Long-term outcomes of delayed clozapine initiation in treatment-resistant schizophrenia: a multicenter retrospective cohort study.

BACKGROUND: Clozapine is the only antipsychotic medication with proven efficacy against treatment-resistant schizophrenia. This multicenter retrospective cohort study aimed to evaluate the impact of a delay in clozapine initiation on long-term outcomes. METHODS: Patients who initiated clozapine treatment between July 2009 and December 2018 were included in this study. According to the length of time from the diagnosis of schizophrenia to clozapine initiation, the patients were categorized into one of three groups: early (≤ 9 years), intermediate (10-19 years), and late (≥ 20 years) initiation. The endpoints were psychiatric rehospitalization and all-cause clozapine discontinuation within 3 years. Hazard ratios (HR) and 95% confidence interval (CI) were estimated using the Fine and Gray method or the Cox proportional hazards model. RESULTS: The incidence rates of rehospitalization within three years, according to the cumulative incidence function, were 32.3% for early, 29.7% for intermediate, and 62.2% for late initiation, respectively. Late initiation had a significantly higher risk of psychiatric rehospitalization than early initiation (HR, 2.94; 95% CI, 1.01- 8.55; P = 0.016 by the Gray's test). The risk of psychiatric rehospitalization was not significantly different between the early and intermediate initiation groups. The incidence rate of all-cause clozapine discontinuation within three years using the Kaplan-Meier method was 13.0% for early, 10.6% for intermediate, and 20.1% for late initiation. The risk of all-cause clozapine discontinuation was not significantly among the groups. The late initiation group had more patients discontinuing because of death due to physical diseases than the other groups. CONCLUSIONS: The study suggests that clozapine should be initiated promptly in patients with treatment-resistant schizophrenia to prevent psychiatric rehospitalization during long-term treatment. Further prospective studies with appropriate consideration of confounding factors and large sample sizes are needed to strengthen the evidence.

Low-dose acyclovir for prophylaxis of varicella-zoster virus reactivation after hematopoietic stem cell transplantation in children.

BACKGROUND: Varicella-zoster virus (VZV) reactivation is a serious complication of hematopoietic stem cell transplantation (HSCT). Although low-dose acyclovir can prevent VZV reactivation after HSCT in adults, the efficacy of a dose of acyclovir lower than the recommended dose, such as 60-80 mg/kg/day in children, is unclear. In this study, we aimed to evaluate the incidence of VZV reactivation after HSCT during and after low-dose acyclovir administration for preventing VZV reactivation in children. METHODS: This single-center retrospective study included children aged ≤15 years who received oral acyclovir (at 15 mg/kg/day) to prevent VZV reactivation after HSCT. We examined the cumulative incidence of VZV reactivation after HSCT, during and after prophylactic acyclovir administration. RESULTS: Fifty-three eligible patients were included in this study, of whom 37 underwent allogeneic HSCT. The median duration of prophylactic acyclovir therapy was 264 days (range: 69-1140 days). VZV reactivation occurred in 13 patients (24.5%, 95% confidence interval [CI]: 14.9-37.6). The cumulative incidence of VZV reactivation 1 and 2 years after HSCT was 6.26% (95% CI: 1.60-15.5) and 20.9% (95% CI: 10.3-34.0), respectively. While only one patient developed VZV reactivation during the administration of prophylactic acyclovir, the cumulative incidence of VZV reactivation increased to 24.2% (95% CI: 12.5-38.0) 1 year after the cessation of acyclovir. CONCLUSION: Low-dose acyclovir (15 mg/kg/day) could be effective for preventing VZV reactivation after HSCT in children because VZV reactivation seldom occurs during the administration of 15 mg/kg/day acyclovir.

Retrospective Cohort Study of Clinical Efficacy and Safety of Cefozopran for Treating Febrile Neutropenia during Chemotherapy in Patients with Lung Cancer.

