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EFFECTS OF A SINGLE ORAL DOSE OF TRAZODONE ON BEHAVIOR AND SERUM CORTISOL LEVELS IN BLUE WILDEBEEST ( CONNOCHAETES TAURINUS). J Zoo Wildl Med 2023; 53:679-688. [PMID: 36640069 DOI: 10.1638/2021-0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2022] [Indexed: 01/09/2023] Open
Abstract
Trazodone is a dose-dependent serotonin antagonist and agonist used to treat anxiety-related conditions. Trauma has been identified as the leading cause of morbidity and mortality in several nondomestic ruminant species and can be exacerbated by stress. In a recent study in domestic goats (Capra aegagrus hircus), trazodone reduced activity levels without adverse effects. Trazodone could allow for safer capture and handling in nondomestic ruminant species. The objectives of this study were to identify a dose of trazodone that decreases activity levels in captive blue wildebeest (Connochaetes taurinus) and to evaluate its safety and its effects on serum cortisol levels following a routine veterinary procedure. A pilot study using ethograms identified a group fed 15 mg/kg oral dose of trazodone as effective to reduce activity levels. Over 6 h, this dose resulted in a 111% increase in time spent sleeping or resting (P = 0.0003), a 41% increase in time spent lying down (P = 0.0016), a 64% reduction in time spent moving (P= 0.005), and a 65% reduction in time spent being vigilant (P= 0.026). Systemic absorption of trazodone was identified when plasma concentrations were measured after 2 h (95 ± 48 µg/L). Serum cortisol levels during a routine venipuncture event were not significantly different following trazodone administration (P > 0.05). Mild hyporexia was the only adverse effect noted at 15 mg/kg and was absent at a 12 mg/kg dose. Trazodone appears safe and promising to decrease activity in blue wildebeest and might thus have a positive effect on nondomestic ruminant welfare and the safety of veterinary procedures.
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Early response to trazodone once-a-day in major depressive disorder: review of the clinical data and putative mechanism for faster onset of action. CNS Spectr 2021; 26:232-242. [PMID: 33731232 DOI: 10.1017/s1092852921000304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Most antidepressants have a delayed onset of action and must be administered for several weeks to generate therapeutic effects. Trazodone is a serotonin antagonist and reuptake inhibitor approved for the treatment of major depressive disorder. The once-a-day (OAD) formulation of trazodone has an improved tolerability profile compared to its conventional formulations. In this study, we systematically reviewed the evidence available for the antidepressant efficacy and early improvement in depressive symptoms with trazodone OAD treatment. METHOD We conducted a PubMed database search for randomized controlled trials published from 2005 to 2020. RESULTS Two studies, a placebo-controlled and an active-comparator (venlafaxine extended-release or XR) study were found. Both the studies demonstrated that trazodone exhibits antidepressant activity at a starting dose of 150 mg/day and results in statistically significant greater reduction in Hamilton Depression Rating Scale (HAM-D17) scores within 1 week of starting treatment compared to placebo or venlafaxine XR (P < .05). Trazodone also resulted in significant early improvement in the HAM-D17 sleep disturbance factor compared to placebo or venlafaxine XR at day 7 (P < .05). This clinical effect is supported by in vitro proprietary data for the affinity of trazodone for different target receptors. Activity at these receptors may underlie trazodone's fast antidepressant action. CONCLUSIONS Trazodone, if properly dosed, can be an effective antidepressant with early onset of action and good tolerability. Future studies designed to specifically evaluate onset and timing of improvement of depressive symptoms remain necessary to confirm and extend these results.
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PHARMACOKINETICS AND CLINICAL EFFECTS OF A SINGLE ORAL DOSE OF TRAZODONE IN THE DOMESTIC GOAT ( CAPRA HIRCUS) AS A MODEL FOR WILD RUMINANTS. J Zoo Wildl Med 2021; 51:896-904. [PMID: 33480570 DOI: 10.1638/2019-0242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2020] [Indexed: 11/21/2022] Open
Abstract
Trazodone is an antianxiety medication commonly used in human and veterinary medicine. Stress-related trauma is the leading cause of morbidity and mortality in wild ruminant species. Trazodone could reduce stress and allow safer capture and handling, thus having a positive effect on their welfare. The objective of this study was to describe the clinical effects and pharmacokinetic profile of an oral dose of trazodone in domestic goats (Capra hircus) as a model for wild ruminants. A pilot study using ethograms and accelerometers identified an oral dose of 10 mg/kg as optimal to reduce activity levels. This dose resulted in a 502% increase in time spent sleeping (P=0.0016) and a 623% increase in time spent lying down (P=0.01). Additionally, there were reductions of 72% in time spent grooming (P=0.02), 49% in time spent moving (P=0.01), and 87% in time spent observing (P=0.0002). Activity levels were significantly decreased by 31% for 4 hr following administration (P=0.049). There were no observed adverse effects. Time spent eating or ruminating was not affected by trazodone administration (P > 0.05). The pharmacokinetics of trazodone following a single oral dose of 10 mg/kg in 7 goats was assessed. All animals achieved plasma concentrations over 130 ng/ml, a level considered therapeutic in humans and dogs, for a mean of 6.4 ± 5.0 hr. Mean terminal half-life was 10.55 ± 6.80 hr. All goats achieved maximum concentration within 5-15 min and still had detectable plasma levels at 24 hr. Trazodone appears promising to decrease stress in exotic ruminant species. Further research is warranted to establish its efficacy in other ruminant species and clinical situations.
