51
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de Leon J, Ruan CJ, Schoretsanitis G, De las Cuevas C. A Rational Use of Clozapine Based on Adverse Drug Reactions, Pharmacokinetics, and Clinical Pharmacopsychology. PSYCHOTHERAPY AND PSYCHOSOMATICS 2020; 89:200-214. [PMID: 32289791 PMCID: PMC7206357 DOI: 10.1159/000507638] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Using Richardson and Davidson's model and the sciences of pharmacokinetics and clinical pharmacopsychology, this article reviewed the: (1) poor life expectancy associated with treatment-resistant schizophrenia (TRS), which may be improved in patients who adhere to clozapine; (2) findings that clozapine is the best treatment for TRS (according to efficacy, effectiveness and well-being); and (3) potential for clozapine to cause vulnerabilities, including potentially lethal adverse drug reactions such as agranulocytosis, pneumonia, and myocarditis. Rational use requires: (1) modification of the clozapine package insert worldwide to include lower doses for Asians and to avoid the lethality associated with pneumonia, (2) the use of clozapine levels for personalizing dosing, and (3) the use of slow and personalized titration. This may make clozapine as safe as possible and contribute to increased life expectancy and well-being. In the absence of data on COVID-19 in clozapine patients, clozapine possibly impairs immunological mechanisms and may increase pneumonia risk in infected patients. Psychiatrists should call their clozapine patients and families and explain to them that if the patient develops fever or flu-like symptoms, the psychiatrist should be called and should consider halving the clozapine dose. If the patient is hospitalized with pneumonia, the treating physician needs to assess for symptoms of clozapine intoxication since halving the dose may not be enough for all patients; consider decreasing it to one-third or even stopping it. Once the signs of inflammation and fever have disappeared, the clozapine dose can be slowly increased to the prior dosage level.
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Affiliation(s)
- Jose de Leon
- Mental Health Research Center at Eastern State Hospital, Lexington, Kentucky, USA, .,Psychiatry and Neurosciences Research Group (CTS-549), Institute of Neurosciences, University of Granada, Granada, Spain, .,Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apóstol Hospital, University of the Basque Country, Vitoria, Spain,
| | - Can-Jun Ruan
- The National Clinical Research Centre for Mental Disorders, Beijing Key Laboratory of Mental Disorders, and Laboratory of Clinical Psychopharmacology, Beijing Anding Hospital, Capital Medical University, Beijing, China,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Georgios Schoretsanitis
- Department of Psychiatry, Zucker Hillside Hospital, Northwell Health, Glen Oaks, New York, USA
| | - Carlos De las Cuevas
- Department of Internal Medicine, Dermatology and Psychiatry, University of La Laguna, San Cristóbal de La Laguna, Spain
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52
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Dal Santo F, Jarratt-Barnham I, González-Blanco L, García-Portilla MP, Bobes J, Fernández-Egea E. Longitudinal effects of clozapine concentration and clozapine to N-desmethylclozapine ratio on cognition: A mediation model. Eur Neuropsychopharmacol 2020; 33:158-163. [PMID: 32057590 DOI: 10.1016/j.euroneuro.2020.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/08/2020] [Accepted: 01/26/2020] [Indexed: 11/20/2022]
Abstract
Previous cross-sectional studies have found clozapine to N-desmethylclozapine (CLZ:NDMC) ratio to be negatively correlated with cognition in clozapine-treated patients with schizophrenia. However, no work has examined the association between CLZ:NDMC ratio and cognition using a within-subjects design. Here, we investigate the longitudinal effects of changes in the clozapine load and the CLZ:NDMC ratio on cognition whilst controlling for a range of independent factors. We analyzed data from a cohort of seventeen clozapine-treated patients who have been repeatedly assessed with the Brief Assessment of Cognition for Schizophrenia (BACS). The Positive symptoms sub-score of the Clinical Global Impression for Schizophrenia (CGI-P) was used to assess severity of psychosis. Blood samples were collected to measure the plasmatic levels of clozapine (CLZ) and of N-desmethylclozapine, allowing calculation of the CLZ:NDMC ratio. Our analyses included bivariate and partial correlations, along with a mediation model analysis. We found that both plasmatic levels of CLZ and the CLZ:NDMC ratio were negatively correlated with cognitive performance, and that these associations were independent of changes in both daily clozapine dose and severity of psychotic symptoms. Mediation analyses further revealed the association between CLZ concentration and cognition to be partially mediated by changes in the CLZ:NDMC ratio. This is the first longitudinal analysis of the influence of CLZ concentration and CLZ:NDMC ratio on cognition. Our findings suggest that reduction of CLZ concentration and the CLZ:NDMC ratio might favorably affect cognition. Thus, the CLZ:NDMC ratio may represent a promising target for novel therapeutic strategies aiming to ameliorate cognitive impairment in clozapine-treated patients.
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Affiliation(s)
- Francesco Dal Santo
- Servicio de Salud del Principado de Asturias (SESPA), Oviedo, Spain; Área de Psiquiatría, Universidad de Oviedo, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), Oviedo, Spain; Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Isaac Jarratt-Barnham
- Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Leticia González-Blanco
- Servicio de Salud del Principado de Asturias (SESPA), Oviedo, Spain; Área de Psiquiatría, Universidad de Oviedo, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), Oviedo, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - María Paz García-Portilla
- Servicio de Salud del Principado de Asturias (SESPA), Oviedo, Spain; Área de Psiquiatría, Universidad de Oviedo, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), Oviedo, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - Julio Bobes
- Servicio de Salud del Principado de Asturias (SESPA), Oviedo, Spain; Área de Psiquiatría, Universidad de Oviedo, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), Oviedo, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Spain
| | - Emilio Fernández-Egea
- Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK; Cambridgeshire and Peterborough NHS Foundation Trust, 128 Tenison Road, CB1 2DP Cambridge, UK.
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53
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Jovanović M, Vučićević K, Miljković B. Understanding variability in the pharmacokinetics of atypical antipsychotics - focus on clozapine, olanzapine and aripiprazole population models. Drug Metab Rev 2020; 52:1-18. [PMID: 32008418 DOI: 10.1080/03602532.2020.1717517] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Antipsychotic medicines are widely used for the management of psychotic symptoms regardless of the underlying diagnosis. Most atypical antipsychotics undergo extensive metabolism prior to excretion. Various factors may influence their pharmacokinetics, particularly elimination, leading to highly variable drug concentrations between individual patients following the same dosing regimen. Population pharmacokinetic approach, based on nonlinear mixed effects modeling, is a useful tool to identify covariates explaining pharmacokinetic variability, as well as to characterize and distinguish unexplained residual and between-subject (interindividual) variability. In addition, this approach allows the use of both sparsely and intensively sampled data. In this paper, we reviewed the pharmacokinetic characteristics of clozapine, olanzapine and aripiprazole, focusing on a population modeling approach. In particular, models based on a nonlinear mixed effects approach performed by NONMEM® software in order to identify and quantify sources of pharmacokinetic variability are presented. Population models were identified through systematic searches of PubMed and sixteen studies were selected. Some of the factors identified that significantly contribute to variability in elimination among clozapine, olanzapine, and aripiprazole are demographic characteristics, body weight, genetic polymorphism, smoking and in some cases drug interactions. Scientific research based on pharmacometric modeling is useful to further characterize sources of variability and their combined effect.
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Affiliation(s)
- Marija Jovanović
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
| | - Katarina Vučićević
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
| | - Branislava Miljković
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
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54
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Barnes TR, Drake R, Paton C, Cooper SJ, Deakin B, Ferrier IN, Gregory CJ, Haddad PM, Howes OD, Jones I, Joyce EM, Lewis S, Lingford-Hughes A, MacCabe JH, Owens DC, Patel MX, Sinclair JM, Stone JM, Talbot PS, Upthegrove R, Wieck A, Yung AR. Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology. J Psychopharmacol 2020; 34:3-78. [PMID: 31829775 DOI: 10.1177/0269881119889296] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.
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Affiliation(s)
- Thomas Re Barnes
- Emeritus Professor of Clinical Psychiatry, Division of Psychiatry, Imperial College London, and Joint-head of the Prescribing Observatory for Mental Health, Centre for Quality Improvement, Royal College of Psychiatrists, London, UK
| | - Richard Drake
- Clinical Lead for Mental Health in Working Age Adults, Health Innovation Manchester, University of Manchester and Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
| | - Carol Paton
- Joint-head of the Prescribing Observatory for Mental Health, Centre for Quality Improvement, Royal College of Psychiatrists, London, UK
| | - Stephen J Cooper
- Emeritus Professor of Psychiatry, School of Medicine, Queen's University Belfast, Belfast, UK
| | - Bill Deakin
- Professor of Psychiatry, Neuroscience & Psychiatry Unit, University of Manchester and Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
| | - I Nicol Ferrier
- Emeritus Professor of Psychiatry, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Catherine J Gregory
- Honorary Clinical Research Fellow, University of Manchester and Higher Trainee in Child and Adolescent Psychiatry, Manchester University NHS Foundation Trust, Manchester, UK
| | - Peter M Haddad
- Honorary Professor of Psychiatry, Division of Psychology and Mental Health, University of Manchester, UK and Senior Consultant Psychiatrist, Department of Psychiatry, Hamad Medical Corporation, Doha, Qatar
| | - Oliver D Howes
- Professor of Molecular Psychiatry, Imperial College London and Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Ian Jones
- Professor of Psychiatry and Director, National Centre of Mental Health, Cardiff University, Cardiff, UK
| | - Eileen M Joyce
- Professor of Neuropsychiatry, UCL Queen Square Institute of Neurology, London, UK
| | - Shôn Lewis
- Professor of Adult Psychiatry, Faculty of Biology, Medicine and Health, The University of Manchester, UK, and Mental Health Academic Lead, Health Innovation Manchester, Manchester, UK
| | - Anne Lingford-Hughes
- Professor of Addiction Biology and Honorary Consultant Psychiatrist, Imperial College London and Central North West London NHS Foundation Trust, London, UK
| | - James H MacCabe
- Professor of Epidemiology and Therapeutics, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, and Honorary Consultant Psychiatrist, National Psychosis Service, South London and Maudsley NHS Foundation Trust, Beckenham, UK
| | - David Cunningham Owens
- Professor of Clinical Psychiatry, University of Edinburgh. Honorary Consultant Psychiatrist, Royal Edinburgh Hospital, Edinburgh, UK
| | - Maxine X Patel
- Honorary Clinical Senior Lecturer, King's College London, Institute of Psychiatry, Psychology and Neuroscience and Consultant Psychiatrist, Oxleas NHS Foundation Trust, London, UK
| | - Julia Ma Sinclair
- Professor of Addiction Psychiatry, Faculty of Medicine, University of Southampton, Southampton, UK
| | - James M Stone
- Clinical Senior Lecturer and Honorary Consultant Psychiatrist, King's College London, Institute of Psychiatry, Psychology and Neuroscience and South London and Maudsley NHS Trust, London, UK
| | - Peter S Talbot
- Senior Lecturer and Honorary Consultant Psychiatrist, University of Manchester and Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
| | - Rachel Upthegrove
- Professor of Psychiatry and Youth Mental Health, University of Birmingham and Consultant Psychiatrist, Birmingham Early Intervention Service, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Angelika Wieck
- Honorary Consultant in Perinatal Psychiatry, Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
| | - Alison R Yung
- Professor of Psychiatry, University of Manchester, School of Health Sciences, Manchester, UK and Centre for Youth Mental Health, University of Melbourne, Australia, and Honorary Consultant Psychiatrist, Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
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55
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Keshavarzi F, Fox T, Whiskey E, Taylor D. Change in plasma concentration of clozapine and norclozapine following a switch of oral formulation. Ther Adv Psychopharmacol 2020; 10:2045125319899263. [PMID: 31976069 PMCID: PMC6958650 DOI: 10.1177/2045125319899263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 12/09/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Clozapine formulation has been shown to affect plasma concentrations of clozapine and norclozapine. Changes in formulation might result in toxicity or treatment failure. METHODS We identified, from electronic records, patients who switched from clozapine tablets to oral liquid or vice versa and compared plasma concentrations before and after the switch. RESULTS We identified 13 patients with 85 blood samples who changed formulation of clozapine. Overall mean standardized clozapine plasma level was 0.67 mg/l daily dose on liquid and 0.87 mg/l daily dose on tablets (p = 0.035). CONCLUSION Use of clozapine liquid results in lower plasma clozapine concentration than the same dose of tablets.