Febrile neutropenia (FN) is a serious side effect in patients undergoing cancer chemotherapy and frequently proves fatal. Since infection control is crucial in the management of FN, the antimicrobial agent cefozopran (CZOP) has been recommended but not approved for routine use in clinical care of FN in Japan. However, few studies of CZOP in the management of FN have used a thrice daily dose schedule. The aim of this study was to retrospectively compare the efficacy and safety of CZOP at a dose of 1 g three times daily to those of cefepime (CFPM) in the treatment of FN in our lung cancer patients. The response rates of the CZOP and CFPM groups were 89.5% (17/19 cases) and 83.0% (39/47 cases), respectively, with no significant difference between the two groups. The median duration of antimicrobial treatment was 6 days (4-10 days) in the CZOP group and 7 days (3-13 days) in the CFPM group, with no significant difference between groups. The incidence rates of adverse events were 21.1% (4/19 cases) in the CZOP group and 19.1% (9/47 cases) in the CFPM group. No adverse events of Grade 3 or higher were observed in either group. The findings of the present study suggest that CZOP administration at a dose of 1 g three times per day as an antimicrobial treatment alternative against FN.

Polypharmacy in Older Adults with Alzheimer's Disease.

The number of patients with Alzheimer's disease is increasing annually. Most of these patients are older adults with comorbid physical illnesses, which means that they are often treated with a combination of medications for the disease they have and those for Alzheimer's disease. Thus, older adults with Alzheimer's disease are potentially at risk for polypharmacy. In addition, the drug interactions between Alzheimer's disease medications and those for the treatment of physical illnesses may reduce their efficacy and increase side effects. This article reviews polypharmacy and drug interactions in elderly patients with Alzheimer's disease, with a focus on psychotropic drugs.

Effects of a conventional mood stabilizer alone or in combination with second-generation antipsychotics on recurrence rate and discontinuation rate in bipolar I disorder in the maintenance phase: A systematic review and meta-analysis of randomized, placebo-controlled trials.

OBJECTIVES: A systematic review and meta-analysis of double-blind, randomized placebo-controlled trials were conducted to examine how soon an increase in recurrence risk could be observed among bipolar I disorder (BDI) patients who were clinically stable with the combination therapy of mood stabilizers with second-generation antipsychotics (SGA+MS) treatment following second-generation antipsychotics discontinuation (i.e., MS alone) compared with SGA+MS maintenance. METHODS: Embase, PubMed, and CENTRAL databases were used for systematic literature searches until May/22/2020. The primary outcome was the recurrence rate of any mood episode at 6 months. The secondary outcomes were the recurrence rates of manic/hypomanic/mixed and depressive episodes and all-cause discontinuation at 6 months. The recurrence rates at 1, 2, 3, 9, and 12 months were also investigated. RESULTS: Eight studies (mean study duration = 58.25 ± 33.63 weeks) were identified (SGA+MS group [n = 1,456: 3 aripiprazole+MS studies, 1 lurasidone+MS study, 1 olanzapine+MS study, 2 quetiapine+MS studies, 1 ziprasidone+MS study] and placebo+MS group [n = 1,476]). Pooled SGA+MS exhibited lower recurrence rates of any mood episode, manic/hypomanic/mixed episodes, and depressive episodes as well as reduced all-cause discontinuation at every observational point. The risk ratios (95% confidence interval) of the recurrence rate at 6 months were 0.51 (0.39-0.86) for any mood episode, 0.42 (0.30-0.59) for manic/hypomanic/mixed episodes, and 0.39 (0.28-0.54) for depressive episodes. The RR for all-cause discontinuation was 0.67 (0.50-0.89). Both aripiprazole+MS and quetiapine+MS outperformed placebo+MS in the recurrence of any mood, manic/hypomanic/mixed, and depressive episodes at 6 months. CONCLUSIONS: SGA+MS prevented recurrence for up to 12 months for BDI compared with placebo+MS.

Recurrence of Mania or Depression Among Adult Bipolar Patients Who Continued Using Lithium: A Single-group Summary Meta-analysis of Randomized Trials.