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O'Donnell EM, Press SA, Karriker MJ, Istvan SA. Pharmacokinetics and efficacy of trazodone following rectal administration of a single dose to healthy dogs. Am J Vet Res 2020; 81:739-746. [PMID: 33112166 DOI: 10.2460/ajvr.81.9.739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the pharmacokinetics and efficacy of trazodone following rectal administration of a single dose to healthy dogs. ANIMALS 6 healthy adult dogs. PROCEDURES Each dog received a single dose of trazodone (approx 8 mg/kg) per rectum. Trazodone tablets were crushed into a powder, mixed with 5 mL of tap water, and injected into the rectum via a red rubber catheter. Sedation scores were assigned, and blood samples were collected for determination of plasma trazodone concentration at predetermined times before and after drug administration. Pharmacokinetic parameters were estimated by noncompartmental analysis. RESULTS Plasma trazodone concentration remained below the detection limit for 1 dog even though it became moderately sedate. Median (interquartile [25th to 75th percentile] range [IQR]) maximum plasma trazodone concentration and volume of distribution and clearance corrected for bioavailability were 1.00 μg/mL (0.66 to 1.40 μg/mL), 10.3 L/kg (7.37 to 14.4 L/kg), and 639 mL/kg/h (594 to 719 mL/kg/h), respectively. Median time to maximum plasma trazodone concentration and elimination half-life were 15 minutes (range, 15 to 30 minutes) and 12 hours (IQR, 7.99 to 12.7 hours), respectively. All dogs became mildly or moderately sedate, and the extent of sedation was maximal at a median of 30 minutes (IQR, 30 to 60 minutes) after trazodone administration. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Rectal administration of trazodone may be a viable option for sedation and treatment of anxiety in dogs for which administration of sedatives and anxiolytics by other routes is contraindicated. Further research is necessary to better elucidate the pharmacokinetics and efficacy of trazodone following rectal administration and determine optimal dosing.
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Han L, Wu KLK, Kwan PY, Chua OWH, Shum DKY, Chan YS. 5-HT 1A receptor-mediated attenuation of synaptic transmission in rat medial vestibular nucleus impacts on vestibular-related motor function. J Physiol 2020; 599:253-267. [PMID: 33006159 DOI: 10.1113/jp280610] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/29/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Chemogenetic activation of medial vestibular nucleus-projecting 5-HT neurons resulted in deficits in vestibular-mediated tasks, including negative geotaxis, balance beam and rota-rod tests. The 5-HT1A receptor mediates the vestibular-related behavioural effects of 5-HT in the vestibular nucleus. 5-HT1A receptor activation attenuated evoked excitatory postsynaptic currents and evoked inhibitory postsynaptic currents via a presynaptic mechanism in the vestibular nucleus. ABSTRACT While the anxiolytic effects of serotonergic neuromodulation are well studied, its role in sensorimotor coordination and postural control is unclear. In this study, we show that an increase of serotonin (5-hydroxytryptamine, 5-HT) at the medial vestibular nucleus (MVN), a brainstem centre for vestibulospinal coordination, by either direct cannula administration or chemogenetic stimulation of MVN-projecting serotonergic neurons, adversely affected performance of rats in vestibular-mediated tasks, including negative geotaxis, balance beam and rota-rod tests. Application of the 5-HT1 and 5-HT7 receptor co-agonist 8-hydroxy-2-(di-n-propylamino) tetralin recapitulated the effect of 5-HT, while co-administration of the specific 5-HT1A receptor antagonist WAY 100135 effectively abolished all 5-HT-induced behavioural deficits. This indicated that 5-HT1A receptors mediated the effects of 5-HT in the rat MVN. Using whole-cell patch-clamp recording, we demonstrated that 5-HT1A receptor activation attenuated both evoked excitatory and evoked inhibitory postsynaptic currents through a presynaptic mechanism in the rat MVN. The results thus highlight the 5-HT1A receptor as the gain controller of vestibular-related brainstem circuits for posture and balance.