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Affiliation(s)
- Farinaz Keshavarzi
- Pharmacy Department, Maudsley Hospital, South London and Maudsley NHS Foundation Trust, London, UK
| | - Tony Fox
- Institute of Pharmaceutical Science, King's College London, London, UK
| | - Eromona Whiskey
- Pharmacy Department, Maudsley Hospital, South London and Maudsley NHS Foundation Trust, London, UK
| | - David Taylor
- Pharmacy Department, Maudsley Hospital, South London and Maudsley NHS Foundation Trust, Denmark Hill, London, SE5 8AZ, UK
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56
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Costa-Dookhan KA, Agarwal SM, Chintoh A, Tran VN, Stogios N, Ebdrup BH, Sockalingam S, Rajji TK, Remington GJ, Siskind D, Hahn MK. The clozapine to norclozapine ratio: a narrative review of the clinical utility to minimize metabolic risk and enhance clozapine efficacy. Expert Opin Drug Saf 2019; 19:43-57. [PMID: 31770500 DOI: 10.1080/14740338.2020.1698545] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: Clozapine remains the most effective antipsychotic for treatment-refractory schizophrenia. However, ~40% of the patients respond insufficiently to clozapine. Clozapine's effects, both beneficial and adverse, have been proposed to be partially attributable to its main metabolite, N-desmethylclozapine (NDMC). However, the relation of the clozapine to norclozapine ratio (CLZ:NDMC; optimally defined as ~2) to clinical response and metabolic outcomes is not clear.Areas covered: This narrative review comprehensively examines the clinical utility of the CLZ:NDMC ratio to reduce metabolic risk and increase treatment efficacy. The association of the CLZ:NDMC ratio with changes in psychopathology, cognitive functioning, and cardiometabolic burden will be explored, as well as adjunctive treatments and their effects.Expert opinion: The literature suggests a positive association between the CLZ:NDMC ratio and better cardiometabolic outcomes. Conversely, the CLZ:NDMC ratio appears inversely associated with better cognitive functioning but less consistently with other psychiatric domains. The CLZ:NDMC ratio may be useful for predicting and monitoring cardiometabolic adverse effects and optimizing potential cognitive benefits of clozapine. Future studies are required to replicate these findings, which if substantiated, would encourage examination of adjunctive treatments aiming to alter the CLZ:NDMC ratio to best meet the needs of the individual patient, thereby broadening clozapine's clinical utility.
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Affiliation(s)
- Kenya A Costa-Dookhan
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Sri Mahavir Agarwal
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Araba Chintoh
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Veronica N Tran
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Nicolette Stogios
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Bjørn H Ebdrup
- Centre for Neuropsychiatric Schizophrenia Research, CNSR & Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, Mental Health Centre Glostrup, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sanjeev Sockalingam
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Tarek K Rajji
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Gary J Remington
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Dan Siskind
- School of Medicine, University of Queensland, Brisbane, Australia.,Schizophrenia Department, Metro South Addiction and Mental Health Service, Brisbane, Australia
| | - Margaret K Hahn
- Schizophrenia Department, Centre for Addiction and Mental Health, Toronto, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada.,Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
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57
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Lesche D, Mostafa S, Everall I, Pantelis C, Bousman CA. Impact of CYP1A2, CYP2C19, and CYP2D6 genotype- and phenoconversion-predicted enzyme activity on clozapine exposure and symptom severity. THE PHARMACOGENOMICS JOURNAL 2019; 20:192-201. [PMID: 31616047 DOI: 10.1038/s41397-019-0108-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 12/14/2022]
Abstract
Clozapine is an atypical antipsychotic metabolized by CYP1A2, CYP2D6, and CYP2C19 enzymes. Among 66 adult schizophrenia patients treated with clozapine-based combination therapies, we explored the impact of genotype-predicted CYP1A2, CYP2D6, and CYP2C19 activity on dose-adjusted clozapine concentrations and symptom severity, with and without correction for inhibitors and inducers of these enzymes. Uncorrected activity scores were not associated with dose-adjusted clozapine concentrations or symptom severity. CYP1A2 and CYP2D6 activity scores corrected for known inducers (i.e., smoking) and inhibitors (e.g., concomitant medications) were associated with dose-adjusted clozapine levels and in the case of CYP1A2, symptom severity. However, smoking status and certain inhibitors of clozapine metabolism (i.e., esomeprazole) explained significantly more variance in dose-adjusted clozapine levels relative to corrected activity scores. These findings highlight the clinical importance of nongenetic factors (smoking, concomitant medications) and suggest that the added utility of CYP1A2, CYP2D6, and CYP2C19 activity scores to guide clozapine dosing is currently limited.
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Affiliation(s)
- Dorothea Lesche
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne & Melbourne Health, Melbourne, VIC, Australia
| | - Sam Mostafa
- myDNA Life Australia Limited, South Yarra, VIC, Australia.,Centre for Medicine Use and Safety, Monash University, Parkville, VIC, Australia
| | - Ian Everall
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne & Melbourne Health, Melbourne, VIC, Australia.,Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia.,The Cooperative Research Centre (CRC) for Mental Health, VIC, Australia
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne & Melbourne Health, Melbourne, VIC, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia.,The Cooperative Research Centre (CRC) for Mental Health, VIC, Australia
| | - Chad A Bousman
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne & Melbourne Health, Melbourne, VIC, Australia. .,The Cooperative Research Centre (CRC) for Mental Health, VIC, Australia. .,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Departments of Medical Genetics, Psychiatry, and Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.
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58
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Sangüesa E, Cirujeda C, Concha J, Padilla PP, Ribate MP, García CB. Implementation of pharmacogenetics in a clozapine treatment resistant patient: a case report. Pharmacogenomics 2019; 20:871-877. [DOI: 10.2217/pgs-2019-0074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We report the case of a young Caucasian male with disorganized chronic schizophrenia, an active smoker and nonresponder to 400 mg of clozapine/day. Therapeutic clozapine monitoring was analyzed revealing a low clozapine:norclozapine ratio. An additional pharmacogenetic test was carried out showing that the patient carried *1F variant ( CYP1A2 gene), which has been associated with nonresponse to clozapine in smoker patients. A genetic variation in the SLC6A4 gene was also found, which could be related to the poor response to clozapine. The remainder of the genes analyzed ( CYP2D6, ABCB1 and HTR2A) were not directly associated with the patient’s phenotype. The dose of clozapine was increased to 600 mg/day, reaching the therapeutic range. This case shows how pharmacogenetics can help in understanding the value of plasma levels to provide clinical improvement.
