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Ruan CJ, Olmos I, Ricciardi C, Schoretsanitis G, Vincent PD, Anıl Yağcıoğlu AE, Eap CB, Baptista T, Clark SR, Fernandez-Egea E, Kim SH, Lane HY, Leung J, Maroñas Amigo O, Motuca M, Every-Palmer S, Procyshyn RM, Rohde C, Suhas S, Schulte PFJ, Spina E, Takeuchi H, Verdoux H, Correll CU, Molden E, De Las Cuevas C, de Leon J. Exploring low clozapine C/D ratios, inverted clozapine-norclozapine ratios and undetectable concentrations as measures of non-adherence in clozapine patients: A literature review and a case series of 17 patients from 3 studies. Schizophr Res 2024; 268:293-301. [PMID: 37487869 DOI: 10.1016/j.schres.2023.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 07/26/2023]
Abstract
BACKGROUND Up to 1/2 of outpatients prescribed clozapine may be partially/fully non-adherent, based on therapeutic drug monitoring (TDM). Three indices for measuring partial/full non-adherence are proposed a: 1) clozapine concentration/dose (C/D) ratio which drops to half or more of what is expected in the patient; 2) clozapine/norclozapine ratio that becomes inverted; and 3) clozapine concentration that becomes non-detectable. METHODS These 3 proposed indices are based on a literature review and 17 cases of possible non-adherence from 3 samples: 1) an inpatient study in a Chinese hospital, 2) an inpatient randomized clinical trial in a United States hospital, and 3) and a Uruguayan outpatient study. RESULTS The first index of non-adherence is a clozapine C/D ratio which is less than half the ratio corresponding to the patient's specific ancestry group and sex-smoking subgroup. Knowing the minimum therapeutic dose of the patient based on repeated TDM makes it much easier to establish non-adherence. The second index is inverted clozapine/norclozapine ratios in the absence of alternative explanations. The third index is undetectable concentrations. By using half-lives, the chronology of the 3 indices of non-adherence was modeled in two patients: 1) the clozapine C/D ratio dropped to ≥1/2 of what is expected from the patient (around day 2); 2) the clozapine/norclozapine ratio became inverted (around day 3); and 3) the clozapine concentration became undetectable by the laboratory (around days 9-11). CONCLUSION Prospective studies should further explore these proposed clozapine indices in average patients, poor metabolizers (3 presented) and ultrarapid metabolizers (2 presented).
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Affiliation(s)
- Can-Jun Ruan
- The National Clinical Research Centre for Mental Disorders & Beijing Key Lab of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China; Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.
| | - Ismael Olmos
- Clinical Pharmacology Unit and Pharmacy Department, Vilardebó Hospital, Administración de Servicios de Salud, Montevideo, Uruguay.
| | - Carina Ricciardi
- Clinical Pharmacology Unit and Outpatient Clinic, Vilardebó Hospital, Administración de Servicios de Salud, Montevideo, Uruguay.
| | - Georgios Schoretsanitis
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland; The Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, New York, USA; Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA.
| | - Philippe D Vincent
- Department of Pharmacy, Institut Universitaire en Santé Mentale de Montréal (IUSMM), Montreal, Canada; Faculty of Pharmacy, Université de Montréal, Montreal, Canada; IUSMM Research Center, Montreal, Canada.
| | | | - Chin B Eap
- Unit of Pharmacogenetics and Clinical Psychopharmacology, Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland; School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland; Center for Research and Innovation in Clinical Pharmaceutical Sciences, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland; Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, University of Lausanne, Geneva, Switzerland.
| | - Trino Baptista
- Department of Physiology, Los Andes University Medical School, Mérida, Venezuela; Medical School, Anáhuac University, Querétaro, Mexico; Neuroorigen, Querétaro, Mexico.
| | - Scott R Clark
- University of Adelaide, Discipline of Psychiatry, Adelaide, Australia.
| | - Emilio Fernandez-Egea
- Department of Psychiatry, University of Cambridge, Cambridge, UK; Cambridgeshire and Peterborough NHS Foundation Trust, Fulbourn Hospital, Fulbourn, Cambridge, UK.
| | - Se Hyun Kim
- Department of Psychiatry, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Hsien-Yuan Lane
- Department of Psychiatry and Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan; Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan.
| | - Jonathan Leung
- Department of Pharmacy, Mayo Clinic, Rochester, MN, USA.
| | - Olalla Maroñas Amigo
- Genomic Medicine Group, Galician Public Foundation of Genomic Medicine (FPGMX), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Galicia, Spain; Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain; Center for Biomedical Research in Rare Diseases Network, Carlos III Health Institute, Madrid, Spain.
| | - Mariano Motuca
- Department of Psychiatry, School of Medicine at Universidad Nacional de Cuyo, Mendoza, Argentina.
| | - Susanna Every-Palmer
- Department of Psychological Medicine, University of Otago Wellington, Wellington, New Zealand.
| | - Ric M Procyshyn
- Department of Psychiatry, University of British Columbia, Vancouver, Canada; British Columbia Mental Health and Substance Use Services Research Institute, Vancouver, Canada.
| | - Christopher Rohde
- Department of Affective Disorders, Aarhus University Hospital - Psychiatry, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Satish Suhas
- Department of Psychiatry, National Institute of Mental Health and Neurosciences [NIMHANS], Bangalore, India.
| | - Peter F J Schulte
- Mental Health Services Noord-Holland-Noord, Alkmaar, Netherlands; Dutch Clozapine Collaboration Group, Castricum, Netherlands.