BACKGROUND: The exact recurrence rate of bipolar disorder in patients receiving lithium maintenance phase treatment and the modifiers associated with recurrence are still unknown. METHODS: We searched Embase, PubMed, and CENTRAL from inception until April 28, 2020. Outcomes included recurrence rate of any mood episode, depressive episodes, and manic/hypomanic/mixed episodes; all-cause discontinuation rate; and discontinuation rate due to adverse events. A random-effects model, single-group summary meta-analysis was conducted. A meta-regression analysis to examine whether the modifiers (total number of patients, %female, mean age, duration of study, duration of preliminary phase, publication year, bipolar disorder type, mood status at recruitment, presence of a placebo arm, sponsorship, enrichment design, number of treatment arms, and risk of bias for blinding or randomization) were associated with the event rate of the outcomes was also performed. RESULTS: We identified 21 randomized trials (n = 1,415; mean study duration, 78.40 ± 32.10 weeks; %female, 54.85%; mean age, 43.47 ± 4.88 years). The event rates (95% confidence interval [CI]) were as follows: recurrence of any mood episode, 39.8% (32.8%, 47.1%); depressive episodes, 25.6% (18.8%, 34.0%); manic/hypomanic/mixed episodes, 18.5% (13.7%, 24.7%); all-cause discontinuation rate, 67.0% (57.2%, 75.5%); and discontinuation rate due to adverse events, 8.7% (5.1%, 14.7%). After adjusting for multiple testing, our meta-regression analysis showed association only between the all-cause discontinuation rate and presence of a placebo arm. CONCLUSIONS: The recurrence rate of depressive episodes seemed to be higher than the recurrence rate of manic/hypomanic/mixed episodes. The all-cause discontinuation rate was high. However, the studies included in our meta-analysis were of short duration.

The Efficacy and Safety of Lubiprostone for Constipation in Cancer Patients Compared with Non-cancer Patients: A Retrospective Cohort Study.

Lubiprostone is an effective drug for various types of constipation in patients without cancer; however, there is no report on its efficacy and safety in patients with cancer. Our purpose was to evaluate the efficacy and safety of lubiprostone for constipation in cancer patients. We retrospectively studied 124 patients (cancer, N = 67) who were treated with lubiprostone for constipation in our hospital between June 2013 and May 2016. The number of bowel movements (BMs) increased in the both the cancer and non-cancer groups. The mean change in BM frequency did not differ between the two groups. Approximately 70% of patients in both groups had an initial BM within 24 h after administration of lubiprostone. The most common lubiprostone-related adverse events in both groups were diarrhea (38.8 vs. 14%), and nausea (22.4 vs. 8.8%). No lubiprostone-related serious adverse events occurred. Discontinuation due to the side effects of lubiprostone was more frequent in cancer patients (p = 0.023). Logistic regression analysis showed that the risk of discontinuation of lubiprostone in cancer patients was high in patients with a body-mass index (BMI) <22, and low in patients using opioids and magnesium oxide dosage ≥1000 mg/d. Our study showed that while lubiprostone was as effective in cancer patients as in non-cancer patients, in cancer patients it was associated with a high incidence of diarrhea and nausea side effects and warranted caution, especially in patients with a low BMI.

Clinical characteristics of elderly depressive patients with low metaiodobenzylguanidine uptake.