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Affiliation(s)
- Estela Sangüesa
- Pharmacy Degree, Faculty of Health Sciences, Universidad San Jorge, Villanueva de Gállego- Zaragoza, Spain
| | - Christine Cirujeda
- Centro Neuropsiquiátrico Nuestra Señora del Carmen. Hermanas Hospitalarias, Zaragoza, Spain
| | - Julia Concha
- Pharmacy Degree, Faculty of Health Sciences, Universidad San Jorge, Villanueva de Gállego- Zaragoza, Spain
| | - Pedro Pablo Padilla
- Centro Neuropsiquiátrico Nuestra Señora del Carmen. Hermanas Hospitalarias, Zaragoza, Spain
| | - María Pilar Ribate
- Pharmacy Degree, Faculty of Health Sciences, Universidad San Jorge, Villanueva de Gállego- Zaragoza, Spain
| | - Cristina Belén García
- Pharmacy Degree, Faculty of Health Sciences, Universidad San Jorge, Villanueva de Gállego- Zaragoza, Spain
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59
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Schoretsanitis G, Kane JM, Ruan CJ, Spina E, Hiemke C, de Leon J. A comprehensive review of the clinical utility of and a combined analysis of the clozapine/norclozapine ratio in therapeutic drug monitoring for adult patients. Expert Rev Clin Pharmacol 2019; 12:603-621. [DOI: 10.1080/17512433.2019.1617695] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Georgios Schoretsanitis
- Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, NY, USA
- Hofstra Northwell School of Medicine, Hempstead, NY, USA
- Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - John M. Kane
- Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, NY, USA
- Hofstra Northwell School of Medicine, Hempstead, NY, USA
- Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Can-Jun Ruan
- Laboratory of Clinical Psychopharmacology & The National Clinical Research Centre for Mental Disorders & Beijing Key Lab of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Edoardo Spina
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Christoph Hiemke
- Department of Psychiatry and Psychotherapy, University Medical Center of Mainz, Mainz, Germany
| | - Jose de Leon
- University of Kentucky Mental Health Research Center at Eastern State Hospital, Lexington, KY, USA
- Psychiatry and Neurosciences Research Group (CTS-549), Institute of Neurosciences, University of Granada, Granada, Spain
- Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apostol Hospital, University of the Basque Country, Vitoria, Spain
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60
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Olmos I, Ibarra M, Vázquez M, Maldonado C, Fagiolino P, Giachetto G. Population Pharmacokinetics of Clozapine and Norclozapine and Switchability Assessment between Brands in Uruguayan Patients with Schizophrenia. BIOMED RESEARCH INTERNATIONAL 2019; 2019:3163502. [PMID: 30956977 PMCID: PMC6431368 DOI: 10.1155/2019/3163502] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/14/2019] [Indexed: 01/01/2023]
Abstract
Clozapine (CZP) is an atypical antipsychotic agent commonly used in the treatment of schizophrenia. It is metabolized primarily by CYP1A2 enzyme, yielding a pharmacologically active metabolite, norclozapine (NCZP). Significant intra- and interindividual pharmacokinetic (PK) variability for CZP and NCZP has been observed in routine therapeutic drug monitoring. So the goal of this study was to evaluate the magnitude and variability of concentration exposure to CZP and its active metabolite NCZP on pharmacokinetic parameters in Uruguayan patients with schizophrenia with a focus on covariates such as cigarette smoking, age, sex, caffeine consumption, brands available of CZP, and comedication using population PK (PPK) modeling methodologies. Patients with a diagnosis of schizophrenia treated with brand-name CZP (Leponex®) for more than a year were included in the study. Then these patients were switched to the similar brand of CZP (Luverina®). Morning predose blood samples for determination of CZP and NCZP using a HPLC system equipped with a UV detector were withdrawn on both occasions at steady state and under the same comedication. Ninety-eight patients, 22 women and 76 men, took part in the study. Mean ± standard deviation for CZP and NCZP concentration was 421 ± 262 ng/mL and 275 ± 180 ng/mL, respectively. After covariate evaluation, only smoking status remained significant in CZP apparent clearance, inducing a mean increment of 32% but with no clinical impact. The results obtained with the two brands of CZP should ensure comparable efficacy and tolerability with the clinical use of either product. Smoking was significantly associated with a lower exposure to CZP due to higher clearance. The results obtained with the two brands commercialized in our country hint a bioequivalence scenario in the clinical setting.
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Affiliation(s)
- Ismael Olmos
- Pharmacy Department, Vilardebó Hospital, Avenida Millán 2515, 11800 Montevideo, Uruguay
| | - Manuel Ibarra
- Pharmaceutical Sciences Department, Faculty of Chemistry, Universidad de la República, Avenida General Flores 2124, P. O. Box 1157, 11800 Montevideo, Uruguay
| | - Marta Vázquez
- Pharmaceutical Sciences Department, Faculty of Chemistry, Universidad de la República, Avenida General Flores 2124, P. O. Box 1157, 11800 Montevideo, Uruguay
| | - Cecilia Maldonado
- Pharmaceutical Sciences Department, Faculty of Chemistry, Universidad de la República, Avenida General Flores 2124, P. O. Box 1157, 11800 Montevideo, Uruguay
| | - Pietro Fagiolino
- Pharmaceutical Sciences Department, Faculty of Chemistry, Universidad de la República, Avenida General Flores 2124, P. O. Box 1157, 11800 Montevideo, Uruguay
| | - Gustavo Giachetto
- C Pediatrics Clinics, Pereira Rossell Hospital, Bulevar Gral. Artigas 1550, 11600 Montevideo, Faculty of Medicine, Universidad de la República, Uruguay
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Fernandez-Egea E, Worbe Y, Bernardo M, Robbins TW. Distinct risk factors for obsessive and compulsive symptoms in chronic schizophrenia. Psychol Med 2018; 48:2668-2675. [PMID: 29455687 PMCID: PMC6236440 DOI: 10.1017/s003329171800017x] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 12/17/2017] [Accepted: 01/11/2018] [Indexed: 01/28/2023]
Abstract
BACKGROUND Obsessive-compulsive disorder (OCD) is common in clozapine-treated patients although the actual prevalence, phenomenology and risk factors remain unclear. The aim of the present study was to address the three aforementioned questions. METHODS The electronic records of a large cohort of clozapine-medicated schizophrenia patients routinely screened for OCD were used. The Obsessive Compulsive Inventory Revised version (OCI-R) was available from 118 cases and a 21 points cut-off threshold for OCD was defined. RESULTS OCD prevalence was 47%, higher in patients on poly-pharmacy than on monotherapy (64% vs 31%; p = 0.001). Two OCI-R factors had significantly higher scores and distinct risk factors: checking behaviour (mean = 5.1; SD = 3.6) correlated with length of clozapine treatment (r = 0.21; p = 0.026), and obsessing factor (mean = 4.8; SD = 3.6) correlated with psychosis severity (r = 0.59; p = 0.001). These factors along with total OCI-R, did not correlate with either clozapine dose or plasma levels, after correcting for psychosis severity. CONCLUSIONS Screening for OCD in clozapine patients, and probably in those treated with structurally similar drugs with potent antiserotoninergic properties, should be widely adopted by clinicians. Further research is needed to understand the pathophysiology underlying repetitive behavior onset in clozapine-treated patients.
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Affiliation(s)
- Emilio Fernandez-Egea
- Clozapine Clinic, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Yulia Worbe
- Sorbonne Université, 75005 Paris, France; Department of Physiology, Neurophysiology Unit, Hospital Saint-Antoine, Paris, France; Institute du Cerveau et de Moelle Epigniere, Paris, France
| | - Miguel Bernardo
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
- Barcelona Clinic Schizophrenia Unit, Neuroscience Institute, Hospital Clinic of Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Department of Psychiatry, University of Barcelona, Barcelona, Spain
| | - Trevor W. Robbins
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Psychology, University of Cambridge, Cambridge, UK
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Reznik R, Chen RYY, Stanford P. Clozapine toxicity in a CYP2D6 poor metaboliser: Additive effects of haloperidol and valproate on clozapine metabolism. Australas Psychiatry 2018; 26:608-611. [PMID: 29737183 DOI: 10.1177/1039856218771509] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE: To illustrate the complexities of clozapine metabolism with the use of therapeutic drug monitoring. METHODS: We describe a case of clozapine toxicity in a patient with schizophrenia treated with the combination of clozapine, valproate and haloperidol. RESULTS: A 24-year-old CYP2D6 poor metaboliser developed clozapine toxicity corresponding to the additive effects of haloperidol, and increasing clozapine and valproate doses. Saturation of metabolism, evidenced by a high clozapine/norclozapine ratio, was present at this time. CONCLUSIONS: Clozapine metabolism is complex and influenced by multiple factors, including interactions with hepatic P450 enzyme inducers/inhibitors, genetic polymorphisms and the potential for saturation of the N-demethylation metabolic pathway.
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Affiliation(s)
- Robert Reznik
- VMO Consultant Psychiatrist, Long Bay Hospital, Matraville, NSW, Australia
| | | | - Phoebe Stanford
- Clinical Chemistry Registrar, NSW Health Pathology, The Prince of Wales Hospital, Randwick, NSW, Australia
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The Effect of Body Weight Changes on Total Plasma Clozapine Concentrations Determined by Applying a Statistical Model to the Data From a Double-Blind Trial. J Clin Psychopharmacol 2018; 38:442-446. [PMID: 30106876 PMCID: PMC6113094 DOI: 10.1097/jcp.0000000000000926] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE/BACKGROUND Some therapeutic drug monitoring studies suggest that increased weight is associated with small increases in clozapine concentrations. The goal of this study was to reanalyze a US double-blind study using a sophisticated statistical model to test whether weight gains from baseline or increases in percentage of body fat from baseline, computed from a published equation, are associated with increased total plasma clozapine concentrations after controlling for the effects of smoking and sex. METHODS/PROCEDURES Using data from a multidosage randomized double-blind US clozapine trial previously published, a random intercept linear model of steady-state total plasma clozapine concentrations was fitted to 424 concentrations from 47 patients. FINDINGS/RESULTS After adjusting for sex and smoking, (1) a 1-kg gain in body weight during clozapine treatment was significantly associated with a 1.4% increase in total plasma clozapine concentrations (95% confidence interval = 0.55 to 2.3) and (2) a 1-point increase in percentage of body fat during clozapine treatment was significantly associated with a 5.4% increase in total clozapine concentration (2.5 to 8.3) in females and 1.4% (-1.1 to 4.0) in males. IMPLICATIONS/CONCLUSIONS As hypothesized, weight increases during clozapine treatment, which probably reflect increases in fat tissue, were associated with increases in total plasma concentrations. Pending further replication in other samples, it seems likely that clozapine may deposit in body fat and that this may decrease clozapine clearance. This change may be small in most patients but may be clinically relevant in females with major gains in body fat.
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Effect of Valproate and Antidepressant Drugs on Clozapine Metabolism in Patients With Psychotic Mood Disorders. Ther Drug Monit 2018; 40:443-451. [DOI: 10.1097/ftd.0000000000000513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
OBJECTIVES Valproic acid and clozapine are drugs commonly used in the treatment of schizophrenic and schizoaffective disorders. Pharmacokinetic interactions of valproic acid with several drugs are well known, yet results concerning the interaction with clozapine are inconsistent. METHODS Steady-state dose-corrected serum concentrations of clozapine and its main metabolite norclozapine were retrospectively analyzed in 45 patients receiving both clozapine and valproic acid. Controls were matched for sex, age, smoking, comedication, and inflammatory response. RESULTS The group receiving comedication with valproic acid showed significantly lower median dose-corrected serum concentrations of norclozapine (0.44 [0.27-0.58] (ng/mL)/(mg/d) vs 0.78 [0.60-1.07] (ng/mL)/(mg/d)) as well as metabolite to parent compound ratios (0.40 [0.36-0.47] vs 0.71 [0.58-0.84]) by approximately 44%. Dose-corrected serum concentrations of clozapine were not significantly lower. The effect of valproic acid was independent of sex and smoking. CONCLUSIONS Comedication with valproic acid accelerated metabolism of clozapine with predominant effects on the degradation of norclozapine. Therapeutic drug monitoring should be applied to guide individual patient responses upon initiation of comedication.