| | - Edoardo Spina
- Department of Clinical and Experimeta Medicine, University of Messina, Messina, Italy.
| | - Hiroyoshi Takeuchi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
| | - Hélène Verdoux
- Université Bordeaux, Inserm, Bordeaux Population Health Research Center, Team Pharmacoepidemiology, UMR 1219, F-33000 Bordeaux, France.
| | - Christoph U Correll
- The Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, New York, USA; Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA; Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany.
| | - Espen Molden
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway; Department of Pharmacy, University of Oslo, Oslo, Norway.
| | - Carlos De Las Cuevas
- Department of Internal Medicine, Dermatology and Psychiatry, School of Medicine, University of La Laguna, Canary Islands, Spain; Instituto Universitario de Neurociencia (IUNE), Universidad de La Laguna, San Cristóbal de La Laguna, Spain.
| | - Jose de Leon
- Mental Health Research Center, Eastern State Hospital, Lexington, KY, USA; Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apóstol Hospital, University of the Basque Country, Vitoria, Spain.
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Mach A, Wnorowska A, Siwek M, Wojnar M, Radziwoń-Zaleska M. Clinical and pharmacological factors influencing serum clozapine and norclozapine levels. Front Pharmacol 2024; 15:1356813. [PMID: 38601469 PMCID: PMC11004283 DOI: 10.3389/fphar.2024.1356813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/15/2024] [Indexed: 04/12/2024] Open
Abstract
Background Clozapine (CLO) is a very effective antipsychotic, whose use is associated with dose-dependent risk of complications. Due to high interindividual variability in CLO metabolism, there is a need to identify factors affecting the blood concentrations of CLO and its active metabolite, norclozapine (NCLO). Methods A total of 446 blood samples (collected from 233 women and 213 men, aged from 18 to 77 years) were included in this study and analyzed for CLO and NCLO concentrations. The patients were treated at a psychiatric hospital in Warsaw in the years 2016-2021. Serum CLO and NCLO concentrations were determined with high-performance liquid chromatography coupled to UV. Results The following factors were shown to increase serum CLO and NCLO levels: higher CLO dose (p < 0.001), female sex (p < 0.001), nonsmoker status (p < 0.001), the use of more than two additional psychotropic drugs (only in the case of CLO; p = 0.046), concomitant use of beta-blockers (for CLO p = 0.049; for NCLO p < 0.001), and older age (for CLO p < 0.001; for NCLO p = 0.011). Despite the use of CLO at daily doses within the recommended range (200-450 mg), the evaluated serum CLO and NCLO levels were within the therapeutic ranges in only 37% and 75% of cases, respectively, with 5.6% of cases exceeding the CLO toxicity threshold. Discussion The use of CLO at recommended doses does not guarantee achieving therapeutic concentrations of CLO or NCLO. Women and nonsmokers were at the highest risk of having toxic CLO levels.
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Affiliation(s)
- Anna Mach
- Department of Psychiatry, Medical University of Warsaw, Warsaw, Poland
| | - Anna Wnorowska
- Department of Psychiatry, Medical University of Warsaw, Warsaw, Poland
| | - Marcin Siwek
- Department of Affective Disorders, Jagiellonian University Medical College, Cracow, Poland
| | - Marcin Wojnar
- Department of Psychiatry, Medical University of Warsaw, Warsaw, Poland
- Department of Psychiatry, Addiction Center, University of Michigan, Ann Arbor, MI, United States
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3
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Reeves S, Bertrand J, Obee SJ, Hunter S, Howard R, Flanagan RJ. A population pharmacokinetic model to guide clozapine dose selection, based on age, sex, ethnicity, body weight and smoking status. Br J Clin Pharmacol 2024; 90:135-145. [PMID: 36793249 DOI: 10.1111/bcp.15691] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 02/02/2023] [Accepted: 02/05/2023] [Indexed: 02/17/2023] Open
Abstract
AIMS Guidance on clozapine dosing in treatment-resistant schizophrenia is based largely on data from White young adult males. This study aimed to investigate the pharmacokinetic profiles of clozapine and N-desmethylclozapine (norclozapine) across the age range, accounting for sex, ethnicity, smoking status and body weight. METHODS A population pharmacokinetic model, implemented in Monolix, that linked plasma clozapine and norclozapine via a metabolic rate constant, was used to analyse data from a clozapine therapeutic drug monitoring service, 1993-2017. RESULTS There were 17 787 measurements from 5960 patients (4315 male) aged 18-86 years. The estimated clozapine plasma clearance was reduced from 20.2 to 12.0 L h-1 between 20 and 80 years. Model-based dose predictions to attain a predose plasma clozapine concentration of 0.35 mg L-1 was 275 (90% prediction interval 125, 625) mg day-1 in nonsmoking, White males weighing 70 kg and aged 40 years. The corresponding predicted dose was increased by 30% in smokers, decreased by 18% in females, and was 10% higher and 14% lower in otherwise analogous Afro-Caribbean and Asian patients, respectively. Overall, the predicted dose decreased by 56% between 20 and 80 years. CONCLUSION The large sample size and wide age range of the patients studied allowed precise estimation of dose requirements to attain predose clozapine concentration of 0.35 mg L-1 . The analysis was, however, limited by the absence of data on clinical outcome and future studies are required to determine optimal predose concentrations specifically in those aged over 65 years.