BACKGROUND: Recently, depression with Lewy body pathology before the appearance of parkinsonism and cognitive dysfunction has been drawing attention. Low cardiac metaiodobenzylguanidine (MIBG) uptake is helpful for early differentiation of Lewy body disease (LBD) from late-onset psychiatric disorders even before parkinsonism or dementia appears. In this study, we used MIBG uptake as a tool in suspected LBD, and evaluated the relationship of MIBG results to clinical characteristics and depressive symptoms. METHODS: Fifty-two elderly inpatients with depression were included in this study. The Hamilton Depression Rating Scale (HDRS) was administered at admission, and 123 I-MIBG cardiac scintigraphy was performed. Of 52 patients, 38 had normal and 14 had reduced MIBG uptake. RESULTS: Correlation analyses of the late phase heart-to-mediastinum (H/M) ratio on the MIBG test and each item of the HDRS revealed that the H/M ratio was significantly correlated with scores of 'agitation', 'anxiety-somatic', and 'retardation' on the HDRS. Mean HDRS composite scores of 'somatic and psychic anxiety (Marcos)' and 'somatic anxiety/somatization factor (Pancheri)' were higher in the low uptake group than in the normal uptake group. CONCLUSION: Elderly patients with depression who manifested an obvious somatic anxiety tend to show low MIBG uptake, and are more likely to have Lewy body pathology.

Effects of Magnesium Oxide on the Serum Duloxetine Concentration and Antidepressant-Like Effects of Duloxetine in Rats.

Duloxetine is a serotonin/noradrenaline reuptake inhibitor that is used as an antidepressant. However, it is known to cause constipation as a side effect. Magnesium compounds, such as magnesium oxide and magnesium hydroxide aqueous solution, are often combined with duloxetine to ameliorate the constipation caused by duloxetine. However, there is concern that these magnesium compounds might alter the effects of duloxetine via physicochemical interactions. In this study, we attempted to clarify the interactions that take place between duloxetine and magnesium oxide using in vivo and in vitro experiments. We evaluated the influence of magnesium oxide on in vitro duloxetine concentrations using HPLC. In addition, we examined the in vivo antidepressant-like effects and serum concentrations of duloxetine in rats. In the in vitro experiment, the duloxetine concentration was significantly decreased by co-treatment with magnesium oxide. In the in vivo experiment, the antidepressant-like effects of duloxetine were not affected by the combined oral administration of magnesium oxide and a duloxetine formulation although the serum duloxetine level was significantly decreased. However, the antidepressant-like effects of a duloxetine reagent were significantly attenuated by the co-administration of magnesium oxide. These results suggest that duloxetine and magnesium oxide directly interact and that such interactions affect the absorption and antidepressant-like effects of duloxetine.

Photoinitiator-Initiated Estrogenic Activity in Human Breast Cancer Cell Line MCF-7.

A recent in vitro study reported that the photoinitiator 2-isopropylthioxanthone (2-ITX) is an endocrine-disrupting compound (EDC). However, it is not clear whether other photoinitiators such as 1-hydroxycyclohexyl phenyl ketone (1-HCHPK) and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMP) produce endocrine-disrupting effects. The purpose of this study was thus to assess the association between estrogenic activity and exposure to photoinitiators. For estimation of the proliferative effect of the photoinitiators, the E-screen assay was used. Six photoinitiators, 2,2-dimethoxy-2-phenylacetophenone (2,2-DMPAP), 2-ethylhexyl 4-(dimethylamino)benzoate (2-EHDAB), 1-HCHPK, 2-ITX, methyl-2-benzoylbenzoate (MBB), and MTMP, significantly increased number of MCF-7 cells, an estrogen-sensitive human breast cancer cell line. In addition, pretreatment with estrogen receptor (ER) antagonists such as clomiphene, tamoxifen, or fulvestrant, significantly reversed the proliferative effect of each photoinitiator. Data demonstrated that the six photoinitiators produced endocrine-disrupting effects and that these photoinitiators interacted with ER as agonists. Evidence indicates that the six photoinitiators demonstrated estrogenic activity via ER as agonists.