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Affiliation(s)
- Lei Han
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
| | - Kenneth Lap-Kei Wu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
| | - Pui-Yi Kwan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
| | - Oscar Wing-Ho Chua
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
| | - Daisy Kwok-Yan Shum
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China.,State Key Laboratory of Brain and Cognitive Science, The University of Hong Kong, Hong Kong, PR China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China.,State Key Laboratory of Brain and Cognitive Science, The University of Hong Kong, Hong Kong, PR China
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Cisani F, Roggeri A, Olivero G, Garrone B, Tongiani S, Di Giorgio FP, Pittaluga A. Acute Low Dose of Trazodone Recovers Glutamate Release Efficiency and mGlu2/3 Autoreceptor Impairments in the Spinal Cord of Rats Suffering From Chronic Sciatic Ligation. Front Pharmacol 2020; 11:1108. [PMID: 32765286 PMCID: PMC7379891 DOI: 10.3389/fphar.2020.01108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/08/2020] [Indexed: 11/16/2022] Open
Abstract
We investigated whether chronic sciatic ligation modifies the glutamate release in spinal cord nerve endings (synaptosomes) as well as the expression and the function of presynaptic release-regulating mGlu2/3 autoreceptors and 5-HT2A heteroreceptors in these particles. Synaptosomes were from the spinal cord of animals suffering from the sciatic ligation that developed on day 6 post-surgery a significant decrease of the force inducing paw-withdrawal in the lesioned paw. The exocytosis of glutamate (quantified as release of preloaded [3H]D-aspartate, [3H]D-Asp) elicited by a mild depolarizing stimulus (15 mM KCl) was significantly increased in synaptosomes from injured rats when compared to controls (uninjured rats). The mGlu2/3 agonist LY379268 (1000 pM) significantly inhibited the 15 mM KCl-evoked [3H]D-Asp overflow from control synaptosomes, but not in terminals isolated from injured animals. Differently, a low concentration (10 nM) of (±) DOI, unable to modify the 15 mM KCl-evoked [3H]D-Asp overflow in control spinal cord synaptosomes, significantly reduced the glutamate exocytosis in nerve endings isolated from the injured rats. Acute oral trazodone (TZD, 0.3 mg/kg on day 7 post-surgery) efficiently recovered glutamate exocytosis as well as the efficiency of LY379268 in inhibiting this event in spinal cord synaptosomes from injured animals. The sciatic ligation significantly reduced the expression of mGlu2/3, but not of 5-HT2A, receptor proteins in spinal cord synaptosomal lysates. Acute TZD recovered this parameter. Our results support the use of 5-HT2A antagonists for restoring altered spinal cord glutamate plasticity in rats suffering from sciatic ligation.
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Affiliation(s)
- Francesca Cisani
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Alessandra Roggeri
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Beatrice Garrone
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | - Serena Tongiani
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | | | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
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Canal CE. Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. Handb Exp Pharmacol 2019; 252:227-260. [PMID: 29532180 PMCID: PMC6136989 DOI: 10.1007/164_2018_107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.
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Affiliation(s)
- Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA.
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Desmarchelier MR, Beaudry F, Ferrell ST, Frank D. Determination of the pharmacokinetics of a single oral dose of trazodone and its effect on the activity level of domestic pigeons (Columba livia). Am J Vet Res 2019; 80:102-109. [PMID: 30605036 DOI: 10.2460/ajvr.80.1.102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the pharmacokinetics of a single oral dose of trazodone and its effect on the activity of domestic pigeons (Columba livia). ANIMALS 6 healthy adult male domestic pigeons. PROCEDURES During the first of 3 experiments, birds received orally administered trazodone at doses ranging from 3 to 30 mg/kg to determine the dose for subsequent experiments. During the second experiment, each bird received 1 dose of trazodone (30 mg/kg, PO). Blood was collected for determination of plasma trazodone concentration before and at predetermined times for 24 hours after drug administration. Pharmacokinetic parameters were calculated by noncompartmental analysis. During experiment 3, birds were instrumented with ultralightweight accelerometers and received orally administered trazodone (30 mg/kg) or an equal volume of water twice at a 48-hour interval. Activity of birds was monitored for 24 hours after administration of each treatment. RESULTS No adverse effects were observed. Mean ± SD terminal half-life of trazodone was 5.65 ± 1.75 hours. Plasma trazodone concentrations remained > 0.130 μg/mL for approximately 20 hours. Trazodone did not affect the activity of birds during the first 2 and 15 hours after administration. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that oral administration of 1 dose (30 mg/kg) of trazodone to healthy pigeons was safe and resulted in plasma drug concentrations that were similar to those considered therapeutic in humans and dogs for up to 20 hours. Further research is necessary to characterize the pharmacokinetics for repeated doses as well as the clinical effects of trazodone in birds with behavior problems.