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Affiliation(s)
- Suzanne Reeves
- Division of Psychiatry, University College London, London, UK
| | - Julie Bertrand
- Institute of Genetics, University College London, London, UK
- UMR 1137 Infection, Antimicrobials, Modelling, Evolution (IAME) French Institute for Medical Research (INSERM), University of Paris, Paris, France
| | - Stephen John Obee
- Precision Medicine, Networked Services, Bessemer Wing, King's College Hospital NHS Foundation Trust, London, UK
| | - Samora Hunter
- Precision Medicine, Networked Services, Bessemer Wing, King's College Hospital NHS Foundation Trust, London, UK
| | - Robert Howard
- Division of Psychiatry, University College London, London, UK
| | - Robert James Flanagan
- Precision Medicine, Networked Services, Bessemer Wing, King's College Hospital NHS Foundation Trust, London, UK
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4
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Flanagan RJ, Gee S, Belsey S, Couchman L, Lally J. Therapeutic monitoring of plasma clozapine and N-desmethylclozapine (norclozapine): practical considerations. BJPSYCH ADVANCES 2023. [DOI: 10.1192/bja.2022.71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
SUMMARY
Clozapine dose assessment in treatment-refractory schizophrenia is complicated. There is a narrow margin between an effective and a potentially toxic dose and wide inter-individual variation in clozapine metabolic capacity. Moreover, factors such as changes in smoking habit, infection/inflammation, co-prescription of certain drugs, notably fluvoxamine, and age alter the dose requirement within individuals. Therapeutic drug monitoring (TDM) of plasma clozapine and N-desmethylclozapine (norclozapine) can help assess adherence, guide dosage and guard against toxicity. This article gives an overview of clozapine pharmacokinetics and factors affecting clozapine dose requirements. It then outlines the procedures and processes of clozapine TDM, from taking the blood sample for laboratory assay or point-of-contact (finger-prick) testing (POCT) to interpreting and acting on the results.
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5
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Handley SA, Every-Palmer S, Ismail A, Flanagan RJ. Clozapine-induced gastrointestinal hypomotility: presenting features and outcomes, UK pharmacovigilance reports, 1992-2017. Br J Psychiatry 2022; 220:1-9. [PMID: 35164895 DOI: 10.1192/bjp.2022.24] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Clozapine-induced gastrointestinal hypomotility (CIGH) affects some 75% of patients treated with clozapine. AIMS To document the incidence of potentially harmful CIGH in the UK. METHOD We studied spontaneous UK pharmacovigilance reports recorded as clozapine-related gastrointestinal adverse drug reactions, 1992-2017. RESULTS There were 527 patients reported with potentially harmful CIGH; 33% (n = 172) died. Deaths averaged 1 per year 1992-1999, 5 per year 2000-2009 and 15 per year 2010-2017. Those who died were older (median 52 years v. 49 years) and had been prescribed clozapine for longer than those who recovered (median 11.3 years v. 4.8 years), but there was no difference in prescribed dose. Within the first 4 years of clozapine treatment, there were 169 reports of CIGH, of which 3% (n = 5) were fatal. At 10-14 years there were 63 reports of CIGH, of which 25% (n = 16) were fatal. Among the deaths, males were younger (median 51, range 22-89 v. median 57, range 24-89 years) with higher clozapine doses (median 450, range 100-900 v. median 300, range 12.5-800 mg/d) than females. In non-fatal CIGH, surgery was the most frequent outcome (n = 92). The procedures included appendectomy, ileostomy, total/partial colectomy, colostomy/stoma and proctosigmoidectomy. Clozapine dosage was reduced in 6 patients, stopped and restarted in 23, 'continued' in 6 and discontinued permanently in at least 76 patients. CONCLUSIONS The risk of serious morbidity/mortality from CIGH is substantial. The need to actively monitor bowel function and give laxatives to patients treated with clozapine is clear.
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Affiliation(s)
- S A Handley
- Department of Pathology, Royal Hobart Hospital, Australia
| | - S Every-Palmer
- Department of Psychological Medicine, University of Otago, New Zealand
| | - A Ismail
- Manor Drive Medical Centre and West Barnes Surgery, UK and Medicines and Healthcare Products Regulatory Agency, UK
| | - R J Flanagan
- Precision Medicine, Networked Services, King's College Hospital, UK
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6
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Marasca C, Mandrioli R, Sardella R, Vovk T, Armirotti A, Cavalli A, Serretti A, Protti M, Mercolini L. Dried Volumetric Microsampling Approaches for the Therapeutic Drug Monitoring of Psychiatric Patients Undergoing Clozapine Treatment. Front Psychiatry 2022; 13:794609. [PMID: 35722565 PMCID: PMC9198272 DOI: 10.3389/fpsyt.2022.794609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 04/20/2022] [Indexed: 01/18/2023] Open
Abstract
Clozapine is one of the most widely used second-generation antipsychotic drugs (SGAs) for the treatment of schizophrenia. Despite advantages over first-generation drugs, clozapine still shows significant side effects and interindividual variations in efficacy. In order to ensure frequent therapeutic drug monitoring (TDM) and improve the compliance of psychiatric patients undergoing clozapine treatment, two novel dried microsampling approaches based on whole blood and plasma volumetric absorptive microsampling (b-VAMS and p-VAMS) and microfluidic generated-dried blood spot technology (mfDBS) were developed and coupled to HPLC with electrochemical detection (ED). The proposed miniaturized strategies by means of VAMS and microfluidic channel-based devices provide several advantages in terms of collection, storage, and handling compared to classical blood and plasma processing. Satisfactory validation results were obtained for all microsampling platforms, with mean extraction yields >85.1%, precision as relative standard deviation (RSD) < 5.1%, and stability < 4.5% analyte loss after 30 days for p-VAMS; mean extraction yields > 83.4%, precision RSD < 5.4%, and stability < 4.6% analyte loss after 30 days for b-VAMS, and mean extraction yields > 74.0%, precision RSD < 5.6%, and stability < 4.9% analyte loss after 30 days for mfDBS. The original microsampling methodologies have been successfully applied to the blood and plasma collected from five psychiatric patients for the monitoring of the levels of clozapine and its main metabolites, providing robust and reliable quali-quantitative results. Comparisons between results of the two dried microsampling technologies with those obtained by classic fluid plasma analysis were in good agreement and have demonstrated that the proposed miniaturized approaches could be suitable for TDM purposes.
