Background: Viloxazine ER (viloxazine extended-release capsules; Qelbree), a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment, has known activity as a norepinephrine (NE) transporter (NET) inhibitor. In vitro studies have also shown direct pharmacological effects on specific serotonin (5-HT) receptors, but not on the serotonin transporter (SERT). An in vivo microdialysis study in rats showed viloxazine (50 mg/kg i.
View Article and Find Full Text PDFThe observation that cholinergic deafferentation of circuits projecting from forebrain basal nuclei to frontal and hippocampal circuits occurs in Alzheimer's disease has led to drug-targeting of muscarinic M1 receptors to alleviate cognitive symptoms. The high homology within the acetylcholine binding domain of this family however has made receptor-selective ligand development challenging. This work presents the synthesis scheme, pharmacokinetic and structure-activity-relationship study findings for M1-selective ligand, LY593093.
View Article and Find Full Text PDFA wider diversity of drug treatments to aid smoking cessation is needed to help tailor the most efficacious treatment for different types of smokers. This study was conducted to determine whether amitifadine, which inhibits re-uptake of dopamine, norepinephrine and serotonin, would decrease nicotine self-administration at doses that do not cause adverse side effects. Adult female Sprague-Dawley rats were trained to self-administer nicotine intravenous (IV) and were given acute doses of amitifadine in a repeated measures counterbalanced design.
View Article and Find Full Text PDFAmitifadine (EB-1010, formerly DOV 21,947) is a serotonin-preferring triple reuptake inhibitor that is a drug candidate for major depressive disorder. We investigated several relevant biopharmaceutic and drug-like characteristics of amitifadine using in vitro methodology and additionally determined the in vivo brain to plasma ratio of the drug in rats. Amitifadine was highly plasma protein bound with over 99% of drug bound to human plasma proteins.
View Article and Find Full Text PDFRationale: Treatment of attention-deficit/hyperactivity disorder (ADHD) has for many years relied on psychostimulants, particularly various formulations of amphetamines and methylphenidate. These are central nervous system stimulants and are scheduled because of their abuse potential. Atomoxetine (atomoxetine hydrochloride; Strattera®) was approved in 2002 for treatment of ADHD, and was the first nonstimulant medication approved for this disorder.
View Article and Find Full Text PDFWe report on the pharmacological, behavioral, and neurochemical characterization of a novel dual norepinephrine (NE)/dopamine (DA) transporter inhibitor EB-1020 (1R,5S)-1-(naphthalen-2-yl)-3-azabicyclo[3.1.0]hexane HCl).
View Article and Find Full Text PDFMajor depressive disorder is a prevalent disease, and current pharmacotherapy is considered to be inadequate. It has been hypothesized that a triple reuptake inhibitor (TRI) that activates dopamine (DA) neurotransmission in addition to serotonin and norepinephrine (NE) circuitries may result in enhanced antidepressant effects. Here, we investigated the pharmacological effects of a serotonin-preferring TRI-amitifadine (EB-1010, formerly DOV 21947).
View Article and Find Full Text PDFDepression and pain disorders are often diagnosed in the same patients. Here we summarize the shared pathophysiology between both disorders and the importance of addressing all symptoms in patients with comorbid pain and depression. We describe anatomical structures that are activated and/or altered in response to both depression and pain--examples include the insular cortex, the prefrontal cortex, the anterior cingulate cortex, the amygdala, and the hippocampus.
View Article and Find Full Text PDFVarious lines of evidence indicate the presence of progressive pathophysiological processes occurring within the brains of patients with schizophrenia. By modulating chemical neurotransmission, antipsychotic drugs may influence a variety of functions regulating neuronal resilience and viability and have the potential for neuroprotection. This article reviews the current literature describing preclinical and clinical studies that evaluate the efficacy of antipsychotic drugs, their mechanism of action and the potential of first- and second-generation antipsychotic drugs to exert effects on cellular processes that may be neuroprotective in schizophrenia.
View Article and Find Full Text PDFOlanzapine (OLZ), one of the second-generation atypical antipsychotics (SGAs), has shown relative advantages in patient adherence and outcomes. However, OLZ has also been associated with a higher incidence of weight gain than most other SGAs. Excessive weight gain may in turn contribute to long-term health concerns for some individuals.
View Article and Find Full Text PDFDisruption of cholinergic neurotransmission contributes to the memory impairment that characterizes Alzheimer disease (AD). Since the amyloid cascade hypothesis of AD pathogenesis postulates that amyloid beta (A beta) peptide accumulation in critical brain regions also contributes to memory impairment, we assessed cholinergic function in transgenic mice where the human A beta peptide is overexpressed. We first measured hippocampal acetylcholine (ACh) release in young, freely moving PDAPP mice, a well-characterized transgenic mouse model of AD, and found marked A beta-dependent alterations in both basal and evoked ACh release compared with WT controls.
View Article and Find Full Text PDFAtomoxetine is a selective inhibitor of norepinephrine transporters and is currently being used in the pharmacotherapy of attention deficit/hyperactivity disorder (ADHD). We have previously shown that atomoxetine increased extracellular (EX) concentrations of norepinephrine and dopamine in prefrontal cortex, but unlike the psychostimulant methylphenidate, did not alter dopamine(EX) in nucleus accumbens or striatum. Using the in vivo microdialysis technique in rat, we investigated the effects of atomoxetine on norepinephrine(EX) and dopamine(EX) concentrations in several other brain regions and also evaluated the role of inhibitory autoreceptors on atomoxetine-induced increases of norepinephrine(EX) concentrations.