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Hoffman EA, Aarnes TK, Ricco Pereira CH, Lerche P, Bednarski RM, McLoughlin MA. Effect of oral trazodone on the minimum alveolar concentration of isoflurane in dogs. Vet Anaesth Analg 2018; 45:754-759. [PMID: 30297130 DOI: 10.1016/j.vaa.2018.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the effect of oral trazodone on the minimum alveolar concentration (MAC) of isoflurane in dogs. STUDY DESIGN Prospective blinded, single-observer, randomized crossover experimental study. ANIMALS Six adult (age 6.8 ± 1.6 months) healthy dogs (three males and three females), weighing 24.8 ± 3.4 kg (mean ± standard deviation). METHODS Each dog was anesthetized twice with a minimum of 7 days between anesthetic episodes. Dogs were randomly assigned to be administered two treatments in a crossover design: premedication with trazodone (8 mg kg-1; TRAZ-ISO) orally 2 hours prior to an anesthetic episode or no (ISO). Dogs were anesthetized with intravenous propofol (6 mg kg-1) and isoflurane in >95% oxygen. Isoflurane MAC was determined using an iterative bracketing technique with electrodes placed in the buccal mucosa. Hemodynamic variables were compared at the lowest end-tidal isoflurane concentration at which each dog did not respond. A paired t test was used to assess the effect of treatment on outcome variables with significance set to a value of p < 0.05. RESULTS The MAC concentration (mean ± standard deviation) in dogs administered TRAZ-ISO was 0.85 ± 0.17% compared with 1.02 ± 0.11% in those administered ISO (p = 0.01, 95% confidence interval -0.25 to -0.05), resulting in a mean MAC reduction of 17 ± 12%. There were no differences in hemodynamic variables between treatments. CONCLUSIONS AND CLINICAL RELEVANCE Premedication of dogs with oral trazodone (8 mg kg-1) 2 hours prior to anesthetic induction has a significant isoflurane MAC sparing effect with no significant observed hemodynamic benefit.
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Affiliation(s)
- Elizabeth A Hoffman
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Turi K Aarnes
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
| | - Carolina H Ricco Pereira
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Phillip Lerche
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Richard M Bednarski
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Mary A McLoughlin
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
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Hautzel H, Müller HW, Nikolaus S. Focus on GABAA receptor function. Nuklearmedizin 2018; 53:227-37. [DOI: 10.3413/nukmed-0647-14-03] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 08/21/2014] [Indexed: 12/31/2022]
Abstract
SummaryImpairment of GABAA receptor function is increasingly recognized to play a major role in the pathophysiology of neuropsychiatric diseases including anxiety disorder (AD), major depressive disorder (MDD) and schizophrenia (SZ). Patients, method: We conducted a PUBMED search, which provided a total of 23 in vivo investigations with PET and SPECT, in which GABAA receptor binding in patients with the primary diagnosis of AD (n = 14, 160 patients, 172 controls), MDD (n = 2, 24 patients, 28 controls) or SZ (n = 6, 77 patients, 90 controls) was compared to healthy individuals. Results: A retrospective analysis revealed that AD, MDD and SZ differed as to both site(s) and extent(s) of GABAergic impairment. Additionally, it may be stated that, while the decline of GABAA receptor binding AD involved the whole mesolimbocortical system, in SZ it was confined to the frontal and temporal cortex. Conclusion: As GABA is known to inhibit dopamine and serotonin, GABAergic dysfunction may be associated with the disturbances of dopaminergic and serotonergic neurotransmission in neuropsychiatric disorders.
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Settimo L, Taylor D. Evaluating the dose-dependent mechanism of action of trazodone by estimation of occupancies for different brain neurotransmitter targets. J Psychopharmacol 2018; 32:96-104. [PMID: 29332554 DOI: 10.1177/0269881117742101] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Trazodone is a drug that was introduced in the clinic almost 40 years ago. It is licensed to treat depression, but it is also commonly used off-label to treat insomnia. A recent study shows that it could be promising in preventing neurodegeneration in mice, and clinical trials to assess its possible beneficial effects on dementia and Alzheimer's disease are expected to start soon in humans. In this study, we describe the dose-dependent pharmacology of trazodone by carrying out pharmacokinetic simulations aiming to predict the brain concentrations of trazodone for different drug-dosing regimens and calculating occupancy for 28 different targets for which published trazodone-binding data are available. Our study indicates that low doses of trazodone (typically 50 mg daily) should suffice to block specific receptors responsible for the hypnotic effect, and to provide the protective effect against neuroinflammation and neurodegeneration that could be beneficial in dementia. Higher doses are required for an antidepressant effect. The occupancy of specific receptors at therapeutic doses also explains peculiar side effects reported by patients treated with trazodone (e.g. dry-mouth, hypotension and priapism).