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Affiliation(s)
- Camilla Marasca
- Research Group of Pharmaco-Toxicological Analysis (PTA Lab), Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy.,Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia (IIT), Genoa, Italy
| | - Roberto Mandrioli
- Department for Life Quality Studies (QuVi), Alma Mater Studiorum - University of Bologna, Rimini, Italy
| | - Roccaldo Sardella
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Tomaž Vovk
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Andrea Armirotti
- Analytical Chemistry Lab, Fondazione Istituto Italiano di Tecnologia (IIT), Genoa, Italy
| | - Andrea Cavalli
- Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Alessandro Serretti
- Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Michele Protti
- Research Group of Pharmaco-Toxicological Analysis (PTA Lab), Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Laura Mercolini
- Research Group of Pharmaco-Toxicological Analysis (PTA Lab), Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy
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7
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Clinical and genetic influencing factors on clozapine pharmacokinetics in Tunisian schizophrenic patients. THE PHARMACOGENOMICS JOURNAL 2021; 21:551-558. [PMID: 33731885 DOI: 10.1038/s41397-021-00231-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 02/04/2021] [Accepted: 02/22/2021] [Indexed: 02/02/2023]
Abstract
Clozapine (Clz) is an atypical antipsychotic, which its pharmacokinetics can be influenced by several factors. The CYP1A2 and CYP2C19, major enzymes implicated in Clz metabolism, present an interethnic variation on their activity caused by single nucleotide polymorphisms (SNPs). The present study investigated the influence of genetic and nongenetic factors on Clz pharmacokinetics in a southern Mediterranean population. We included adult Tunisian schizophrenic patients having received Clz and undergone a therapeutic drug monitoring (TDM) of Clz by morning C0 monitoring. The genomic DNA was extracted using a salting-out procedure. CYP1A2*1F (rs762551;-163C>A), CYP1A2*1C (rs2069514;-3860 G>A) and CYP 2C19*2 (rs4244285; 681G>A) was analyzed using PCR-RFLP. Fifty-one patients were enrolled in the study. The mutant allele (CYP1A2*1F) was the most frequently detected (58.8%). For CYP1A2*1F, Clz dose-normalized (C0/D ratio) was as high as 1.28 ± 0.37 in CC versus 0.67 ± 0.32 ng mL-1 per mg day-1 in AA group (p < 0.001). The influence of genetic (CYP1A2*1F, CYP1A2*1C and CYP2C19*2) and nongenetic parameters (age, weight, gender, tobacco, coffee, and alcohol consumption) on the variation of the Clz C0/D ratio was investigated. Only the CYP1A2*1 F polymorphism correlates significantly with the Clz C0/D variation and could explain 24% of its variability. Our data support a critical role of the CYP1A2 -163C>A on the variation of Clz exposure in Tunisian schizophrenic patients. Considering its narrow therapeutic range, CYP1A2 genotyping combined with TDM of Clz may improve efficacy and safety of this drug. Further studies are needed to investigate this issue.
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Taylor D, Atkins M, Harland R, Baburina I, MacCabe JH, Salamone SJ, McGuire P. Point-of-care measurement of clozapine concentration using a finger-stick blood sample. J Psychopharmacol 2021; 35:279-283. [PMID: 33579175 DOI: 10.1177/0269881121991567] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The use of clozapine demands regular monitoring of clozapine plasma concentrations and of white blood cell parameters. The delay between sending blood samples for analysis and receiving the results hinders clinical care. Point-of-care testing (POCT) can provide drug assay results within a few minutes. AIM This study aimed to investigate the utility of a novel point-of-care device that can measure clozapine concentrations using capillary blood samples collected via a finger stick. METHOD During a five-week period starting in June 2019 eligible patients were asked to provide a finger-stick capillary sample in addition to their usual venous blood sample. Samples were analysed by the novel point-of-care device and by the standard laboratory method. Capillary blood samples were tested by the MyCare™ Insite POCT analyser, and a quantitative measurement of clozapine concentration was provided within six minutes. RESULTS A total of 309 patients agreed to measurements by the two methods. Analysis revealed clozapine concentrations in venous blood as determined by the laboratory method ranged from 20 to 1310 ng/mL and by POCT from 7 to 1425 ng/mL. There was a strong positive correlation (R = 0.89) between the results from the venous and the capillary sample methods. The slope of the association between standard assay and MyCare™ Insite was 1.0 with an intercept of -21 ng/mL, indicating minimal bias. CONCLUSION Clozapine concentrations can be accurately measured at the point of care using capillary blood samples collected via a finger stick. This approach may be more acceptable than venous sampling to patients and, with almost instant results available, more useful to clinicians.