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Mogwitz S, Buse J, Wolff N, Roessner V. Update on the Pharmacological Treatment of Tics with Dopamine-Modulating Agents. ACS Chem Neurosci 2018; 9:651-672. [PMID: 29498507 DOI: 10.1021/acschemneuro.7b00460] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
More than 40 years of research and clinical practice have proven the effectiveness of dopamine receptor antagonists in the pharmacological treatment of tics. A blockade of the striatal dopamine-D2 receptors is mainly responsible for their tic-reducing effect. A broad spectrum of dopamine-modulating agents, such as typical and atypical antipsychotics, but also dopamine receptor agonists are used with an immanent discord between experts about which of them should be considered as first choice. The present Review outlines the state of the art on pharmacological treatment of tics with dopamine-modulating agents by giving an systematic overview of studies on their effectiveness and a critical discussion of their specific adverse effects. It is considered as an update of a previous review of our research group published in 2013. The Review closes with a description of the current resulting treatment recommendations including the results of a first published revised survey on European expert's prescription preferences. Based on the enormously growing evidence on its effectiveness and safety, aripiprazole currently seems to be the most promising agent in the pharmacological treatment of tics. Furthermore, benzamides (especially tiapride), which are commonly used in Europe, have proven their excellent effectiveness-tolerability profile over decades in clinical practice and are therefore also highly recommended for the treatment of tics. Nevertheless, pharmacological treatment of tics remains an indiviual choice depending on each patient's own specific needs.
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Affiliation(s)
- Sabine Mogwitz
- Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany
| | - Judith Buse
- Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany
| | - Nicole Wolff
- Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany
| | - Veit Roessner
- Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany
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Clark SR, Warren NS, Kim G, Jankowiak D, Schubert KO, Kisely S, Forrester T, Baune BT, Siskind DJ. Elevated clozapine levels associated with infection: A systematic review. Schizophr Res 2018; 192:50-56. [PMID: 28392207 DOI: 10.1016/j.schres.2017.03.045] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/27/2017] [Accepted: 03/29/2017] [Indexed: 11/27/2022]
Abstract
Clozapine is the most effective anti-psychotic medication for treatment refractory schizophrenia. A growing number of case reports have linked infection to high clozapine levels and associated adverse outcomes. We present a systematic review of published cases to clarify the relationship between infection and elevated clozapine levels. The case reports were located through PubMed and Embase. In addition, 8 new cases from two Australian states were included. Demographics, psychiatric diagnoses and medical morbidities, medications, clinical symptoms, clozapine levels, inflammatory markers and final clinical outcome were extracted. 40 cases were identified in 23 publications that demonstrated elevated clozapine levels associated with infection. Infections were commonly respiratory in origin. Adverse events, typically sedation, were associated with raised clozapine levels during infection. In many cases the signs of infection such as fever and white blood cell count were reduced. Severe adverse effects were uncommon, with one case each of seizure, myocarditis and neutropenia. The relationship between infection, clozapine levels and adverse events is complex and multi-factorial. Monitoring of clozapine levels is essential during hospitalisation for infection and consideration should be given to gradual dose reduction to minimise dose related side effects.
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Affiliation(s)
- Scott R Clark
- University of Adelaide, Department of Psychiatry, Adelaide, SA 5005, Australia
| | - Nicola S Warren
- Metro South Addiction and Mental Health Service, Brisbane, QLD 4012, Australia; University of Queensland, School of Medicine, Brisbane, QLD 4072, Australia.
| | - Gajin Kim
- University of Adelaide, Department of Psychiatry, Adelaide, SA 5005, Australia
| | - David Jankowiak
- Southern Adelaide Local Health Network, Adelaide, South Australia 5042, Australia
| | - Klaus Oliver Schubert
- University of Adelaide, Department of Psychiatry, Adelaide, SA 5005, Australia; Northern Adelaide Local Health Network, Adelaide, South Australia 5112, Australia
| | - Steve Kisely
- Metro South Addiction and Mental Health Service, Brisbane, QLD 4012, Australia; University of Queensland, School of Medicine, Brisbane, QLD 4072, Australia
| | - Tori Forrester
- Princess Alexandra Hospital, Brisbane, QLD 4012, Australia
| | - Bernhard T Baune
- University of Adelaide, Department of Psychiatry, Adelaide, SA 5005, Australia
| | - Dan J Siskind
- Metro South Addiction and Mental Health Service, Brisbane, QLD 4012, Australia; University of Queensland, School of Medicine, Brisbane, QLD 4072, Australia
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68
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Clozapine and Norclozapine Concentrations in Paired Human Plasma and Serum Samples. Ther Drug Monit 2018; 40:148-150. [DOI: 10.1097/ftd.0000000000000478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Mayerova M, Ustohal L, Jarkovsky J, Pivnicka J, Kasparek T, Ceskova E. Influence of dose, gender, and cigarette smoking on clozapine plasma concentrations. Neuropsychiatr Dis Treat 2018; 14:1535-1543. [PMID: 29950838 PMCID: PMC6011879 DOI: 10.2147/ndt.s163839] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Therapeutic drug monitoring (TDM) of clozapine is a very useful method for verifying both the correct intake and the interindividual variability of its metabolism, thereby avoiding the risk of toxicity. The purposes of this paper were to discover how many patients using clozapine in common clinical practice have clozapine plasma concentration (PC) levels in the proposed reference range and to identify factors that influence clozapine PC levels. METHODS Our study included 100 inpatients (diagnosed with schizophrenia or schizoaffective disorder) taking standard doses of clozapine (100-700 mg/day). Clozapine concentration was measured by high-performance liquid chromatography. Correlations between doses and PC levels and the influence of smoking and gender on clozapine PC levels were calculated. RESULTS A large number of the patients (67%) had PC levels outside the proposed reference range. The clozapine PC levels were influenced by dose, gender, and cigarette smoking. CONCLUSION The correlations between dose, gender, and cigarette smoking and clozapine PC levels highlighted by our study overlap other research. It was surprising to find such a large number of patients with clozapine PC levels outside the therapeutic range. This result suggests the importance of clozapine TDM due to misunderstood inter- and/or intraindividual variability or misestimated partial therapeutic compliance.
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Affiliation(s)
- Michaela Mayerova
- Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Department of Psychiatry, University Hospital Brno, Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Libor Ustohal
- Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Department of Psychiatry, University Hospital Brno, Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Jiri Jarkovsky
- Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic
| | - Jan Pivnicka
- Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Institute of Forensic Medicine, St. Anne's University Hospital, Masaryk University, Brno, Czech Republic
| | - Tomas Kasparek
- Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Department of Psychiatry, University Hospital Brno, Brno, Czech Republic
| | - Eva Ceskova
- Faculty of Medicine, Masaryk University, Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
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Comparison of Population Pharmacokinetics Based on Steady-State Assumption Versus Electronically Monitored Adherence to Lopinavir, Atazanavir, Efavirenz, and Etravirine: A Retrospective Study. Ther Drug Monit 2017; 38:506-15. [PMID: 26937748 DOI: 10.1097/ftd.0000000000000297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Population pharmacokinetic (PopPK) analyses often rely on steady state and full adherence to prescribed dosage regimen assumptions from data gathered during therapeutic drug monitoring (TDM). Nonadherence is common in chronic diseases such as HIV. This study evaluates the impact of adherence measurement by electronic monitoring on PopPK parameter estimation and individual concentration profile predictions, and also the influence of adherence issues on the clinical interpretation of a concentration measurement. METHODS Published PopPK models for lopinavir, atazanavir, efavirenz, and etravirine were applied to estimate PK parameters and individual concentrations in 140 HIV patients taking part in a medication adherence program using 2 dosing data sets. The first set included the last dose reported by the patient with steady-state and full adherence assumptions; the second set used detailed electronic dosing history. PopPK parameter estimates and individual predictions were compared between the 2 dosing entries. RESULTS Clearance estimates and likewise predicted concentrations did not markedly differ between the 2 dosing histories. However, certain patterns of nonadherence such as sparse missed doses or consecutive missed doses lead to suboptimal drug exposure. The interpretation based on self-reported information would have concluded on a wrongly appropriate individual exposure. CONCLUSIONS PopPK analysis assuming steady state with full adherence produced similar results to those based on detailed electronic dosing history reconciled with patients' allegations. Self-reported last dose intake appeared reliable for concentration predictions and therapeutic drug monitoring interpretation for most patients followed at the medication adherence program. Yet, clinicians should be aware that concentration predictions based on self-reported last dose intake might be overestimated in case of undetected patterns of nonadherence, increasing the risk of forthcoming therapeutic failure.
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Concentrations in plasma clozapine levels in schizophrenic and schizoaffective patients. REVISTA DE PSIQUIATRIA Y SALUD MENTAL 2017; 10:192-196. [PMID: 28844295 DOI: 10.1016/j.rpsm.2017.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 12/19/2022]
Abstract
INTRODUCTION There is great variability in plasma levels of clozapine. The objective of this study is to know the characteristics of patients treated with clozapine and the relationship between them and the variability of plasma levels. MATERIAL AND METHODS Descriptive, cross-sectional study of all patients currently treated with clozapine in a Psychiatric Service with a diagnosis of schizophrenic psychosis or schizoaffective disorder. The present study assessed physical situation, psychopathology and functionality of the patients and explored the associations and correlations between clinical variables and plasma levels. RESULTS We studied 39 patients, predominantly men, with negative and depressive symptoms and cardiovascular risk factors (metabolic syndrome and smoking). Significant variability in dose and even greater in clozapine levels were observed. The levels of clozapine at equal doses/kg of body weight were higher in non-smokers, they had positive correlation with BMI and negative correlation with systolic BP, disruptive behaviors and number of cigarettes consumed. CONCLUSION Plasma level monitoring clozapine is an important tool to avoid clozapine plasma levels monitoring and minimize undesirable clinical situations (metabolic syndrome, sedation, negative symptoms and functional impairment). It is also important to control the effects of a smoking habit for optimum drug bioavailability.