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Affiliation(s)
- Luca Settimo
- 1 Pharmacy Department, Prospect Park Hospital, Reading, UK
| | - David Taylor
- 2 Pharmacy Department, Maudsley Hospital, London, UK.,3 Institute of Pharmaceutical Science, King's College, London, UK
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Murphy LA, Barletta M, Graham LF, Reichl LJ, Duxbury MM, Quandt JE. Effects of acepromazine and trazodone on anesthetic induction dose of propofol and cardiovascular variables in dogs undergoing general anesthesia for orthopedic surgery. J Am Vet Med Assoc 2017; 250:408-416. [DOI: 10.2460/javma.250.4.408] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Nikolaus S, Müller HW, Hautzel H. Different patterns of 5-HT receptor and transporter dysfunction in neuropsychiatric disorders--a comparative analysis of in vivo imaging findings. Rev Neurosci 2016; 27:27-59. [PMID: 26376220 DOI: 10.1515/revneuro-2015-0014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/05/2015] [Indexed: 11/15/2022]
Abstract
Impairment of serotonin receptor and transporter function is increasingly recognized to play a major role in the pathophysiology of neuropsychiatric diseases including anxiety disorder (AD), major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ). We conducted a PubMed search, which provided a total of 136 in vivo studies with PET and SPECT, in which 5-HT synthesis, 5-HT transporter binding, 5-HT1 receptor binding or 5-HT2 receptor binding in patients with the primary diagnosis of acute AD, MDD, BD or SZ was compared to healthy individuals. A retrospective analysis revealed that AD, MDD, BD and SZ differed as to affected brain region(s), affected synaptic constituent(s) and extent as well as direction of dysfunction in terms of either sensitization or desensitization of transporter and receptor binding sites.
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15
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Tang Y, Zhang T, Edelman B, Zeng B, Zhao S, Li C, Zhuo K, Qian Z, Li H, Guo Q, Cui H, Zhu Y, Jiang L, Li C, Yu D, Wang J. Prolonged cortical silent period among drug-naive subjects at ultra-high risk of psychosis. Schizophr Res 2014; 160:124-30. [PMID: 25458861 DOI: 10.1016/j.schres.2014.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/09/2014] [Accepted: 10/07/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Deficits in gamma-aminobutyric acid (GABA) inhibitory neurotransmission have been associated with pathophysiological mechanisms underlying schizophrenia. However, little is known about whether these deficits occur before or after the onset of psychosis. METHOD We recruited 16 drug-naive subjects at ultra-high risk of psychosis (UHR), 17 schizophrenia patients and 28 healthy controls. Cortical inhibition was determined using transcranial magnetic stimulation (TMS) over the left primary motor cortex. TMS markers such as short-interval cortical inhibition (SICI), cortical silent period (CSP) and intracortical facilitation (ICF) were obtained from each subject. While SICI can reflect GABA type A (GABAA) mediated inhibition, CSP is thought to indicate GABA type B (GABAB) mediated inhibitory circuits. RESULTS As compared with healthy controls, UHR subjects showed a prolonged CSP with no change in SICI, whereas schizophrenia patients demonstrated both a prolonged CSP and a reduced SICI. No group differences were found for ICF. CSP in schizophrenia patients also had a positive correlation with positive symptom score of the positive and negative symptom scale (PANSS). CONCLUSIONS Cortical inhibitory deficits among UHR subjects were relatively limited compared to those among schizophrenia patients. Alterations might occur in some subgroup of GABA-mediated neurotransmitter systems before the onset of psychosis, while alterations in both GABAA and GABAB networks might contribute to full-blown psychosis.
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Affiliation(s)
- Yingying Tang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China; Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Tianhong Zhang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China; Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Bradley Edelman
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Botao Zeng
- Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Shanshan Zhao
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Chunyan Li
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Kaiming Zhuo
- Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Zhenying Qian
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Hui Li
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Qian Guo
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Huiru Cui
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Yikang Zhu
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Lijuan Jiang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Chunbo Li
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China; Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Dehua Yu
- Department of Psychiatry, Yangpu Hospital, Medical School of Tongji University, Shanghai 200090, PR China.
| | - Jijun Wang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China; Department of EEG and Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China.