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Affiliation(s)
- David Taylor
- Pharmacy Department, South London and Maudsley NHS Foundation Trust, London, UK.,Institute of Pharmaceutical Science, King's College London, London, UK
| | - Matthew Atkins
- Institute of Pharmaceutical Science, King's College London, London, UK.,Pathology Department, South London and Maudsley NHS Foundation Trust, London, UK
| | - Robert Harland
- South London and Maudsley NHS Foundation Trust, London, UK
| | | | - James H MacCabe
- Institute of Psychiatry, Psychology and Neuroscience, King�s College London, London, UK
| | | | - Philip McGuire
- Institute of Psychiatry, Psychology and Neuroscience, King�s College London, London, UK
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Martini F, Spangaro M, Buonocore M, Bechi M, Cocchi F, Guglielmino C, Bianchi L, Sapienza J, Agostoni G, Mastromatteo A, Bosia M, Cavallaro R. Clozapine tolerability in Treatment Resistant Schizophrenia: exploring the role of sex. Psychiatry Res 2021; 297:113698. [PMID: 33440269 DOI: 10.1016/j.psychres.2020.113698] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/28/2020] [Indexed: 12/20/2022]
Abstract
Clozapine is the only evidence-based drug indicated for Treatment Resistant Schizophrenia but it is largely underprescribed, partially due to its life-threatening adverse effects (AEs). However, clozapine treatment is burdened by other common AEs as constipation, hypersalivation, postural hypotension, tachycardia and metabolic abnormalities. Few studies have investigated sex-related differences in clozapine's tolerability, reporting women to experience more frequently weight gain, hyperglycemia and constipation, while men hypertension and dyslipidemia. Based on these premises, we investigated clinical, psychopathological and metabolic sex-related differences among 147 treatment-resistant patients treated with clozapine, with a specific focus on non-life-threatening AEs. We observed significant higher prevalence of tachycardia in men, and of orthostatic hypotension and constipation in women. Concerning metabolic alterations, we observed significant lower levels of HDL-cholesterol and higher prevalence of hypertriglyceridemia among men, whereas females showed higher prevalence of abdominal obesity. Consistently with previous studies, our data confirm the presence of sex-related differences in clozapine tolerability, with a main effect of sex especially for tachycardia, postural hypotension and constipation. Although non-life-threatening, these common AEs significantly affect patients' quality of life, undermine compliance and cause treatment discontinuation. A better understanding of this topic could contribute to tailor therapeutic approaches, thus improving tolerability, compliance and clinical stability.
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Affiliation(s)
- Francesca Martini
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy.
| | - Marco Spangaro
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
| | - Mariachiara Buonocore
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Margherita Bechi
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federica Cocchi
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Carmelo Guglielmino
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Laura Bianchi
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | | | - Antonella Mastromatteo
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marta Bosia
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
| | - Roberto Cavallaro
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
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10
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Ortega-Vázquez A, Mayen-Lobo YG, Dávila-Ortiz de Montellano DJ, Tristán-López L, Aviña-Cervantes CL, Ríos C, López-López M, Monroy-Jaramillo N. Alcohol intake potentiates clozapine adverse effects associated to CYP1A2*1C in patients with refractory psychosis. Drug Dev Res 2020; 82:685-694. [PMID: 33336447 DOI: 10.1002/ddr.21774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/24/2020] [Accepted: 12/03/2020] [Indexed: 12/24/2022]
Abstract
Clozapine (CLZ) is an atypical antipsychotic and the gold standard for refractory psychosis treatment. However, there is little information regarding pharmacogenetics of CLZ in patients with refractory psychosis and its clinical correlation with alcohol intake. Although neurological effects of CLZ in patients with concomitant alcohol intake are documented, its use is very common in patients with psychosis. We explored the impact of CYP1A2, CYP2D6, CYP2C19, and CYP3A4 genetic variants on CLZ pharmacokinetics and side effects, along with coffee/alcohol/tobacco consumption habits and clinical data of 48 adult patients with refractory psychosis on CLZ antipsychotic monotherapy. Relevant CYP variants in CLZ metabolism were evaluated by targeted genotyping and multiplex ligation-dependent probe amplification. CLZ and its main metabolite plasma concentrations were determined by high performance liquid chromatography. Biochemical and molecular data, along with other potential confounders, were included in the analysis by linear regression. Overall, CYP variants showed no effect on CLZ pharmacokinetics. The rs2069514 variant in homozygous genotype (also known as CYP1A2*1C/*1C) was associated with CLZ adverse reactions in Mexican patients with refractory psychosis (OR = 3.55 CI95 = 1.041-12.269, p = .043) and demonstrated that this effect is doubled by concomitant alcohol consumption (OR = 7.9 CI95 = 1.473-42.369, p = .016). Clinicians should be aware of this information before starting CLZ use, when treating patients with refractory psychosis, who are alcohol drinkers and carriers of this genetic variant in order to prevent CLZ-related adverse reactions. Nevertheless, our findings should be replicated in larger samples.