Differential combined effect of COX inhibitors on cell survival suppressed by sorafenib in the HepG2 cell line.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Sorafenib, a molecular-targeted drug, is a multi-target oral anti-neoplastic drug that is used as a first-line treatment for patients with advanced Human HCC. An increase in the expression of the cyclooxygenase-2 (COX-2) protein and sequential production of prostaglandin (PG) E2 were previously shown to significantly enhance carcinogenesis. Although the synergistic and/or additive effects of various COX inhibitors have been demonstrated in HCC, those of a combination of sorafenib and COX inhibitors remain unclear. The aim of the present study was to examine the antitumor effects of a combination of sorafenib and COX inhibitors on HCC HepG2 cells. Various COX inhibitors suppressed HepG2 cell survival, and exhibited a combined effect with sorafenib. However, COX-2 selectivity had little relevance. The co-administration of COX inhibitors and sorafenib increased the frequency of apoptosis. Moreover, the combination of sorafenib and diclofenac significantly increased Bax protein expression levels. The results of the present study indicate that COX inhibitors can be administered in combination with sorafenib for HCC therapy.

Characteristics of the runway model of intracranial self-stimulation behavior and comparison with other motivated behaviors.

Motivation incorporates several psychological aspects that produce reward-related and learning behaviors. Although reward-related behavior is reported to be mediated by the dopaminergic reward pathway, the involvement of dopaminergic systems in motivated behavior has not been fully clarified. Several experimental methodologies for motivational behavior have been reported, but pharmacological characteristics seem to vary among these methodologies. In this review, we attempt to summarize three main concepts:(1) the relationship of dopamine neuron physiology with motivated behavior, (2) the pharmacological characteristics of the runway intracranial self-stimulation model, and (3) the behavioral distinction of disparate motivated behaviors.

Comprehensive signal detection of delirium-associated medication using the Food and Drug Administration Adverse Event Reporting System.

OBJECTIVE: Several medications are associated with delirium; however, studies with adequate statistical power are limited, and it is difficult to determine the effects of the various concomitant medications used in clinical practice. Therefore, in this study, we aimed to comprehensively evaluate the safety signals of delirium-associated drugs using a spontaneous adverse event reporting system. METHOD: The JAPIC AERS (Food and Drug Administration Adverse Event Reporting System pre-processed by the Japan Pharmaceutical Information Center) was used for the analysis in this pharmacovigilance study. The reporting odds ratio (ROR) for delirium was adjusted for using multivariate logistic regression analysis with sex, age, indication, and melatonin receptor agonist use, and 22 drug categories were targeted as covariates. RESULTS: After excluding patients with missing information, 7,527,568 patients were included in the study. Delirium signals were detected even after adjusting for covariates in 17 drug categories, including benzodiazepines (adjusted ROR, 1.76; 95% confidence interval [CI], 1.64-1.89), opioids (adjusted ROR, 4.42; 95% CI, 4.21-4.64), and tricyclic antidepressants (adjusted ROR, 2.44; 95% CI, 2.20-2.71). CONCLUSIONS: These findings suggest that many drug classes, such as benzodiazepines, are independent risk factors for delirium and strengthen the evidence of an association between delirium and medications.

Newer antidepressant for Japanese adults with major depressive disorder: A systematic review and meta-analysis.

INTRODUCTION: The question remains to be elucidated: "Is treatment with antidepressants at doses approved in Japan effective for Japanese patients with MDD?" It is crucial to confirm this in order to provide appropriate treatments for Japanese patients with major depressive disorder (MDD). Therefore, we conducted a systematic review and random-effects pairwise meta-analysis including these nine double-blind, randomized, placebo-controlled trials. METHODS: We calculated the standardized mean difference (SMD) and risk ratio (RR) with a 95% confidence interval (95% CI). RESULTS: Pooled newer antidepressants outperformed placebo regarding improvement of depressive symptom scale scores [SMD (95% CI) = -0.20 (-0.27, -0.12), p < 0.00001], response to treatment [RR (95% CI) = 1.23 (1.13, 1.32), p < 0.00001], and remission rate [RR (95% CI) = 1.30 (1.16, 1.45), p < 0.00001]. Although all-cause discontinuation was not significantly different between the treatment groups, the pooled antidepressant group showed a higher discontinuation rate due to adverse event [RR (95% CI) = 1.60 (1.13, 2.26), p = 0.007] and a higher incidence of at least one adverse event than the placebo group [RR (95% CI) = 1.13 (1.08, 1.18), p < 0.00001]. DISCUSSION: We concluded that newer antidepressants are effective for Japanese adults with MDD although the clinicians must monitor the health conditions of these individuals.