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Couchman L, Fisher DS, Subramaniam K, Handley SA, Boughtflower RJ, Benton CM, Flanagan RJ. Ultra-fast LC-MS/MS in therapeutic drug monitoring: Quantification of clozapine and norclozapine in human plasma. Drug Test Anal 2017; 10:323-329. [PMID: 28585411 DOI: 10.1002/dta.2223] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 11/09/2022]
Abstract
A novel approach to high-throughput, targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has been developed. A single chromatographic system can be used for the analysis of a range of 20 drugs and metabolites with a total analysis time of 36 s (one 96-well plate of prepared samples per hour). To demonstrate the applicability of this approach to quantitative analysis, a method has been validated for the therapeutic drug monitoring of clozapine and norclozapine following automated extraction from human plasma. Chromatographic retention times were 11.4 and 12.4 s for norclozapine and clozapine, respectively (for both analytes the chromatographic peak width was less than 1 s). Comparison with a conventional LC-MS/MS method (5 min analysis time) showed excellent agreement. This new approach offers analysis times more akin to flow-injection analysis, but is likely to be more widely applicable because of chromatographic resolution from residual matrix components and isobaric interferences.
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Affiliation(s)
- Lewis Couchman
- Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK.,Pharmaceutical Sciences Clinical Academic Group, King's College London, London, UK
| | - Danielle S Fisher
- Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
| | - Krithika Subramaniam
- Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
| | - Simon A Handley
- Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
| | | | | | - Robert J Flanagan
- Viapath Analytics, Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK.,Pharmaceutical Sciences Clinical Academic Group, King's College London, London, UK
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Every-Palmer S, Lentle RG, Reynolds G, Hulls C, Chambers P, Dunn H, Ellis PM. Spatiotemporal Mapping Techniques Show Clozapine Impairs Neurogenic and Myogenic Patterns of Activity in the Colon of the Rabbit in a Dose-Dependent Manner. Front Pharmacol 2017; 8:209. [PMID: 28484390 PMCID: PMC5401895 DOI: 10.3389/fphar.2017.00209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 04/05/2017] [Indexed: 01/03/2023] Open
Abstract
Background: Clozapine, an antipsychotic used in treatment-resistant schizophrenia, has adverse gastrointestinal effects with significant associated morbidity and mortality. However, its effects on defined patterns of colonic contractile activity have not been assessed. Method: We used novel radial and longitudinal spatiotemporal mapping techniques, combined with and monitoring of ambient lumen pressure, in ex vivo preparations of triply and of singly haustrated portions of rabbit colon. We identified the contractile patterns of mass peristalses, fast phasic, and ripple contractions and directly qualified the effects of clozapine, at concentrations of 10 μmol/L, 20 μmol/L, and 30 μmol/L, and of norclozapine, the main metabolite of clozapine, on contractile patterns. The effects of carbachol, serotonin and naloxone on clozapine-exposed preparations were also determined. Tetradotoxin was used to distinguish neurogenic from myogenic contractions. Results: At 10 μmol/L, clozapine temporarily abolished the longitudinal contractile components of mass peristalsis, which on return were significantly reduced in number and amplitude, as was maximal mass peristaltic pressure. These effects were reversed by carbachol (1 μmol/L) and to some extent by serotonin (15 μmol/L). At 10 μmol/L, myogenic ripple contractions were not affected. At 20 μmol/L, clozapine had a similar but more marked effect on mass peristalses with both longitudinal and radial components and corresponding maximal pressure greatly reduced. At 30 μmol/L, clozapine suppressed the radial and longitudinal components of mass peristalses for over 30 min, as well as ripple contractions. Similar dose-related effects were observed on addition of clozapine to the mid colon. At 20 μmol/L, norclozapine had opposite effects to those of clozapine, causing an increase in the frequency of mass peristalsis with slight increases in basal tone. These slightly augmented contractions were abolished on addition of clozapine. Concentrations of norclozapine below 20 μmol/L had no discernible effects. Conclusion: Clozapine, but not norclozapine, has potent effects on the motility of the rabbit colon, inhibiting neurogenic contractions at lower concentrations and myogenic contractions at higher concentrations. This is the likely mechanism for the serious and life-threatening gastrointestinal complications seen in human clozapine-users. These effects appear to be mediated by cholinergic and serotonergic mechanisms. Spatiotemporal mapping is useful in directly assessing the effects of pharmaceuticals on particular patterns of gastrointestinal motility.
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Affiliation(s)
- Susanna Every-Palmer
- Te Korowai Whāriki Central Regional Forensic Service, Capital and Coast District Health BoardWellington, New Zealand.,Department of Psychological Medicine, University of OtagoWellington, New Zealand
| | - Roger G Lentle
- Institute of Food, Nutrition and Human Health, Massey UniversityPalmerston North, New Zealand
| | - Gordon Reynolds
- Institute of Food, Nutrition and Human Health, Massey UniversityPalmerston North, New Zealand
| | - Corrin Hulls
- Institute of Food, Nutrition and Human Health, Massey UniversityPalmerston North, New Zealand
| | - Paul Chambers
- Institute of Veterinary, Animal and Biomedical Sciences, Massey UniversityPalmerston North, New Zealand
| | - Helen Dunn
- Pharmacy Department, Capital and Coast District Health BoardWellington South, New Zealand
| | - Pete M Ellis
- Department of Psychological Medicine, University of OtagoWellington, New Zealand
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Measurement of Clozapine, Norclozapine, and Amisulpride in Plasma and in Oral Fluid Obtained Using 2 Different Sampling Systems. Ther Drug Monit 2017; 39:109-117. [DOI: 10.1097/ftd.0000000000000377] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tóth K, Csukly G, Sirok D, Belic A, Kiss Á, Háfra E, Déri M, Menus Á, Bitter I, Monostory K. Potential Role of Patients' CYP3A-Status in Clozapine Pharmacokinetics. Int J Neuropsychopharmacol 2017; 20:529-537. [PMID: 28340122 PMCID: PMC5492788 DOI: 10.1093/ijnp/pyx019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/17/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The atypical antipsychotic clozapine is effective in treatment-resistant schizophrenia; however, the success or failure of clozapine therapy is substantially affected by the variables that impact the clozapine blood concentration. Thus, elucidating the inter-individual differences in clozapine pharmacokinetics can facilitate the personalized therapy. METHODS Since a potential role in clozapine metabolism is assigned to CYP1A2, CYP2C19, CYP2D6 and CYP3A enzymes, the association between the patients' CYP status (CYP genotypes, CYP expression) and clozapine clearance was evaluated in 92 psychiatric patients. RESULTS The patients' CYP2C19 or CYP2D6 genotypes and CYP1A2 expression seemed to have no effect on clozapine serum concentration, whereas CYP3A4 expression significantly influenced the normalized clozapine concentration (185.53±56.53 in low expressers vs 78.05±29.57 or 66.52±0.25 (ng/mL)/(mg/kg) in normal or high expressers, P<.0001), in particular that the patients expressed CYP1A2 at a relatively low level. The functional CYP3A5*1 allele seemed to influence clozapine concentrations in those patients who expressed CYP3A4 at low levels. The dose requirement for the therapeutic concentration of clozapine was substantially lower in low CYP3A4 expresser patients than in normal/high expressers (2.18±0.64 vs 4.98±1.40 mg/kg, P<.0001). Furthermore, significantly higher plasma concentration ratios of norclozapine/clozapine and clozapine N-oxide/clozapine were observed in the patients displaying normal/high CYP3A4 expression than in the low expressers. CONCLUSION Prospective assaying of CYP3A-status (CYP3A4 expression, CYP3A5 genotype) may better identify the patients with higher risk of inefficiency or adverse reactions and may facilitate the improvement of personalized clozapine therapy; however, further clinical studies are required to prove the benefit of CYP3A testing for patients under clozapine therapy.
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Affiliation(s)
- Katalin Tóth
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Gábor Csukly
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Dávid Sirok
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Ales Belic
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Ádám Kiss
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Edit Háfra
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Máté Déri
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Ádám Menus
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - István Bitter
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
| | - Katalin Monostory
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest Hungary (Ms Tóth, Mr Sirok, Mr Kiss, Ms Háfra, Mr Déri, and Dr Monostory); Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest Hungary (Drs Csukly, Menus, and Bitter); Toxi-Coop Toxicological Research Center, Budapest Hungary (Mr Sirok); University of Ljubljana, Ljubljana Slovenia (Dr Belic)
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Kolli V, Bourke D, Ngo J, Luber MJ, Coffey BJ. Clozapine-Related Tachycardia in an Adolescent with Treatment-Resistant Early Onset Schizophrenia. J Child Adolesc Psychopharmacol 2017; 27:206-208. [PMID: 28323458 DOI: 10.1089/cap.2017.29123.bjc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Venkata Kolli
- 1 Department of Psychiatry, Creighton University , Omaha, Nebraska
| | - Dalton Bourke
- 1 Department of Psychiatry, Creighton University , Omaha, Nebraska
| | - Jeannie Ngo
- 1 Department of Psychiatry, Creighton University , Omaha, Nebraska
| | - Maxwell J Luber
- 2 Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, New York
| | - Barbara J Coffey
- 2 Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, New York
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77
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Yousra H, Pierrick L, Laurent L, Danièle D. Interaction between clozapine and oxcarbazepine: a case report. Ther Adv Psychopharmacol 2017; 7:95-99. [PMID: 28255440 PMCID: PMC5315233 DOI: 10.1177/2045125316681472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Hazel Yousra
- Department of Psychiatry, Esquirol Center, University Hospital of Caen, Caen, France
| | | | - Lecardeur Laurent
- Department of Psychiatry, Esquirol Center, University Hospital of Caen, Caen, France
| | - Debruyne Danièle
- Department of Pharmacology and Toxicology, University Hospital of Caen, Caen, France
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Vasudev K, Choi YH, Norman R, Kim RB, Schwarz UI. Genetic Determinants of Clozapine-Induced Metabolic Side Effects. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2017; 62:138-149. [PMID: 27681143 PMCID: PMC5298525 DOI: 10.1177/0706743716670128] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Atypical antipychotics are linked to a higher incidence of metabolic side effects, including weight gain, dyslipidemia, and diabetes. In this study, we examined the prevalence and potential genetic predictors of metabolic side effects in 60 adult patients on clozapine. METHOD Genetic variants of relevance to clozapine metabolism, clearance, and response were assessed through targeted genotyping of cytochrome P450 enzymes CYP1A2 and CYP2C19, the efflux transporter ABCB1, the serotonin receptor (HTR2C), leptin (LEP), and leptin receptor (LEPR). Clozapine levels and other potential confounders, including concurrent medications, were also included in the analysis. RESULTS More than half of the patients were obese (51%), had metabolic syndrome (52.5%), and 30.5% were overweight. There was a high prevalence of antipsychotic polypharmacy (61.9%). With multivariable linear regression analysis, LEP -2548G>A, LEPR c.668A>G, and HTR2C c.551-3008 C>G were identified as genetic predictors of body mass index (BMI) after considering effects of clozapine dose, blood level, and concurrent medications (adjusted R2 = 0.305). Metabolic syndrome was found to be significantly associated with clozapine level and CYP2C19*2 and LEPR c.668 G alleles. Clozapine levels in patients with metabolic syndrome were significantly higher compared to those without metabolic syndrome (1886 ± 895 vs. 1283 ± 985 ng/mL, P < 0.01) and were associated with the CYP2C19*2 genotype. No association was found between the genetic variants studied and lipid or glucose levels. CONCLUSION This study confirms a high prevalence of metabolic side effects with clozapine and suggests higher clozapine level and pharmacogenetic markers in CYP2C19, LEP, LEPR, and HTR2C receptors as important predictors of BMI and metabolic syndrome.