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Affiliation(s)
- Alberto Ortega-Vázquez
- Department of Biological Systems, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico
| | - Yerye G Mayen-Lobo
- Department of Biological Systems, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico.,Master's Program in Pharmaceutical Sciences, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico
| | | | - Luis Tristán-López
- Department of Neurochemistry, National Institute of Neurology and Neurosurgery, "Manuel Velasco Suárez", Mexico City, Mexico
| | - Carlos L Aviña-Cervantes
- Department of Psychiatry, National Institute of Neurology and Neurosurgery, "Manuel Velasco Suárez", Mexico City, Mexico
| | - Camilo Ríos
- Department of Biological Systems, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico.,Master's Program in Pharmaceutical Sciences, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico.,Department of Neurochemistry, National Institute of Neurology and Neurosurgery, "Manuel Velasco Suárez", Mexico City, Mexico
| | - Marisol López-López
- Department of Biological Systems, Metropolitan Autonomous University-Xochimilco, Mexico City, Mexico
| | - Nancy Monroy-Jaramillo
- Department of Genetics, National Institute of Neurology and Neurosurgery, "Manuel Velasco Suárez", Mexico City, Mexico
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11
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Wagner E, McMahon L, Falkai P, Hasan A, Siskind D. Impact of smoking behavior on clozapine blood levels - a systematic review and meta-analysis. Acta Psychiatr Scand 2020; 142:456-466. [PMID: 32869278 DOI: 10.1111/acps.13228] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/14/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Tobacco smoking significantly impacts clozapine blood levels and has substantial implications on individual efficacy and safety outcomes. By investigating differences in clozapine blood levels in smoking and non-smoking patients on clozapine, we aim to provide guidance for clinicians how to adjust clozapine levels for patients on clozapine who change their smoking habits. METHODS We conducted a meta-analysis on clozapine blood levels, norclozapine levels, norclozapine/clozapine ratios, and concentration to dose (C/D) ratios in smokers and non-smokers on clozapine. Data were meta-analyzed using a random-effects model with sensitivity analyses on dose, ethnic origin, and study quality. RESULTS Data from 23 studies were included in this meta-analysis with 21 investigating differences between clozapine blood levels of smokers and non-smokers. In total, data from 7125 samples were included for the primary outcome (clozapine blood levels in ng/ml) in this meta-analysis. A meta-analysis of all between-subject studies (N = 16) found that clozapine blood levels were significantly lower in smokers compared with non-smokers (Standard Mean Difference (SMD) -0.39, 95% confidence interval (CI) -0.55 to -0.22, P < 0.001, I2 = 80%). With regard to the secondary outcome, C/D ratios (N = 16 studies) were significantly lower in the smoker group (n = 645) compared with the non-smoker group (n = 813; SMD -0.70, 95%CI -0.84 to -0.56, P < 0.00001, I2 = 17%). CONCLUSION Smoking behavior and any change in smoking behavior is associated with a substantial effect on clozapine blood levels. Reductions of clozapine dose of 30% are recommended when a patient on clozapine stops smoking. Reductions should be informed by clozapine steady-state trough levels and a close clinical risk-benefit evaluation.
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Affiliation(s)
- E Wagner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - L McMahon
- School of Medicine, University of Queensland, Brisbane, Australia
| | - P Falkai
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - A Hasan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics of the University Augsburg, Bezirkskrankenhaus Augsburg, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - D Siskind
- School of Medicine, University of Queensland, Brisbane, Australia.,Metro South Addiction and Mental Health Service, Brisbane, Australia
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12
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Flanagan RJ, Lally J, Gee S, Lyon R, Every-Palmer S. Clozapine in the treatment of refractory schizophrenia: a practical guide for healthcare professionals. Br Med Bull 2020; 135:73-89. [PMID: 32885238 PMCID: PMC7585831 DOI: 10.1093/bmb/ldaa024] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/18/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Clozapine remains the only medication licensed for treating refractory schizophrenia. However, it remains underutilized in part due to concerns regarding adverse events. SOURCES OF DATA Published literature. AREAS OF AGREEMENT Common adverse events during clozapine treatment include sedation, hypersalivation, postural hypotension, dysphagia, gastrointestinal hypomotility, weight gain, diabetes mellitus and dyslipidaemia. Rare but serious events include agranulocytosis, cardiomyopathy, myocarditis, pneumonia, paralytic ileus and seizure. AREAS OF CONTROVERSY It remains unclear how best to minimize clozapine-induced morbidity/mortality (i) during dose titration, (ii) from hypersalivation and (iii) from gastrointestinal hypomotility. It is also unclear how clozapine pharmacokinetics are affected by (i) gastrointestinal hypomotility, (ii) systemic infection and (iii) passive exposure to cigarette smoke. Whether monthly haematological monitoring needs to continue after 12 months of uninterrupted therapy is also a subject of debate. GROWING POINTS There is a need for better management of serious clozapine-related adverse events in addition to agranulocytosis. There is also a need for better education of patients and carers, general practitioners, A&E and ITU staff and others of the problems posed in using clozapine safely. AREAS TIMELY FOR DEVELOPING RESEARCH There is a need for more research on assessing clozapine dosage (i) as patients get older, (ii) with respect to exposure to cigarette smoke and (iii) optimizing response if adverse events or other factors limit dosage.
