The antidepressant effects of risperidone and olanzapine in bipolar disorder.
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OBJECTIVE: To describe the antidepressant effectiveness of olanzapine and risperidone and compare their tolerability when employed adjunctively in bipolar I/II disorder. METHOD: In an observational study, twenty-one ambulatory subjects with DSM-IV defined bipolar I/II disorder, in any phase of the illness, openly received adjunctive risperidone or olanzapine. The primary efficacy parameters were the Hamilton Depression Rating Scale (HDRS-17) and the Maier and Philips Severity Subscale. Secondary efficacy parameters included the Young Mania Rating Scale (YMRS) along with the Clinical Global Impressions Scale (CGI). Response was defined as a significant change from baseline to endpoint in the total mean HDRS-17 score. The primary tolerability parameters were the Abnormal Involuntary Movement Scale (AIMS) along with changes in weight and body mass index (BMI-kg/m2). Patients were evaluated prospectively with repeated monthly assessments for up to 6 months. RESULTS: Eleven patients openly received risperidone; 10 received olanzapine adjunctive to either lithium or divalproex. Total mean HDRS-17 scores significantly decreased from baseline to endpoint in both groups (p=0.001), with the mean HDRS-17 total scores falling from 17(SD=3.2) to 5(SD=1.5) by 6 months in the risperidone-treated group and from 18 (SD=1.9) to 7 (SD=2.0) in the olanzapine-treated group. Differences between the risperidone-treated group and the olanzapine-treated group were not significant at 6 months (p=0.754). The mean doses of study medication were 2.88 (SD=1.6) mg/day for the risperidone-treated group and 12.69 (SD=2.3) mg/day for the olanzapine-treated group. Both risperidone and olanzapine were generally well tolerated. No patients developed tardive dyskinesia. Significant weight gain was experienced by patients in both groups [mean weight gain at endpoint was 5.9 kg in risperidone (p=0.023) and 11.3 kg in olanzapine (p=0.001)]. There was a significant difference in weight gain between the risperidone-treated group and the olanzapine-treated group (p=0.001). CONCLUSIONS: These pilot data, from the first prospective comparison study of risperidone and olanzapine in bipolar disorder, suggest that adjunctive administration of either agent may reduce depressive symptom severity. No subjects receiving risperidone or olanzapine developed tardive dyskinesia. Both compounds imparted substantial weight gain with significantly more weight gain accrual with olanzapine. As this was an observational study, the antidepressant effect and tolerability profile of these compounds requires validation via double-blind placebo controlled investigations. (+info)
Efficacy of olanzapine combined with valproate or lithium in the treatment of dysphoric mania.
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BACKGROUND: Few controlled studies examine the treatment of depressive features in mania. AIMS: To evaluate the efficacy of olanzapine, in combination with lithium or valproate, for treating depressive symptoms associated with mania. METHOD: Secondary analysis of a 6-week, double-blind, randomised study of olanzapine (5-20 mg/day) or placebo combined with ongoing valproate or lithium open treatment for 344 patients in mixed or manic episodes. This analysis focused on a dysphoric subgroup with baseline Hamilton Rating Scale for Depression (HRSD) total scores of 20 or over contrasted with non-dysphoric patients. RESULTS: In the dysphoric subgroup (n=85) mean HRSD total score improvement was significantly greater in olanzapine co-therapy patients than in those receiving placebo plus lithium or valproate (P<0.001). Substantial contributors to this superiority included the HRSD Maier sub-scale (P=0.013) and the suicide item (P=0.001). Total Young Mania Rating Scale improvement was also superior with olanzapine co-therapy. CONCLUSIONS: In patients with acute dysphoric mania, addition of olanzapine to ongoing lithium or valproate monotherapy significantly improved depressive symptom, mania and suicidality ratings. (+info)
Best evidence topic report: no clinical evidence for gastric lavage in lithium overdose.
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A short cut review was carried out to establish the published evidence for gastric lavage in lithium overdose. Altogether 20 papers were found using the reported search, of which none presented the best evidence to answer the clinical question. A clinical bottom line is stated. (+info)
Gabapentin for overactive bladder and nocturia after anticholinergic failure.