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Nikolaus S, Hautzel H, Müller HW. Neurochemical dysfunction in treated and nontreated schizophrenia - a retrospective analysis of in vivo imaging studies. Rev Neurosci 2014; 25:25-96. [PMID: 24486731 DOI: 10.1515/revneuro-2013-0063] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 12/26/2013] [Indexed: 12/22/2022]
Abstract
To evaluate the contribution of individual synaptic constituents, all available in vivo imaging studies on schizophrenic patients were subjected to a retrospective analysis. For the pool of drug-naïve, drug-free, and acutely medicated patients, major findings were increases in neostriatal dopamine (DA) synthesis and release and decreases in neostriatal DA transporters and D1 receptors, neostriatal, thalamic, frontal, and parietal D2 receptors, mesencephalic/pontine and temporal 5-HT1A receptors, frontal and temporal HT2A and μ-amino butyric acid (GABA)A receptors. Based on the findings on drug-naïve and drug-free patients, it may be hypothesized that schizophrenia initially is characterized by an impaired mechanism of D2 autoreceptor and heteroreceptor sensitization leading to sensitization instead of desensitization in response to increased levels of neostriatal DA. Neuroleptic medication blocks neostriatal D2 autoreceptor and heteroreceptors, reducing neostriatal DA and disinhibiting DA action mediated by D2 heteroreceptor binding sites. Ultimately, this may result in a restitution of GABA function, leading to a recovery of inhibitory input to the target regions of the descending corticothalamostriatal efferents. Furthermore, a blockade of inhibitory and excitatory neocortical 5-HT function may be inferred, which is likely to reduce (excitatory) DAergic input to the mesolimbic target regions of corticothalamostriatal projections.
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17
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Mittur A. Trazodone: properties and utility in multiple disorders. Expert Rev Clin Pharmacol 2014; 4:181-96. [DOI: 10.1586/ecp.10.138] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Serotonergic modulation of LTP at excitatory and inhibitory synapses in the developing rat visual cortex. Neuroscience 2013; 238:148-58. [DOI: 10.1016/j.neuroscience.2013.02.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/06/2013] [Accepted: 02/08/2013] [Indexed: 11/21/2022]
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Christensen T, Bétry C, Mnie-Filali O, Etievant A, Ebert B, Haddjeri N, Wiborg O. Synergistic antidepressant-like action of gaboxadol and escitalopram. Eur Neuropsychopharmacol 2012; 22:751-60. [PMID: 22406239 DOI: 10.1016/j.euroneuro.2012.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 12/21/2011] [Accepted: 02/04/2012] [Indexed: 11/28/2022]
Abstract
According to current theories on the etiopathogenesis and pathophysiology of depression, both GABAergic and monoaminergic transmitter systems are perturbed. Consequently, the present study addressed the putative antidepressant action of the sedative-hypnotic GABAA receptor agonist, gaboxadol, separately and in combination with the selective serotonin reuptake inhibitor (SSRI) escitalopram. The rat chronic mild stress model was used to test the chronic antidepressant properties of gaboxadol in this depression model. Sucrose intake used as a read-out on anhedonic-like behavior indicated that the drug response rate for gaboxadol (5 mg/kg/day, i.p.) was similar to that measured for escitalopram (5 mg/kg/day, i.p.), however, the rate increased when the two drugs were co-administered, suggesting a synergistic action. Using in vivo electrophysiological recordings in dorsal raphe nucleus (DRN) of anesthetised rats, the present results showed that one week treatment with gaboxadol (5 mg/kg/day, i.p.) or with escitalopram (5 mg/kg/day, i.p.), followed by a 24 h washout period, did not affect DRN 5-HT neuronal firing per se, but in rats treated with both drugs for one week, the firing rate of DRN 5-HT neurons was significantly increased. Immunohistochemical estimations of cell proliferation in the hippocampal dentate gyrus did not reveal any effect of gaboxadol on chronic mild stressed rats, indicating that neurogenesis per se is not systematically associated with recovery from anhedonic-like behavior. Taken together, our data reveal for the first time an antidepressant action of gaboxadol and indicate a synergistic mechanism, regarding rapid onset of action and efficacy, when co-administered with escitalopram.
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Affiliation(s)
- Trine Christensen
- Centre for Psychiatric Research, Aarhus University Hospital, Skovagervej 2, 8240 Risskov, Denmark
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20
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Drueke B, Boecker M, Schlaegel S, Moeller O, Hiemke C, Gründer G, Gauggel S. Serotonergic modulation of response inhibition and re-engagement? Results of a study in healthy human volunteers. Hum Psychopharmacol 2010; 25:472-80. [PMID: 20737520 DOI: 10.1002/hup.1141] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Cognitive functions dependent on the prefrontal cortex, such as the ability to suppress behavior (response inhibition) and initiate a new one (response re-engagement) is important in the activities of daily life. Central serotonin (5-HT) function is thought to be a critical component of these cognitive functions. In recent studies, 5-HT failed to affect stop-signal reaction time (SSRT), a fundamental process in behavioral inhibition. We were interested if response inhibition and re-engagement are influenced through central 5-HT activity as mediated via the 5-HT transporter. METHODS Here, using a stop-change task, we investigated the effects of acute and repeated treatment with 10 mg escitalopram, a selective 5-HT reuptake inhibitor, in 36 healthy human volunteers on response inhibition and re-engagement in a randomized, double-blind, placebo-controlled study with cross-over design. RESULTS Results do not show an influence of escitalopram on response inhibition or response re-engagement as we did not find differences in SSRT or change reaction time (CRT). CONCLUSIONS These findings support the results of previous studies suggesting that 5-HT is not critical in inhibition of already initiated responses and response re-engagement. We hypothesize that results are due to different forms of behavioral inhibition and 5-HT may critical to other forms.