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Affiliation(s)
- Kamini Vasudev
- 1 Departments of Psychiatry and Medicine, Western University, London, Ontario
| | - Yun-Hee Choi
- 2 Department of Epidemiology and Biostatistics, Western University, London, Ontario
| | - Ross Norman
- 3 Department of Psychiatry and Epidemiology and Biostatistics, Western University, London, Ontario
| | - Richard B Kim
- 4 Department of Medicine, Physiology & Pharmacology, and Oncology, Western University, London, Ontario
| | - Ute I Schwarz
- 4 Department of Medicine, Physiology & Pharmacology, and Oncology, Western University, London, Ontario
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79
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Tomko JR, Ahmed N, Kuntz C, Zick J. A Reasonable Alternative to Clozapine in the Chronically Relapsing Smoking Patient? A Retrospective Analysis. Hosp Pharm 2016; 51:834-840. [PMID: 27928189 DOI: 10.1310/hpj5110-834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background: Clozapine levels are severely decreased by cigarette smoke hydrocarbons. A new agent that is unaffected by smoking is paliperidone palmitate. Objective: The purpose of this study is to retrospectively evaluate hospital readmission and time until readmission for patients prescribed paliperidone palmitate intramuscular injection (PP) as an alternative to oral clozapine for patients with severe schizophrenia who resume smoking following discharge. A secondary analysis was performed to determine whether smoking status alone affects hospital readmission rates in both smoking and nonsmoking clozapine-treated patients. Methods: This was a retrospective analysis of all patients who were positive for smoking at admission and readmission who were prescribed clozapine and PP. Smokers were identified by concurrent orders for nicotine replacement. Readmission rates and time until readmission were determined. Data were analyzed utilizing nonparametric statistical methods. Results: A total of 133 subjects were identified, including 108 smokers in PP group, 18 smokers in clozapine group, and 7 nonsmoking clozapine patients. Readmission rates were statistically significant between smokers in the clozapine and PP groups, with significantly lower readmission rates in the PP group (p = .004). In the sub-analysis, hospital readmissions between smokers and nonsmokers in the clozapine group were statistically significant (p = .027). Results may be influenced by use of a single hospital site, limits of a retrospective analysis, and variation in pharmaceutical preparation. Conclusion: PP may be a reasonable alternative to clozapine in severe schizophrenia for patients who continually resume smoking following discharge. Smoking may also be an important predictor of decompensation in smokers prescribed clozapine. A further prospective study is warranted.
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80
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Piwowarska J, Radziwoń-Zaleska M, Dmochowska M, Szepietowska E, Matsumoto H, Sygitowicz G, Pilc A, Łukaszkiewicz J. The usefulness of monitored therapy using Clozapine concentration in the blood serum for determining drug dose in Polish schizophrenic patients. Pharmacol Rep 2016; 68:1120-1125. [DOI: 10.1016/j.pharep.2016.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 11/27/2022]
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Ciprofloxacin and Clozapine: A Potentially Fatal but Underappreciated Interaction. Case Rep Psychiatry 2016; 2016:5606098. [PMID: 27872784 PMCID: PMC5107233 DOI: 10.1155/2016/5606098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 11/17/2022] Open
Abstract
Objective. Clozapine provides a 50%–60% response rate in refractory schizophrenia but has a narrow therapeutic index and is susceptible to pharmacokinetic interactions, particularly with strong inhibitors or inducers of cytochrome P450 (CYP) 1A2. Case Report. We report the case of a 28-year-old nonsmoking female with intellectual disability who was maintained for 3 years on clozapine 100 mg orally twice daily. The patient was treated for presumptive urinary tract infection with ciprofloxacin 500 mg orally twice daily and two days later collapsed and died despite resuscitation efforts. The postmortem femoral clozapine plasma level was dramatically elevated at 2900 ng/mL, and the cause of death was listed as acute clozapine toxicity. Conclusion. Given the potentially fatal pharmacokinetic interaction between clozapine and ciprofloxacin, clinicians are advised to monitor baseline clozapine levels prior to adding strong CYP450 1A2 inhibitors, reduce the clozapine dose by at least two-thirds if adding a 1A2 inhibitor such as ciprofloxacin, check subsequent steady state clozapine levels, and adjust the clozapine dose to maintain levels close to those obtained at baseline.
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82
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Kim E, Liu Y, Ben-Yoav H, Winkler TE, Yan K, Shi X, Shen J, Kelly DL, Ghodssi R, Bentley WE, Payne GF. Fusing Sensor Paradigms to Acquire Chemical Information: An Integrative Role for Smart Biopolymeric Hydrogels. Adv Healthc Mater 2016; 5:2595-2616. [PMID: 27616350 PMCID: PMC5485850 DOI: 10.1002/adhm.201600516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/26/2016] [Indexed: 12/14/2022]
Abstract
The Information Age transformed our lives but it has had surprisingly little impact on the way chemical information (e.g., from our biological world) is acquired, analyzed and communicated. Sensor systems are poised to change this situation by providing rapid access to chemical information. This access will be enabled by technological advances from various fields: biology enables the synthesis, design and discovery of molecular recognition elements as well as the generation of cell-based signal processors; physics and chemistry are providing nano-components that facilitate the transmission and transduction of signals rich with chemical information; microfabrication is yielding sensors capable of receiving these signals through various modalities; and signal processing analysis enhances the extraction of chemical information. The authors contend that integral to the development of functional sensor systems will be materials that (i) enable the integrative and hierarchical assembly of various sensing components (for chemical recognition and signal transduction) and (ii) facilitate meaningful communication across modalities. It is suggested that stimuli-responsive self-assembling biopolymers can perform such integrative functions, and redox provides modality-spanning communication capabilities. Recent progress toward the development of electrochemical sensors to manage schizophrenia is used to illustrate the opportunities and challenges for enlisting sensors for chemical information processing.
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Affiliation(s)
- Eunkyoung Kim
- Institute for Biosystems and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA
| | - Yi Liu
- Institute for Biosystems and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA
| | - Hadar Ben-Yoav
- Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Thomas E Winkler
- Institute for Systems Research, University of Maryland, College Park, MD, 20742, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Kun Yan
- School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, 430079, China
| | - Xiaowen Shi
- School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, 430079, China
| | - Jana Shen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD, 21201, USA
| | - Deanna L Kelly
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, 21228, USA
| | - Reza Ghodssi
- Institute for Systems Research, University of Maryland, College Park, MD, 20742, USA
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, 20742, USA
| | - William E Bentley
- Institute for Biosystems and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA
| | - Gregory F Payne
- Institute for Biosystems and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA.
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, 20742, USA.
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83
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Sugawara Y, Kikuchi Y, Yoneda M, Ohno-Shosaku T. Electrophysiological evidence showing muscarinic agonist-antagonist activities of N-desmethylclozapine using hippocampal excitatory and inhibitory neurons. Brain Res 2016; 1642:255-262. [PMID: 27048752 DOI: 10.1016/j.brainres.2016.03.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 03/25/2016] [Accepted: 03/31/2016] [Indexed: 11/18/2022]
Abstract
The atypical antipsychotic clozapine is widely used for treatment-resistant schizophrenic patients. Clozapine and its major active metabolite, N-desmethylclozapine (NDMC), have complex pharmacological properties, and interact with various neurotransmitter receptors. There are several biochemical studies reporting that NDMC exhibits a partial agonist profile at the human recombinant M1 muscarinic receptors. However, direct electrophysiological evidence showing the ability of NDMC to activate native M1 receptors in intact neurons is poor. Using rat hippocampal neurons, we previously demonstrated that activation of muscarinic receptors by a muscarinic agonist, oxotremorine M (oxo-M), induces a decrease in outward K(+)current at -40mV. In the present study, using this muscarinic current response we assessed agonist and antagonist activities of clozapine and NDMC at native muscarinic receptors in intact hippocampal excitatory and inhibitory neurons. Suppression of the oxo-M-induced current response by the M1 antagonist pirenzepine was evident only in excitatory neurons, while the M3 antagonist darifenacin was effective in both types of neurons. Muscarinic agonist activity of NDMC was higher than that of clozapine, higher in excitatory neurons than in inhibitory neurons, sensitive to pirenzepine, and partially masked when co-applied with clozapine. Muscarinic antagonist activity of clozapine as well as NDMC was not different between excitatory and inhibitory neurons, but clozapine was more effective than NDMC. These results demonstrate that NDMC has the ability to activate native M1 receptors expressed in hippocampal excitatory neurons, but its agonist activity might be limited in clozapine-treated patients because of the presence of excessive clozapine with muscarinic antagonist activity.