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INTRODUCTION: We reviewed our experience with the use of gabapentin to treat symptoms of overactive bladder (OAB) and nocturia in patients who have failed conventional anticholinergic therapy. METHODS: Thirty-one patients referred to us with refractory (OAB) and/or nocturia were treated with oral gabapentin. All the patients had tried or remained on antimuscarinic drugs during treatment. Twenty-four of 31 complained of bothersome symptoms during day and night and the other seven had primary complaints of nocturia. Initial gabapentin doses ranged from 100-300 mg at bedtime. Dose was slowly titrated up to 3,000 mg based on patients' symptomatology and tolerability. RESULTS: The mean age was 51 years old (range 27-78). There were 13 men and 18 women. The median steady state dose chosen by the patient after initial titration was 600 mg/day. Fourteen of 31 patients reported subjective improvement of their frequency and 8 have been on the medication for over 12 months with persistent efficacy. For the 14 improved patients, mean frequency/24 hours decreased from 14.1 +/- 2.2 to 10.0 +/- 2.1. Three patients with primary nocturia reported improvement from a mean of 4.0 +/- 1.3 to 1.0 +/- 0.3 episodes/night. Six patients stopped taking the drug within one month due to side effects mostly described as drowsiness or lethargy. CONCLUSIONS: Fourteen of 31 patients with refractory (OAB) and nocturia improved with oral gabapentin. Gabapentin was generally well tolerated and can be considered in selective patients when conventional modalities have failed. (+info)
Differential effects of amphetamines-induced neurotoxicity on appetitive and aversive Pavlovian conditioning in mice.
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The abuse of substituted amphetamines such as methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA/Ecstasy) can result in neurotoxicity, manifested as the depletion of dopamine (DA) and 5-hydroxytriptamine (5-HT; serotonin) axon terminal markers in humans and animal models. Human METH and MDMA users exhibit impairments in memory and executive functions, which may be a direct consequence of the neurotoxic potential of amphetamines. The objective of this study was to investigate the influence of amphetamines-induced neurotoxicity on Pavlovian learning. Using mouse models of selective DA neurotoxicity (METH; 5 mg/kg x 3), selective 5-HT neurotoxicity (fenfluramine /FEN; 25 mg/kg x 4) and dual DA and 5-HT neurotoxicity (MDMA; 15 mg/kg x 4), appetitive and aversive conditioning were investigated. Dopaminergic neurotoxicity significantly impaired METH and cocaine conditioned place preference (CPP), but had no effect on LiCl-induced conditioned place aversion (CPA). In contrast, serotonergic neurotoxicity significantly enhanced CPP, and had no effect on CPA. Dual dopaminergic/serotonergic neurotoxicity had no apparent effect on CPP; however, CPA was significantly attenuated. Postmortem analysis revealed that significantly diminished levels of DA and 5-HT markers persisted in the striatum, frontal cortex, hippocampus, and amygdala. These findings suggest that amphetamines-induced dopaminergic and serotonergic neurotoxicity exert opposing influences on the affective state produced by subsequent drug reward, while dual dopaminergic/serotonergic neurotoxicity impairs associative learning of aversive conditioning. Furthermore, results revealed that amphetamines-induced DA and 5-HT neurotoxicity modulates appetitive Pavlovian conditioning similar to other DA and 5-HT neurotoxins. Modulation of Pavlovian conditioning by amphetamines-induced neurotoxicity may be relevant to compulsive drug-seeking behavior in METH and MDMA abusers. (+info)
Role of glycogen synthase kinase 3beta in rapamycin-mediated cell cycle regulation and chemosensitivity.