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Affiliation(s)
- R J Flanagan
- Precision Medicine, Networked Services, Bessemer Wing, King's College Hospital NHS Foundation Trust, Denmark Hill, London SE5 9RS, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| | - J Lally
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.,Department of Psychiatry, Mater Misericordiae University Hospital, 63 Eccles Street, Dublin 7, Ireland.,Department of Psychiatry, Royal College of Surgeons in Ireland, 123 St Stephen's Green, Dublin 2, Ireland
| | - S Gee
- Pharmacy Department, South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, UK
| | - R Lyon
- Department of Pharmacy, Sussex Partnership NHS Foundation Trust, Chichester Centre, Graylingwell Drive, Chichester, West Sussex PO19 6GS UK
| | - S Every-Palmer
- Department of Psychological Medicine, University of Otago, Wellington, PO Box 7343, Newtown, Wellington 6242, NZ
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13
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Albitar O, Harun SN, Zainal H, Ibrahim B, Sheikh Ghadzi SM. Population Pharmacokinetics of Clozapine: A Systematic Review. BIOMED RESEARCH INTERNATIONAL 2020; 2020:9872936. [PMID: 31998804 PMCID: PMC6970501 DOI: 10.1155/2020/9872936] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/10/2019] [Accepted: 12/19/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVE Clozapine is a second-generation antipsychotic drug that is considered the most effective treatment for refractory schizophrenia. Several clozapine population pharmacokinetic models have been introduced in the last decades. Thus, a systematic review was performed (i) to compare published pharmacokinetics models and (ii) to summarize and explore identified covariates influencing the clozapine pharmacokinetics models. METHODS A search of publications for population pharmacokinetic analyses of clozapine either in healthy volunteers or patients from inception to April 2019 was conducted in PubMed and SCOPUS databases. Reviews, methodology articles, in vitro and animal studies, and noncompartmental analysis were excluded. RESULTS Twelve studies were included in this review. Clozapine pharmacokinetics was described as one-compartment with first-order absorption and elimination in most of the studies. Significant interindividual variations of clozapine pharmacokinetic parameters were found in most of the included studies. Age, sex, smoking status, and cytochrome P450 1A2 were found to be the most common identified covariates affecting these parameters. External validation was only performed in one study to determine the predictive performance of the models. CONCLUSIONS Large pharmacokinetic variability remains despite the inclusion of several covariates. This can be improved by including other potential factors such as genetic polymorphisms, metabolic factors, and significant drug-drug interactions in a well-designed population pharmacokinetic model in the future, taking into account the incorporation of larger sample size and more stringent sampling strategy. External validation should also be performed to the previously published models to compare their predictive performances.
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Affiliation(s)
- Orwa Albitar
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, George Town, Penang, Malaysia
| | - Sabariah Noor Harun
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, George Town, Penang, Malaysia
| | - Hadzliana Zainal
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, George Town, Penang, Malaysia
| | - Baharudin Ibrahim
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, George Town, Penang, Malaysia
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14
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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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15
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Qurashi I, Stephenson P, Nagaraj C, Chu S, Drake R, Couchman L, Flanagan R. Changes in smoking status, mental state and plasma clozapine concentration: retrospective cohort evaluation. BJPsych Bull 2019; 43:271-274. [PMID: 31391141 PMCID: PMC8058886 DOI: 10.1192/bjb.2019.50] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
AIMS AND METHOD To investigate the percentage of patients who commenced smoking after transferring out of a non-smoking forensic psychiatric unit, the corresponding clozapine dose adjustments, the effects on plasma clozapine/norclozapine concentrations and observed changes in mental state. We reviewed the notes and plasma clozapine/norclozapine concentrations of 46 patients transferred to medium secure units between July 2008 and December 2013. RESULTS Thirty-five patients commenced smoking. Their median clozapine dose was increased by 50 mg/d. In the non-smokers, the median clozapine dose remained unchanged. Plasma clozapine/norclozapine concentrations were significantly reduced in smokers despite dosage adjustment. Eighteen patients experienced deterioration in mental state after transfer; almost all these patients were smokers. CLINICAL IMPLICATIONS Approximately three-quarters of patients who were non-smokers by virtue of being in a secure non-smoking environment commenced smoking after transfer. Monitoring of clozapine serum levels and assessment of mental state in the immediate period after a change in smoking status is indicated.
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Affiliation(s)
- Inti Qurashi
- High Secure Services, Ashworth High Secure Hospital, UK
| | | | | | - Simon Chu
- Department of Psychology, University of Central Lancashire, UK
| | - Richard Drake
- Division of Psychology and Mental Health, University of Manchester, UK
| | - Lewis Couchman
- Therapeutic Drug Monitoring, Analytical Services International, UK
| | - Robert Flanagan
- Toxicology, King's College Hospital NHS Foundation Trust, UK
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16
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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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17
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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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18
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Gene polymorphisms potentially related to the pharmacokinetics of clozapine: a systematic review. Int Clin Psychopharmacol 2016; 31:179-84. [PMID: 25563806 DOI: 10.1097/yic.0000000000000065] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Clozapine is currently the ultimate effective therapy for otherwise treatment-refractory schizophrenia. However, the drug is also associated with many adverse effects, some of them potentially fatal. Thus, there is an unmet need to predict clinical response to clozapine. As the pharmacokinetics of clozapine vary considerably between and within individuals, there may be an association between genetic polymorphisms and clozapine plasma concentration and consequently, clinical response. We have reviewed studies that have investigated the association between clozapine metabolic pathways related to genes polymorphisms in relation to plasma clozapine concentration and clinical response. Overall, most of the studies reported negative results. The only gene polymorphism that has been found to be associated with clozapine plasma concentration and response was the ABCB1 gene, which codes for transmembrane transporters expressed in the bowel mucosa, blood-brain barrier, kidney and liver. More prospective longitudinal studies are needed to elucidate the possible role of the ABCB1 polymorphism and transmembrane transporters in clozapine pharmacokinetics and clinical response.