View Article and Find Full Text PDFFMPD [6-fluoro-10-[3-(2-methoxyethyl)-4-methyl-piperazin-1-yl]-2-methyl-4H-3-thia-4,9-diaza-benzo[f]azulene] is a potential novel antipsychotic with high affinity for dopamine D2 (Ki= 6.3 nM), 5-HT(2A) (Ki= 7.3 nM), and 5-HT6 (Ki= 8.
View Article and Find Full Text PDFNat Rev Drug Discov
September 2005
In the early 1970s, evidence of the role of serotonin (5-hydroxytryptamine or 5-HT) in depression began to emerge and the hypothesis that enhancing 5-HT neurotransmission would be a viable mechanism to mediate antidepressant response was put forward. On the basis of this hypothesis, efforts to develop agents that inhibit the uptake of 5-HT from the synaptic cleft were initiated. These studies led to the discovery and development of the selective serotonin-reuptake inhibitor fluoxetine hydrochloride (Prozac; Eli Lilly), which was approved for the treatment of depression by the US FDA in 1987.
View Article and Find Full Text PDFMajor depressive disorder (MDD) poses a significant health problem and is estimated to be the third most costly and disabling disorder in the United States. Pharmacotherapy of depression has been successful, but improvements in response rates, remission rates, side effects, compliance and faster onset of therapeutic action have become prime objectives in drug development. There is considerable support for the hypothesis that dysfunctional serotonergic or noradrenergic neurotransmission may be etiological in depressed patients.
View Article and Find Full Text PDFEur Neuropsychopharmacol
January 2005
Patients with schizophrenia (Sch), schizoaffective, schizophreniform, or bipolar (BP) I disorders [Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)]; not manic or acutely psychotic [Brief Psychiatric Rating Scale (BPRS) total score < or =45]; treated with olanzapine for 1-24 months; and who had gained > or =5% of their initial body weight were examined to determine whether amantadine could attenuate weight gain or promote weight loss. Olanzapine (Olz; 5-20 mg/day) was co-administered with double-blind treatment of 100-300 mg/day amantadine (Olz+Amt, n=60) or placebo (Olz+Plc, n=65). Visit-wise analysis of weight showed that weight change from baseline [last-observation-carried-forward (LOCF)] in the Olz+Amt group was significantly different from the Olz+Plc group at weeks 8 (P=0.
View Article and Find Full Text PDFA 73-year-old white male with a 6-month history of glossodynia, unresponsive to clotrimazole troches, cevimeline, triamcinolone dental paste, paroxetine, and lorazepam presented to the dermatology clinic for consultation. Work-up revealed no oral abnormalities and no underlying systemic disorder. He denied symptoms consistent with a psychiatric disorder.
View Article and Find Full Text PDFDopaminergic dysfunction is an important pathogenetic factor for brain pathologies such as Parkinson's disease, ADHD, schizophrenia, and addiction as well as for metabolic disorders and anorexia. Dopaminergic neurons projecting from the midbrain to forebrain regions, such as the nucleus accumbens and the prefrontal cortex, regulate motor and cognitive functions and coordinate the patterned response of the organism to sensory, affective, and rewarding stimuli. In this study, we showed that dopaminergic neurotransmission is highly dependent on M4 cholinergic muscarinic receptor function.
View Article and Find Full Text PDFBackground: To assess the sensitivity of biochemical, physiological, and pharmacological markers of peripheral norepinephrine (NE) transporter (NET) function, we chronically antagonized NET by a range of doses of duloxetine [(+)-N-methyl-3-(1-naphthalenyloxy)-2 thiophenepropanamine], which blocks the NE reuptake process.
Methods And Results: Duloxetine was administered in a randomized, placebo-controlled study in 15 healthy volunteers. Plasma from duloxetine-treated subjects (ex vivo effect) dose-dependently decreased radioligand binding to human NET (maximum inhibition was 60%) (P=0.
Prim Care Companion J Clin Psychiatry
August 2000
OBJECTIVE: To test the hypothesis that reported in vitro muscarinic receptor affinity differences between olanzapine and risperidone would be reflected in peripheral solicited anticholinergic adverse event frequencies. METHOD: Data from a double-blind, randomized trial of olanzapine versus risperidone in 339 patients (age range, 18-65 years) with DSM-IV schizophrenia spectrum acute psychosis were retrospectively analyzed. Subgroups based on the median of the mean daily drug dose were constructed (olanzapine = 17 mg; olanzapine > 17 mg; risperidone = 6 mg; risperidone > 6 mg).
View Article and Find Full Text PDFClinical studies of patients with treatment-resistant depression have shown that combined treatment with fluoxetine and olanzapine rapidly and significantly improved depressive symptoms. The present study used in vivo microdialysis to investigate the brain regional and dose effects of these drugs on extracellular monoamine concentrations in the rat prefrontal cortex, hypothalamus, nucleus accumbens and striatum. In the prefrontal cortex, the olanzapine/fluoxetine combination (3/10 mg/kg, respectively) increased catecholamine concentrations to a significantly greater extent than either drug alone (dopamine mean+/-S.
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