Anxiolytic-like effects of hochuekkito in lipopolysaccharide-treated mice involve interleukin-6 inhibition.

Hochuekkito (HET) is a Kampo medicine used to treat postoperative and post-illness general malaise and decreased motivation. HET is known to regulate immunity and modulate inflammation. However, the precise mechanism and effects of HET on inflammation-induced central nervous system disorders remain unclear. This study aimed to assess the effect of HET on inflammation-induced anxiety-like behavior and the mechanism underlying anxiety-like behavior induced by lipopolysaccharide (LPS). Institute of Cancer Research mice were treated with LPS (300 µg/kg, intraperitoneally), a bacterial endotoxin, to induce systemic inflammation. The mice were administered HET (1.0 g/kg, orally) once a day for 2 weeks before LPS treatment. The light-dark box test and the hole-board test were performed 24 h after the LPS injection to evaluate the effects of HET on anxiety-like behaviors. Serum samples were obtained at 2, 5, and 24 h after LPS injection, and interleukin-6 (IL-6) levels in serum were measured. Human and mouse macrophage cells (THP-1 and RAW264.7 cells, respectively) were used to investigate the effect of HET on LPS-induced IL-6 secretion. The repeated administration of HET prevented anxiety-like behavior and decreased serum IL-6 levels in LPS-treated mice. HET significantly suppressed LPS-induced IL-6 secretion in RAW264.7 and THP-1 cells. Similarly, glycyrrhizin, one of the chemical constituents of HET, suppressed LPS-induced anxiety-like behaviors. Our study revealed that HET ameliorated LPS-induced anxiety-like behavior and inhibited IL-6 release in vivo and in vitro. Therefore, we postulate that HET may be useful against inflammation-induced anxiety-like behavior.

Bumetanide prevents diazepam-modified anxiety-like behavior in lipopolysaccharide-treated mice.

Benzodiazepine receptor agonists are widely prescribed therapeutic agents that alter gamma-aminobutyric acid (GABA)A receptor activity and have anxiolytic effects. Post-operative use of benzodiazepines is a risk factor of delirium. Inflammatory conditions alter the anxiolytic effects of benzodiazepine. We investigated the effect of diazepam, a typical benzodiazepine anxiolytic, on changes in the emotional behavior of mice in a hole-board test after lipopolysaccharide (LPS) treatment. Diazepam dose-dependently increased the number of head-dips at doses that did not alter locomotor activity; however, diazepam dose-dependently significantly decreased the number of head-dips at doses that did not alter locomotor activity in LPS-treated mice. Flumazenil, a benzodiazepine receptor antagonist, normalized the decrease in head-dipping behavior caused by diazepam treatment in normal and LPS-treated mice. The decrease of the head-dipping effect caused by diazepam was attenuated by minocycline in LPS-treated mice. We further found that the decrease in head-dipping behavior caused by diazepam was blocked by bumetanide, a Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) antagonist, in LPS-treated mice. These findings suggest that diazepam induces the anxiety-like behavior under inflammation conditions, and may cause the GABAA receptor dysfunction associated with the chloride plasticity mediated by NKCC1, which contributes to benzodiazepine-induced delirium after surgery.

Intracranial self-stimulation-reward or immobilization-aversion had different effects on neurite extension and the ERK pathway in neurotransmitter-sensitive mutant PC12 cells.