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19
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Olsson E, Edman G, Bertilsson L, Hukic DS, Lavebratt C, Eriksson SV, Ösby U. Genetic and Clinical Factors Affecting Plasma Clozapine Concentration. Prim Care Companion CNS Disord 2015; 17:14m01704. [PMID: 26137357 DOI: 10.4088/pcc.14m01704] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/01/2014] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To assess (1) the variance of plasma clozapine levels; (2) the relative importance of sex, smoking habits, weight, age, and specific genetic variants of cytochrome P450 1A2 (CYP1A2), uridine diphosphate glucuronosyltransferase 1A4 (UGT1A4), and multidrug resistance protein 1 (MDR1) on plasma levels of clozapine; and (3) the relation between plasma clozapine levels, fasting glucose levels, and waist circumference. METHOD There were 113 patients on clozapine treatment recruited from psychosis outpatient clinics in Stockholm County, Sweden. Patients had genotype testing for single nucleotide polymorphisms: 2 in MDR1, 3 in CYP1A2, and 1 in UGT1A4. Multiple and logistic regression were used to analyze the relations. RESULTS There was a wide variation in plasma concentrations of clozapine (mean = 1,615 nmol/L, SD = 1,354 nmol/L), with 37% of the samples within therapeutic range (1,100-2,100 nmol/L). Smokers had significantly lower plasma clozapine concentrations than nonsmokers (P ≤ .03). There was a significant association between the rs762551 A allele of CYP1A2 and lower plasma clozapine concentration (P ≤ .05). Increased fasting glucose level was 3.7-fold more frequent in CC and CA genotypes than AA genotype (odds ratio = 0.27; 95% confidence interval, 0.10-0.72). There was no significant relation between higher fasting glucose levels, larger waist circumference, and higher clozapine levels. CONCLUSIONS It is difficult to predict plasma clozapine concentration, even when known individual and genetic factors are considered. Therefore, therapeutic drug monitoring is recommended in patients who are treated with clozapine.
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Affiliation(s)
- Eric Olsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Gunnar Edman
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Leif Bertilsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Dzana Sudic Hukic
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Catharina Lavebratt
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Sven V Eriksson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
| | - Urban Ösby
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, and Department of Adult Psychiatry, PRIMA Barn och Vuxenpsykiatri AB, Stockholm (Dr Olsson); Department of Psychiatry, Tiohundra AB, Norrtälje (Drs Edman and Ösby and Ms Hukic); Department of Neurobiology, Care Sciences and Society, Centre of Family Medicine, Karolinska Institutet, Stockholm (Drs Edman and Ösby); Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Drs Edman, Lavebratt, and Ösby); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm (Dr Bertilsson); Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm (Drs Hukic and Lavebratt); and Department of Cardiology, Danderyd University Hospital, Karolinska Institutet, Stockholm (Dr Eriksson), Sweden
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Population pharmacokinetic/pharmacodynamic model of clozapine for characterizing the relationship between accumulated exposure and PANSS scores in patients with schizophrenia. Ther Drug Monit 2015; 36:378-86. [PMID: 24342896 DOI: 10.1097/ftd.0000000000000014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The aim of this study was to characterize the relationship between accumulated exposure of clozapine and changes in Positive and Negative Syndrome Scale (PANSS) score in Chinese patients with schizophrenia by pharmacokinetic/pharmacodynamic (PK/PD) modeling. METHODS Sparse clozapine PK data and PANSS scores were collected from 2 clinical studies of Chinese inpatients with schizophrenia. Two other rich PK data sets were included for more accurate assessment of clozapine PK characteristics. The relationship between clozapine-accumulated exposure and PANSS score was investigated using linear, log-linear, E(max), and sigmoid models, and each model was evaluated using visual predictive condition and normalized prediction distribution error methods. Simulations based on the final PK/PD model were preformed to investigate the effect of clozapine on PANSS scores under different dose regimens. RESULTS A total of 1391 blood clozapine concentrations from 198 subjects (180 patients and 18 healthy volunteers) and 576 PANSS scores from 137 patients were included for PK and PK/PD analysis. A first-order 2-compartment PK model with covariates gender and smoking status influencing systemic clearance adequately described the PK profile of clozapine. The decrease in total PANSS score during treatment was best characterized using cumulated clozapine area under the curve (AUC) data in the E(max) model. The maximum decrease in PANSS during clozapine treatment (Emax) was 55.4%, and the cumulated AUC(50) (cAUC(50)) required to attain half of E(max) was 296 mg·L(-1)·h(-1)·d(-1). The simulations demonstrated that the accelerated dose titration and constant dose regimens achieved a similar maximum drug response but with a slower relief of symptoms in dose titration regimen. CONCLUSIONS The PK/PD model can describe the clinical response as measured by decreasing PANSS score during treatment and may be useful for optimizing the dose regimen for individual patients.
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Adverse Effects of Clozapine in Older Patients: Epidemiology, Prevention and Management. Drugs Aging 2013; 31:11-20. [DOI: 10.1007/s40266-013-0144-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Guenette MD, Powell V, Johnston K, Foussias G, Agid O, Hahn M, Takeuchi H, Remington G. Risk of neutropenia in a clozapine-treated elderly population. Schizophr Res 2013; 148:183-5. [PMID: 23727216 DOI: 10.1016/j.schres.2013.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/30/2013] [Accepted: 05/02/2013] [Indexed: 10/26/2022]
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