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Affiliation(s)
- Barbara Drueke
- Department of Medical Psychology and Medical Sociology, RWTH Aachen University, Pauwelsstrasse, Germany.
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21
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Moreau AW, Amar M, Le Roux N, Morel N, Fossier P. Serotoninergic fine-tuning of the excitation-inhibition balance in rat visual cortical networks. ACTA ACUST UNITED AC 2009; 20:456-67. [PMID: 19520765 DOI: 10.1093/cercor/bhp114] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Fundamental brain functions depend on a balance between excitation (E) and inhibition (I) that is highly adjusted to a 20-80% set point in layer 5 pyramidal neurons (L5PNs) of rat visual cortex. Dysregulations of both the E-I balance and the serotonergic system in neocortical networks lead to serious neuronal diseases including depression, schizophrenia, and epilepsy. However, no link between the activation of neuronal 5-hydroxytryptamine receptors (5-HTRs) and the cortical E-I balance has yet been reported. Here we used a combination of patch-clamp recordings of composite stimulus-locked responses in L5PN following local electrical stimulations in either layer 2/3 or 6, simultaneous measurement of excitatory and inhibitory conductance dynamics, together with selective pharmacological targeting and single-cell reverse transcriptase-polymerase chain reaction. We show that cortical serotonin shifts the E-I balance in favor of more E and we reveal fine and differential modulations of the E-I balance between 5-HTR subtypes, in relation to whether layer 2/3 or 6 was stimulated and in concordance with the specific expression pattern of these subtypes in pyramidal cells and deep interneurons. This first evidence for the functional segregation of 5-HTR subtypes sheds new light on their coherent functioning in polysynaptic sensory circuits.
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Affiliation(s)
- Alexandre William Moreau
- CNRS, Institut de Neurobiologie Alfred Fessard-FRC2118, Laboratoire de Neurobiologie Cellulaire et Moléculaire-UPR9040, F-91198 Gif sur Yvette, France
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22
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Roth T. Hypnotic use for insomnia management in chronic obstructive pulmonary disease. Sleep Med 2009; 10:19-25. [DOI: 10.1016/j.sleep.2008.06.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/31/2008] [Accepted: 06/17/2008] [Indexed: 11/17/2022]
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Gruen ME, Sherman BL. Use of trazodone as an adjunctive agent in the treatment of canine anxiety disorders: 56 cases (1995–2007). J Am Vet Med Assoc 2008; 233:1902-7. [DOI: 10.2460/javma.233.12.1902] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Calabrese EJ. An Assessment of Anxiolytic Drug Screening Tests: Hormetic Dose Responses Predominate. Crit Rev Toxicol 2008; 38:489-542. [DOI: 10.1080/10408440802014238] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Abstract
OBJECTIVE Many patients with depression suffer from sexual dysfunction and sexual dysfunction is a recognized side-effect of antidepressants. The aim of this review was to examine the prevalence of psychosexual dysfunction associated with antidepressants, and to review treatment options which are specific to the affected component of sexual functioning and antidepressants. METHOD Comprehensive literature review using Medline and Cochrane databases. RESULTS Up to 70% of patients with depression may have sexual dysfunction. Tricyclic antidepressants, selective-serotonin reuptake inhibitors and venlafaxine are most and the non-serotonergic antidepressants and duloxetine least likely to produce sexual dysfunction. Pharmacological treatment options include antidepressants less likely associated or 'antidotes' to reverse sexual dysfunction. CONCLUSION Sexual dysfunction may be a preventable or treatable side-effect of antidepressants. Patients need routinely to be asked about sexual function to identify problems early. If sexual dysfunction is ignored it may maintain the depression, compromise treatment outcome and lead to non-compliance.
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Affiliation(s)
- U Werneke
- Department of Psychiatry, Homerton University Hospital, London, UK. [corrected]
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28
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Davis MP. Does trazodone have a role in palliating symptoms? Support Care Cancer 2006; 15:221-4. [PMID: 17131134 DOI: 10.1007/s00520-006-0111-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 06/14/2006] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Trazodone is a unique antidepressant, which blocks the postsynaptic serotonin (5-HT) receptors, 5-HT(2A) and 5-HT(2C), and weakly inhibits presynaptic 5-HT transporters. DISCUSSION Trazodone is well-absorbed by the mouth and is metabolized by three cytochromes: CYP1A2, CYP2D6, and CYP3A4. Clinical benefits include reduced insomnia in those depressed and/or on antidepressants. Pain may be relieved by mechanisms similar to venlafaxine. Delirium unresponsive to neuroleptics has been reported to respond to trazodone. Drug interactions are a risk due to cytochrome metabolism. CONCLUSION Trazodone has a unique pharmacology, which may be an advantage in palliating symptoms; however, little evidence is available through cohort or randomized trials to give guidance to its use.
