and clinically relevant antipsychotic drug concentrations. By microarray-based examination of global gene expression in the fronto-medial cortex, at the single gene- and gene-set level, we observed downregulation of two neuropeptide-encoding genes, Vgf and Cort (fold change -1,25 and -1,48, respectively) in response to olanzapine exposure. Furthermore, we demonstrated significant upregulation of five out of ~2000 GO predefined gene sets after olanzapine exposure. Strikingly, all were linked to myelination and oligodendrocyte development; "Ensheathment of neurons", "Axon ensheathment", "Myelination", "Myelin sheath" and "Oligodendrocyte development" (FDR-values < 25). Sixteen of the leading edge genes in these gene sets were analysed independently by qPCR, of which 11 genes displayed significant upregulation, including Plp1, Mal, Mag and Cnp (fold change: 1,30, 1,50, 1,30 and 1,15, respectively). Several of the upregulated genes (e.g. MAG, MAL and CNP) have previously been reported as downregulated in post-mortem brain samples from schizophrenia patients. Although caution needs to be taken when extrapolating results from animal studies to humans, the data suggest a role for olanzapine in alleviating myelination-related dysfunction in schizophrenia.

Time-dependent effects of olanzapine treatment on the expression of histidine decarboxylase, H1 and H3 receptor in the rat brain: The roles in olanzapine-induced obesity

Antipsychotic treatment, particularly olanzapine and clozapine, induces severe obesity. The Histamine H1 receptor is considered to be an important contributor to olanzapine-induced obesity, however how olanzapine modulates the histaminergic system is not sufficiently understood. This study examined the effect of olanzapine on key molecules of the histaminergic system, including histidine decarboxylase (HDC), H1 receptor (H1R) and H3 receptor (H3R), in the brain at different stages of olanzapine-induced obesity. During short-term treatment (8-day), olanzapine increased hypothalamic HDC mRNA expression and H1R binding in the arcuate nucleus (Arc) and ventromedial hypothalamus (VMH), without changing H3R binding density. HDC mRNA and Arc H1R binding were positively correlated with increased food intake, feeding efficiency and weight gain. When the treatment was extended to 16 and 36 days, H1R binding was increased not only in the hypothalamic Arc and VMH but also in the brainstem dorsal vagal complex (DVC). The H1R bindings in the Arc, VMH and DVC were positively correlated with weight gain induced by olanzapine treatment. However, the expression of HDC and H3R mRNA was not increased. These results suggest that olanzapine time-dependently modulates histamine neurotransmission, which suggested the different neuronal mechanisms underlying different stages of weight gain development. Treatment targeting the H1R may be effective for both short- and long-term olanzapine-induced weight gain.

Intranasal delivery of antipsychotic drugs

Antipsychotic drugs are used to treat psychotic disorders that afflict millions globally and cause tremendous emotional, economic and healthcare burdens. However, the potential of intranasal delivery to improve brain-specific targeting remains unrealized. In this article, we review the mechanisms and methods used for brain targeting via the intranasal (IN) route as well as the potential advantages of improving this type of delivery. We extensively review experimental studies relevant to intranasal delivery of therapeutic agents for the treatment of psychosis and mental illnesses. We also review clinical studies in which intranasal delivery of peptides, like oxytocin (7 studies) and desmopressin (1), were used as an adjuvant to antipsychotic treatment with promising results. Experimental animal studies (17) investigating intranasal delivery of mainstream antipsychotic drugs have revealed successful targeting to the brain as suggested by pharmacokinetic parameters and behavioral effects. To improve delivery to the brain, nanotechnology-based carriers like nanoparticles and nanoemulsions have been used in several studies. However, human studies assessing intranasal delivery of mainstream antipsychotic drugs are lacking, and the potential toxicity of nanoformulations used in animal studies has not been explored. A brief discussion of future directions anticipates that if limitations of low aqueous solubility of antipsychotic drugs can be overcome and non-toxic formulations used, IN delivery (particularly targeting specific tissues within the brain) will gain more importance moving forward given the inherent benefits of IN delivery in comparison to other methods.