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Affiliation(s)
- Yuto Sugawara
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-0942, Japan
| | - Yui Kikuchi
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-0942, Japan
| | - Mitsugu Yoneda
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-0942, Japan
| | - Takako Ohno-Shosaku
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-0942, Japan.
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Wohkittel C, Gerlach M, Taurines R, Wewetzer C, Unterecker S, Burger R, Schreck D, Mehler-Wex C, Romanos M, Egberts K. Relationship between clozapine dose, serum concentration, and clinical outcome in children and adolescents in clinical practice. J Neural Transm (Vienna) 2016; 123:1021-31. [PMID: 27221285 DOI: 10.1007/s00702-016-1573-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/09/2016] [Indexed: 12/17/2022]
Abstract
Information on dose- and concentration-related clinical effects of clozapine treatment in children and adolescents is scarce. This study aimed to examine the relationship between dose, serum concentration, and clinical outcome as well as the influencing factors thereof in paediatric patients treated with clozapine. Data from a routine Therapeutic Drug Monitoring (TDM) service between 2004 and 2014 were studied in 68 patients, aged 11-18 years. Severity of illness, therapeutic effectiveness and adverse drug reactions (ADRs) were assessed by standardized means. A relationship between the daily dose (mean 319 mg, 4.9 mg/kg) and serum concentration (mean 387 ng/ml) of clozapine was found with the variation in dose explaining 30 % of the variability in clozapine serum concentrations. Also gender contributed to the variability, however, no influence of age or concomitant medications was detected. Furthermore, a significant association was found between clozapine serum concentration and the occurrence of ADRs. Patients without ADRs had a lower mean serum concentration than those with mild (261.4 vs 407.3 ng/ml, P = 0.018) and moderate ADRs (261.4 vs 416.3 ng/ml, P = 0.028). As clozapine was estimated to be effective in lower blood concentrations, guidance on a possibly lower therapeutic range of clozapine serum levels in paediatric patients is provided. With ADRs increasing under higher concentrations, TDM is strongly recommended in paediatric clozapine therapy for individualized dosing. Dose adjustment in females also might be reasonable according to gender-related differences in serum concentrations. However, regarding the limitations of this study results should be validated in larger studies with more standardized designs.
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Affiliation(s)
- Christopher Wohkittel
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany.
| | - Manfred Gerlach
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Regina Taurines
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Christoph Wewetzer
- Clinics of the City Cologne GmbH, Clinic for Child and Adolescent Psychiatry and Psychotherapy, Cologne, Germany
| | - Stefan Unterecker
- Department of Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Rainer Burger
- Department of Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Diana Schreck
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Claudia Mehler-Wex
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany.,HEMERA Private Hospital for Mental Health, Adolescents and Young Adults, Bad Kissingen, Germany.,Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Ulm, Ulm, Germany
| | - Marcel Romanos
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Karin Egberts
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Centre for Mental Health, University Hospital of Würzburg, Würzburg, Germany
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Predicting Weight Gain in Patients Treated With Clozapine: The Role of Sex, Body Mass Index, and Smoking. J Clin Psychopharmacol 2016; 36:120-4. [PMID: 26872115 DOI: 10.1097/jcp.0000000000000476] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Weight gain on clozapine is highly variable and poorly predictable. Its mechanisms are not well understood. This study explores the factors that predict weight gain between 3 and 12 months of clozapine therapy in community-dwelling patients. METHODS We conducted a retrospective audit of patients attending an outpatient clozapine clinic. Weight change from 3 to 12 months of therapy was recorded, expressed as a percentage of the 3-month weight. Univariate analyses compared percent weight change according to sex, smoking status, country of birth, and baseline body mass index. Correlations between weight gain, age, and clozapine dose were explored. A general linear model identified independent predictors of weight gain. RESULTS The mean weight change from 3 to 12 months in 117 patients was +3.1% (range, -17% to +30%). Females gained more weight than males (+5.5% vs +1.3%, P = 0.01), smokers gained more than nonsmokers (+5.1% vs +1.2%, P = 0.02), and obese patients gained less than normal or overweight individuals (0.15% vs 4.6% and 5.2%, respectively, P = 0.01). Age and clozapine dose had no relation to weight change. On multivariate analysis, baseline BMI and smoking status remained independent predictors of percent weight change in females. These 2 predictors explained 25% of weight change in females in the first 3 to 12 months of therapy. These associations were not observed in males. CONCLUSIONS We hypothesize that smoking affects weight change by promoting clozapine metabolism to norclozapine via cytochrome P450 enzymes. Verifying this hypothesis and exploring the mechanisms underpinning the sex dichotomy are areas for further research.
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Automated Analysis of Clozapine and Norclozapine in Human Plasma Using Novel Extraction Plate Technology and Flow-Injection Tandem Mass Spectrometry. Ther Drug Monit 2016; 38:42-9. [DOI: 10.1097/ftd.0000000000000231] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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87
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Ramos Perdigués S, Sauras Quecuti R, Mané A, Mann L, Mundell C, Fernandez-Egea E. An observational study of clozapine induced sedation and its pharmacological management. Eur Neuropsychopharmacol 2016; 26:156-161. [PMID: 26613638 DOI: 10.1016/j.euroneuro.2015.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/15/2015] [Accepted: 11/08/2015] [Indexed: 11/29/2022]
Abstract
Clozapine induced sedation is common but its management is unclear. We analyzed the factors associated with clozapine-induced sedation and the efficacy of common pharmacological strategies. We conducted a naturalistic observational study using two years electronic records of a cohort patients and three analyses: a cross sectional analysis of factors associated with total number of hours slept (as an objective proxy of sedation), and two prospective analyses of which factors were associated with changes in hours slept and the efficacy of two pharmacological strategies. 133 patients were included, of which 64.7% slept at least 9h daily. Among monotherapy patients (n=30), only norclozapine levels (r=.367, p=.03) correlated with hours slept. Using the prospective cohort (n=107), 42 patients decreased the number of hours slept, due to decreasing clozapine (40%) or augmenting with aripiprazole (36%). These two strategies were recommended to 22 (20.6%) and 23 (21.5%) subjects respectively but the majority (81.8% and 73.9%) did not reduce number of hours slept. Thus, pharmacological and non-pharmacological factors are involved in sedation. Norclozapine plasma levels correlated with total sleeping hours. Reducing clozapine and aripiprazole augmentation were associated to amelioration of sedation, although both strategies were effective only in a limited numbers of subjects.
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Affiliation(s)
- Sònia Ramos Perdigués
- Institut de Neuropsiquiatria i Adiccions, Parc de Salut Mar and Fundacio IMIM, Barcelona, Spain
| | - Rosa Sauras Quecuti
- Centre de Salut Mental Horta, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Anna Mané
- Institut de Neuropsiquiatria i Adiccions, Parc de Salut Mar and Fundacio IMIM, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Louisa Mann
- Cambridgeshire and Peterborough NHS Foundation Trust, UK
| | - Clare Mundell
- Cambridgeshire and Peterborough NHS Foundation Trust, UK
| | - Emilio Fernandez-Egea
- Cambridgeshire and Peterborough NHS Foundation Trust, UK; Department of Psychiatry, Behavioural and Clinical Neuroscience Institute (BCNI), University of Cambridge, UK; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain.
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88
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Clozapine-Induced Myocarditis: Prevention and Considerations in Rechallenge. PSYCHOSOMATICS 2015; 56:685-90. [DOI: 10.1016/j.psym.2015.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 06/26/2015] [Accepted: 07/06/2015] [Indexed: 11/17/2022]
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89
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90
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Ellison JC, Dufresne RL. A review of the clinical utility of serum clozapine and norclozapine levels. Ment Health Clin 2015. [DOI: 10.9740/mhc.2015.03.068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Treatment refractory schizophrenia is a serious issue affecting at least 30% of all patients with schizophrenia despite the continued emergence of new agents aimed at treating this disease. Clozapine therapy remains the most efficacious treatment for patients with schizophrenia who have failed two prior antipsychotics or those deemed an imminent harm to themselves or others. Because data are lacking on how to proceed if a patient should prove nonresponsive to clozapine therapy, the utmost care should be taken to ensure the optimization of clozapine. Therapeutic drug monitoring (TDM) is used with many other psychoactive agents to ensure the optimal therapeutic efficacy while minimizing adverse effects. The unique pharmacology of clozapine and the inter- and intraindividual variations in its pharmacokinetics make it a difficult agent with which to use TDM. The consensus is that 350 ng/mL is the lower threshold of therapeutic efficacy to define an adequate trial of clozapine. As of this writing, no clearly defined threshold exists for the upper limit of therapeutic efficacy or toxicity. TDM of clozapine can be useful in the following circumstances: when a clozapine-induced central nervous system toxicity is suspected, a medication that can inhibit or induce the metabolism of clozapine is being added or withdrawn, a change in smoking status has occurred, concerns for medication nonadherence are present, or decompensation while on a previously effective clozapine dosage is observed. The psychiatric pharmacist may play a crucial role in the interpretation and effective utilization of serum clozapine and norclozapine levels. This review will examine the current evidence for the clinical utility of monitoring serum levels of clozapine and its metabolites.