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The mammalian target of rapamycin is a serine-threonine kinase that regulates cell cycle progression. Rapamycin and its analogues inhibit the mammalian target of rapamycin and are being actively investigated in clinical trials as novel targeted anticancer agents. Although cyclin D1 is down-regulated by rapamycin, the role of this down-regulation in rapamycin-mediated growth inhibition and the mechanism of cyclin D1 down-regulation are not well understood. Here, we show that overexpression of cyclin D1 partially overcomes rapamycin-induced cell cycle arrest and inhibition of anchorage-dependent growth in breast cancer cells. Rapamycin not only decreases endogenous cyclin D1 levels but also decreases the expression of transfected cyclin D1, suggesting that this is at least in part caused by accelerated proteolysis. Indeed, rapamycin decreases the half-life of cyclin D1 protein, and the rapamycin-induced decrease in cyclin D1 levels is partially abrogated by proteasome inhibitor N-acetyl-leucyl-leucyl-norleucinal. Rapamycin treatment leads to an increase in the kinase activity of glycogen synthase kinase 3beta (GSK3beta), a known regulator of cyclin D1 proteolysis. Rapamycin-induced down-regulation of cyclin D1 is inhibited by the GSK3beta inhibitors lithium chloride, SB216763, and SB415286. Rapamycin-induced G1 arrest is abrogated by nonspecific GSK3beta inhibitor lithium chloride but not by selective inhibitor SB216763, suggesting that GSK3beta is not essential for rapamycin-mediated G1 arrest. However, rapamycin inhibits cell growth significantly more in GSK3beta wild-type cells than in GSK3beta-null cells, suggesting that GSK3beta enhances rapamycin-mediated growth inhibition. In addition, rapamycin enhances paclitaxel-induced apoptosis through the mitochondrial death pathway; this is inhibited by selective GSK3beta inhibitors SB216763 and SB415286. Furthermore, rapamycin significantly enhances paclitaxel-induced cytotoxicity in GSK3beta wild-type but not in GSK3beta-null cells, suggesting a critical role for GSK3beta in rapamycin-mediated paclitaxel-sensitization. Taken together, these results show that GSK3beta plays an important role in rapamycin-mediated cell cycle regulation and chemosensitivity and thus significantly potentiates the antitumor effects of rapamycin. (+info)
Regulation of gene expression by lithium and depletion of inositol in slices of adult rat cortex.
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Lithium inhibits inositol monophosphatase at therapeutically effective concentrations, and it has been hypothesized that depletion of brain inositol levels is an important chemical alteration for lithium's therapeutic efficacy in bipolar disorder. We have employed adult rat cortical slices as a model to investigate the gene regulatory consequences of inositol depletion effected by lithium using cytidine diphosphoryl-diacylglycerol as a functionally relevant biochemical marker to define treatment conditions. Genes coding for the neuropeptide hormone pituitary adenylate cyclase activating polypeptide (PACAP) and the enzyme that processes PACAP's precursor to the mature form, peptidylglycine alpha-amidating monooxygenase, were upregulated by inositol depletion. Previous work has shown that PACAP can increase tyrosine hydroxylase (TH) activity and dopamine release, and we found that the gene for GTP cyclohydrolase, which effectively regulates TH through synthesis of tetrahydrobiopterin, was also upregulated by inositol depletion. We propose that modulation of brain PACAP signaling might represent a new opportunity in the treatment of bipolar disorder. (+info)
Chronic lithium chloride administration to unanesthetized rats attenuates brain dopamine D2-like receptor-initiated signaling via arachidonic acid.
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We studied the effect of lithium chloride on dopaminergic neurotransmission via D2-like receptors coupled to phospholipase A2 (PLA2). In unanesthetized rats injected i.v. with radiolabeled arachidonic acid (AA, 20:4 n-6), regional PLA2 activation was imaged by measuring regional incorporation coefficients k* of AA (brain radioactivity divided by integrated plasma radioactivity) using quantitative autoradiography, following administration of the D2-like receptor agonist, quinpirole. In rats fed a control diet, quinpirole at 1 mg/kg i.v. increased k* for AA significantly in 17 regions with high densities of D2-like receptors, of 61 regions examined. Increases in k* were found in the prefrontal cortex, frontal cortex, accumbens nucleus, caudate-putamen, substantia nigra, and ventral tegmental area. Quinpirole, 0.25 mg/kg i.v. enhanced k* significantly only in the caudate-putamen. In rats fed LiCl for 6 weeks to produce a therapeutically relevant brain lithium concentration, neither 0.25 mg/kg nor 1 mg/kg quinpirole increased k* significantly in any region. Orofacial movements following quinpirole were modified but not abolished by LiCl feeding. The results suggest that downregulation by lithium of D2-like receptor signaling involving PLA2 and AA may contribute to lithium's therapeutic efficacy in bipolar disorder. (+info)