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Affiliation(s)
- Mellar P Davis
- The Harry R Horvitz Center for Palliative Medicine, Cleveland Clinic Foundation, M76, Cleveland, OH 44195, USA.
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Li Y, Peris J, Zhong L, Derendorf H. Microdialysis as a tool in local pharmacodynamics. AAPS JOURNAL 2006; 8:E222-35. [PMID: 16796373 PMCID: PMC3231563 DOI: 10.1007/bf02854892] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In many cases the clinical outcome of therapy needs to be determined by the drug concentration in the tissue compartment in which the pharmacological effect occurs rather than in the plasma. Microdialysis is an in vivo technique that allows direct measurement of unbound tissue concentrations and permits monitoring of the biochemical and physiological effects of drugs throughout the body. Microdialysis was first used in pharmacodynamic research to study neurotransmission, and this remains its most common application in the field. In this review, we give an overview of the principles, techniques, and applications of microdialysis in pharmacodynamic studies of local physiological events, including measurement of endogenous substances such as acetylcholine, catecholamines, serotonin, amino acids, peptides, glucose, lactate, glycerol, and hormones. Microdialysis coupled with systemic drug administration also permits the more intensive examination of the pharmacotherapeutic effect of drugs on extracellular levels of endogenous substances in peripheral compartments and blood. Selected examples of the physiological effects and mechanisms of action of drugs are also discussed, as are the advantages and limitations of this method. It is concluded that microdialysis is a reliable technique for the measurement of local events, which makes it an attractive tool for local pharmacodynamic research.
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Affiliation(s)
- Yanjun Li
- />Department of Pharmaceutics, University of Florida, PO Box 100494, College of Pharmacy, 32610 Gainesville, FL
| | - Joanna Peris
- />Department of Pharmacodynamics, College of Pharmacy, University of Florida, 32610 Gainesville, FL
| | - Li Zhong
- />Department of Pediatrics, College of Medicine, University of Florida, 32610 Gainesville, FL
| | - Hartmut Derendorf
- />Department of Pharmaceutics, University of Florida, PO Box 100494, College of Pharmacy, 32610 Gainesville, FL
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Ducray A, Krebs SH, Schaller B, Seiler RW, Meyer M, Widmer HR. GDNF family ligands display distinct action profiles on cultured GABAergic and serotonergic neurons of rat ventral mesencephalon. Brain Res 2006; 1069:104-12. [PMID: 16380100 DOI: 10.1016/j.brainres.2005.11.056] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 11/08/2005] [Accepted: 11/11/2005] [Indexed: 12/29/2022]
Abstract
Glial-cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN), known as the GDNF family ligands (GFLs), influence the development, survival and differentiation of cultured dopaminergic neurons from ventral mesencephalon (VM). Detailed knowledge about the effects of GFLs on other neuronal populations in the VM is essential for their potential application as therapeutic molecules for Parkinson's disease. Hence, in a comparative study, we investigated the effects of GFLs on cell densities and morphological differentiation of gamma-aminobutyric acid-immunoreactive (GABA-ir) and serotonin-ir (5-HT-ir) neurons in primary cultures of E14 rat VM. We observed that all GFLs [10 ng/ml] significantly increased GABA-ir cell densities (1.6-fold) as well as neurite length/neuron. However, only GDNF significantly increased the number of primary neurites/neuron, and none of the GFLs affected soma size of GABA-ir neurons. In contrast, only NRTN treatment significantly increased 5-HT-ir cells densities at 10 ng/ml (1.3-fold), while an augmentation was seen for GDNF and PSPN at 100 ng/ml (2.4-fold and 1.7-fold, respectively). ARTN had no effect on 5-HT-ir cell densities. Morphological analysis of 5-HT-ir neurons revealed a significant increase of soma size, number of primary neurites/neuron and neurite length/neuron after GDNF exposure, while PSPN only affected soma size, and NRTN and ARTN failed to exert any effect. In conclusion, we identified GFLs as effective neurotrophic factors for VM GABAergic and serotonergic neurons, demonstrating characteristic individual action profiles emphasizing their important and distinct roles during brain development.
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Affiliation(s)
- Angélique Ducray
- Department of Neurosurgery, University of Bern, CH-3010 Bern, Switzerland
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