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91
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Anderson SG, Livingston M, Couchman L, Smith DJ, Connolly M, Miller J, Flanagan RJ, Heald AH. Sex differences in plasma clozapine and norclozapine concentrations in clinical practice and in relation to body mass index and plasma glucose concentrations: a retrospective survey. Ann Gen Psychiatry 2015; 14:39. [PMID: 26583040 PMCID: PMC4650861 DOI: 10.1186/s12991-015-0075-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/14/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Clozapine is widely prescribed and, although effective, can cause weight gain and dysglycemia. The dysmetabolic effects of clozapine are thought to be more prevalent in women with this gender on average attaining 17 % higher plasma clozapine concentrations than men. METHODS We investigated the relationship between dose, body mass index (BMI), plasma glucose concentration, and plasma clozapine and N-desmethylclozapine (norclozapine) concentrations in 100 individuals with a severe enduring mental illness. RESULTS Mean (10th/90th percentile) plasma clozapine concentrations were higher for women [0.49 (0.27-0.79) mg/L] compared with men [0.44 (0.26-0.70) mg/L] (F = 2.2; p = 0.035). There was no significant gender difference in the prescribed clozapine dose. BMI was significantly higher in women [mean (95 % CI) = 34.5 (26.0-45.3)] for females compared with 32.5 (25.2-41.0) for males. Overall, BMI increased by 0.7 kg/m(2) over a mean follow-up period of 210 days. A lower proportion, 41 % of women had a fasting blood glucose ≤6.0 mmol/L (<6.0 mmol/L is defined by the International Diabetes Federation as normal glucose handling), compared with 88 % of men (χ (2) = 18.6, p < 0.0001). CONCLUSIONS We have shown that mean BMI and blood glucose concentrations are higher in women prescribed clozapine than in men. Women also tended to attain higher plasma clozapine concentrations than men. The higher BMI and blood glucose in women may relate to higher tissue exposure to clozapine, as a consequence of sex differences in drug metabolism.
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Affiliation(s)
- Simon G Anderson
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK ; The George Institute for Global Health, Nuffield Department of Population Health, Oxford Martin School, University of Oxford, Oxford, UK
| | - Mark Livingston
- Department of Blood Sciences, Walsall Manor Hospital, Walsall, UK
| | - Lewis Couchman
- Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
| | - Daniel J Smith
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - Moira Connolly
- Intensive Psychiatric Care Unit, Gartnavel Royal Hospital, Glasgow, UK
| | - Joan Miller
- Pharmacy, Prestwich Hospital, Prestwich, Greater Manchester, UK
| | - Robert J Flanagan
- Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
| | - A H Heald
- Department of Medicine, Leighton Hospital, Crewe, CW1 4QJ UK ; School of Medicine and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
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92
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Beck K, McCutcheon R, Bloomfield MAP, Gaughran F, Reis Marques T, MacCabe J, Selvaraj S, Taylor D, Howes OD. The practical management of refractory schizophrenia--the Maudsley Treatment REview and Assessment Team service approach. Acta Psychiatr Scand 2014; 130:427-38. [PMID: 25201058 DOI: 10.1111/acps.12327] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/05/2014] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To describe a practical approach to the community management of treatment-resistant schizophrenia (TRS). METHOD A descriptive review of an approach to the assessment and management of patients with TRS, including the community titration of clozapine treatment, and a report of the management recommendations for the first one hundred patients assessed by the Treatment REview and Assessment Team (TREAT). RESULTS The standardized model for the community assessment, management and titration of clozapine is described. To date, 137 patients have been referred to this service and 100 patients (72%) attended for assessment. Of these, 33 have been initiated on clozapine while fifteen have had clozapine recommended but have not wished to undertake clozapine treatment. Other management options recommended have included augmentation strategies and long-acting injectable antipsychotics. CONCLUSION The service had increased the number of patients receiving community assessment and initiation of clozapine by five-fold relative to the rate prior to the establishment of the service. The large number of referrals and high attendance rate indicates that there is clinical demand for the model. Systematic evaluation is required to determine the clinical and cost-effectiveness of this model and its potential application to other clinical settings.
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Affiliation(s)
- K Beck
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK
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93
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Retrospective evaluation of therapeutic drug monitoring of clozapine and norclozapine in Belgium using a multidrug UHPLC–MS/MS method. Clin Biochem 2014; 47:336-9. [DOI: 10.1016/j.clinbiochem.2014.09.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/17/2014] [Accepted: 09/26/2014] [Indexed: 11/20/2022]
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94
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Lutz UC, Sirfy A, Wiatr G, Altpaß D, Farger G, Gasser T, Karle KN, Batra A. Clozapine serum concentrations in dopamimetic psychosis in Parkinson’s disease and related disorders. Eur J Clin Pharmacol 2014; 70:1471-6. [DOI: 10.1007/s00228-014-1772-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/08/2014] [Indexed: 11/29/2022]
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95
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Li CH, Stratford RE, Velez de Mendizabal N, Cremers TIFH, Pollock BG, Mulsant BH, Remington G, Bies RR. Prediction of brain clozapine and norclozapine concentrations in humans from a scaled pharmacokinetic model for rat brain and plasma pharmacokinetics. J Transl Med 2014; 12:203. [PMID: 25142323 PMCID: PMC4261612 DOI: 10.1186/1479-5876-12-203] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/08/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Clozapine is highly effective in treatment-resistant schizophrenia, although, there remains significant variability in the response to this drug. To better understand this variability, the objective of this study was to predict brain extracellular fluid (ECF) concentrations and receptor occupancy of clozapine and norclozapine in human central nervous system by translating plasma and brain ECF pharmacokinetic (PK) relationships in the rat and coupling these with known human disposition of clozapine in the plasma. METHODS Unbound concentrations of clozapine and norclozapine were measured in rat brain ECF using quantitative microdialysis after subcutaneous administration of a 10 mg/kg single dose of clozapine or norclozapine. These data were linked with plasma concentrations obtained in the same rats to develop a plasma-brain ECF compartmental model. Parameters describing brain ECF disposition were then allometrically scaled and linked with published human plasma PK to predict human ECF concentrations. Subsequently, prediction of human receptor occupancy at several CNS receptors was based on an effect model that related the predicted ECF concentrations to published concentration-driven receptor occupancy parameters. RESULTS A one compartment model with first order absorption and elimination best described clozapine and norclozapine plasma concentrations in rats. A delay in the transfer of clozapine and norclozapine from plasma to the brain ECF compartment was captured using a transit compartment model approach. Human clozapine and norclozapine concentrations in brain ECF were simulated, and from these the median percentage of receptor occupancy of dopamine-2, serotonin-2A, muscarinic-1, alpha-1 adrenergic, alpha-2 adrenergic and histamine-1 for clozapine, and dopamine-2 for norclozapine were consistent with values reported in the literature. CONCLUSIONS A PK model that relates clozapine and norclozapine disposition in rat plasma and brain, including blood-brain barrier transport, was developed. Using allometry and published human plasma PK, the model was successfully translated to predict clozapine and norclozapine concentrations and accordant receptor occupancy of both agents in human brain. These predicted exposure and occupancy measures at several receptors that bind clozapine may be employed to extend our understanding of clozapine's complex behavioral effects in humans.
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Affiliation(s)
| | | | | | | | | | | | | | - Robert R Bies
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 1001 W, 10th Street W7138, Indianapolis, IN 46202, USA.
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96
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Psychiatrists' Perspectives on Antipsychotic Dose and the Role of Plasma Concentration Therapeutic Drug Monitoring. Ther Drug Monit 2014; 36:486-93. [DOI: 10.1097/ftd.0000000000000041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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97
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Ben-Yoav H, Winkler TE, Kim E, Chocron SE, Kelly DL, Payne GF, Ghodssi R. Redox cycling-based amplifying electrochemical sensor for in situ clozapine antipsychotic treatment monitoring. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.03.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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98
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99
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Man WH, Ten Berg M, Wilting I, Huisman A, Cahn W, Douma JW, den Breeijen H, Heerdink ER, Egberts T, van Solinge W. Fluorescence of neutrophil granulocytes as a biomarker for clozapine use. Eur Neuropsychopharmacol 2013; 23:1408-13. [PMID: 24074821 DOI: 10.1016/j.euroneuro.2013.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/23/2013] [Accepted: 08/24/2013] [Indexed: 11/28/2022]
Abstract
Non-adherence to medication is a major issue in the treatment of schizophrenia in general and in particular for those treated with clozapine. A reliable tool to quantify patients long-term adherence to clozapine is currently unavailable. Enhanced FL3 neutrophil granulocyte fluorescence was serendipitously observed in a small population of schizophrenic patients treated with clozapine. The present study was aimed at assessing the association between clozapine use and FL3-fluorescence. A cross-sectional study was performed using data from the Utrecht Patient Oriented Database (UPOD). A total of 38,390 inpatients were included, of which 124 (0.33%) used clozapine. FL3-fluorescence was significantly higher (U=240,179, P<0.001) in clozapine users (mean (SD)=90.5 (11.8)) than in non-users (mean (SD)=69.8 (3.3)). Observed FL3-fluorescence was found to increase with increasing clozapine dose. The area under the receiver operating characteristic curve was 0.95. Our results confirm the association between use of clozapine and elevated FL3-fluorescence. Further research is needed to unravel the underlying mechanism and to investigate the true potential of FL3-fluorescence as a clozapine-adherence biomarker in clinical practice.
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Affiliation(s)
- Wai Hong Man
- Department of Clinical Pharmacy, University Medical Center Utrecht, The Netherlands
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100
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Zhang Q, Deng C, Huang XF. The role of ghrelin signalling in second-generation antipsychotic-induced weight gain. Psychoneuroendocrinology 2013; 38:2423-38. [PMID: 23953928 DOI: 10.1016/j.psyneuen.2013.07.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/17/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
Abstract
Based on clinical and animal studies, this review suggests a tri-phasic effect of second-generation antipsychotics (SGAs) on circulating ghrelin levels: an initial increase exerted by the acute effect of SGAs; followed by a secondary decrease possibly due to the negative feedback from the SGA-induced body weight gain or hyperphagia; and a final re-increase to reach the new equilibrium. Moreover, the results can also vary depending on individual SGAs, other hormonal states, dietary choices, and other confounding factors including medical history, co-treatments, age, gender, and ghrelin measurement techniques. Interestingly, rats treated with olanzapine, an SGA with high weight gain liabilities, are associated with increased hypothalamic ghrelin receptor (GHS-R1a) levels. In addition, expressions of downstream ghrelin signalling parameters at the hypothalamus, including neuropeptide Y (NPY)/agouti-related peptide (AgRP) and proopiomelanocortin (POMC) are also altered under SGA treatments. Thus, understanding the role of ghrelin signalling in antipsychotic drug-induced weight gain should offer potential novel pharmacological targets for tackling the obesity side-effect of SGAs and its associated metabolic syndrome.
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Affiliation(s)
- Qingsheng Zhang
- Centre for Translational Neuroscience, School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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