Prevention of the adverse effects of olanzapine on lipid metabolism with the antiepileptic zonisamide

BACKGROUND

Atypical antipsychotic drugs, particularly olanzapine, represent a mainstay in the treatment of psychoses; however, their use is commonly associated with weight gain and diabetes. The aim of this study was to determine whether combined administration of olanzapine and zonisamide can be used to prevent olanzapine-induced metabolic disturbances.

METHODS AND RESULTS

These experiments involved female Sprague Dawley rats (n = 6-8/group) that were administered olanzapine, either acutely (6 mg/kg, s. c) or via continuous osmotic minipump infusion (6 mg/kg/day for 6 or 14 days), in combination with zonisamide (26 mg/kg/day,i.p.). Continuous infusion of olanzapine induced accumulation of adipose tissue and an associated reduction in stimulated lipolysis and reduced protein expression of CGI-58, a critical co-activator of ATGL. Olanzapine treatment caused a preferential shift toward carbohydrate oxidation (or reduced fat oxidation), elevated blood triglycerides and a reduction in locomotor activity. Olanzapine had a direct effect on glucose regulation, causing rapid hyperglycemia, and a reduction in glucose tolerance and insulin sensitivity. Continuous administration of olanzapine caused significant hyperinsulinemia and a significant reduction in insulin sensitivity. Zonisamide did not affect the impact of olanzapine on glucose homeostasis. On the other hand, co-administration of olanzapine with zonisamide completely ameliorated olanzapine-mediated shifts in lipid metabolism resulting in a normalization of olanzapine-induced weight gain.

CONCLUSION

These data collectively show an impact of olanzapine on body weight and lipid metabolism, which is ameliorated by co-administration with zonisamide. These findings suggest that a combined olanzapine and zonisamide approach might reduce weight gain, but will not provide protection against olanzapine-induced glucose intolerance.

Chronic Olanzapine Treatment Induces Disorders of Plasma Fatty Acid Profile in Balb/c Mice: A Potential Mechanism for Olanzapine-Induced Insulin Resistance

Background

Atypical antipsychotics such as olanzapine cause metabolic side effects leading to obesity and insulin resistance. The underlying mechanisms remain elusive. In this study we investigated the effects of chronic treatment of olanzapine on the fatty acid composition of plasma in mice.

Methods

Twenty 8-week female Balb/c mice were randomly assigned to two groups: the OLA group and the control group. After treatment with olanzapine (10 mg/kg/day) or vehicle intraperitoneally for 8 weeks, fasting glucose, insulin levels and oral glucose tolerance test were determined. Effects on plasma fatty acid profile and plasma indices of D5 desaturase, D6 desaturase and SCD1 activity were also investigated.

Results

Chronic administration of olanzapine significantly elevated fasting glucose and insulin levels, impaired glucose tolerance, but did not increase body weight. Total saturated fatty acids and n-6 polyunsaturated fatty acids were significantly increased and total monounsaturated fatty acids were significantly decreased, while total n-3 polyunsaturated fatty acids showed no prominent changes. Chronic olanzapine treatment significantly up-regulated D6 desaturase activity while down-regulating D5 desaturase activity. Palmitic acid (C16:0), dihomo-γ-linolenic acid (C20:3n-6) and D6 desaturase were associated with an increase probability of insulin resistance, whereas nervonic acid (C24:1) and SCD1 were significantly associated with a lower insulin resistance probability.

Conclusions

All results indicated that such drug-induced effects on fatty acid profile in plasma were relevant for the metabolic adverse effects associated with olanzapine and possibly other antipsychotics. Further studies are needed to investigate geneticand other mechanisms to explain how plasma fatty acids regulate glucose metabolism and affect the risk of insulin resistance.