Various actions trigger pleasure (reward) or aversion (punishment) as emotional responses. Emotional factors that negatively affect brain neural control processes for long periods of time might cause various mental diseases by inducing neuronal changes. In the present study, newly developed PC12m12 cells which are　highly sensitivity to neurotransmitters such as acetylcholine (ACh), were used. Exposing the cells to plasma from rats that had been subjected to intracranial self-stimulation (ICSS) markedly upregulated neurite outgrowth. In addition, voluntary running in a wheel or forced on a rotating rod was used to induce behavioral excitation in rats, and examinations of their plasma confirmed that the ICSS-induced neurite outgrowth was not associated with the ICSS behavior itself. Furthermore, immunoblotting and treatment with U0126, an ERK (extracellular signal-regulated kinase) antagonist, showed that the ICSS-induced neurite outgrowth was related to neuronal ERK activity. Exposing the same cells to plasma from rats that had been subjected to immobilization (IMM) also increased neurite outgrowth. Although the degree of enhancement was not as great as that seen after the ICSS rat plasma treatment, it was less than that observed after treatment with ACh as a positive control. These results indicate that ICSS or IMM lead to varying degrees of morphological changes, such as enhanced neurite outgrowth, in PC12m12 cells, but the neuronal signal transduction pathways underlying these effects differ; i.e.,the former morphological change might involve the activation of the ERK pathway, whereas the latter changes might not. Using PC12m12 cells which exhibit sensitivity to neurotransmitters, it might be possible to clarify the pathogeneses of mental diseases at the neuronal level and search for therapeutic drugs.

Development of an appropriate simple suspension method for valganciclovir medication.

BACKGROUND: Valganciclovir (VGC) is essential for preventing cytomegalovirus infections after transplants in adult and pediatric patients. In pediatric patients, VGC tablets have to be pulverized so that they can be delivered via nasogastric tubes. The "simple suspension method" is usually used to suspend tablets in hot water in Japan. However, the optimal suspension conditions and metering methods for preparing VGC suspensions using the simple suspension method are unclear. The purpose of this study was to clarify these issues. METHODS: VGC tablets were suspended in water (initial water temperature: 25 °C or 55 °C) using the simple suspension method. The residual rate of VGC after it had been suspended in hot water was determined using HPLC. In addition, the suspended solution was passed through 6, 8, and 12 Fr. gavage tubes. The VGC concentrations of suspensions produced using different preparation methods were also determined using HPLC. RESULTS: Cracking the surfaces of VGC tablets and suspending them in water at an initial temperature of 55 °C was effective at dissolving the tablets. The VGC concentration of the suspension remained stable for at least 80 min. Furthermore, the VGC concentration remained stable for 48 h during cold dark storage. Cracking the surfaces of VGC tablets could be a more effective metering method than preparing powder from VGC tablets. In addition, little VGC remained in 6, 8, or 12 Fr. gavage tubes after VGC solution was passed through them. CONCLUSION: The amount of VGC should be measured carefully when preparing VGC solutions using the simple suspension method.

Influence of lipopolysaccharide on diazepam-modified loss of righting reflex duration by pentobarbital treatment in mice.

Benzodiazepine receptor agonists are widely prescribed therapeutic agents, alter gamma-aminobutyric acid (GABA)A receptor function, and have hypnotic, anxiolytic, anticonvulsant, and antispastic effects. GABAA receptor activity increases under systemic inflammatory conditions. We investigated the effect of benzodiazepine receptor agonists on pentobarbital-induced loss of righting reflex (LORR) duration using a mouse model of lipopolysaccharide (LPS)-induced inflammation. We assessed pentobarbital-induced LORR duration 24 h after LPS treatment in mice. Additionally, we examined the microglial response by immunohistochemistry and serum IL-6 and TNF-α concentrations in mice. LPS treatment significantly increased the duration of pentobarbital-induced LORR in mice treated with benzodiazepine receptor agonists (diazepam and brotizolam) and a GABAA receptor agonist (muscimol) compared to that of mice treated with vehicle. These effects were blocked by bicuculline, a GABAA receptor antagonist. LPS significantly increased the number of ionized calcium binding adapter molecule-1-positive hippocampal cells 2 and 24 h after treatment. The enhancing effect of diazepam in LPS-treated mice was significantly reduced by minocycline. These findings suggest that LPS enhances pentobarbital-induced LORR duration in mice treated with benzodiazepine via GABAA receptor activity.