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de Leon J, Ruan CJ, Schoretsanitis G, Villasante-Tezanos AG, Spina E, Sanz EJ, Betancort M, De Las Cuevas C. Investigating in VigiBase over 6000 cases of pneumonia in clozapine-treated patients in the context of the literature: focus on high lethality and the association with aspiration pneumonia. Expert Opin Drug Metab Toxicol 2024:1-15. [PMID: 38920369 DOI: 10.1080/17425255.2024.2373111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND The literature associates clozapine with pneumonia/aspiration pneumonia. RESEARCH DESIGN AND METHODS The international pharmacovigilance database (VigiBase™) uses the information component (IC) as statistical signal. VigiBase clozapine reports were analyzed for pneumonia/aspiration pneumonia from introduction to 10 May 2023. RESULTS There were 6392 cases of all types of pneumonia (5572 cases of pneumonia, 775 of aspiration pneumonia, and 45 combined). The IC was 3.52 for aspiration pneumonia, introduced as a VigiBase label in 2003, and 1.91 for pneumonia. Patients were reclassified as 3628 with no signs of aspiration and 1533 with signs. Signs of aspiration were strongly associated with some co-medications: olanzapine, odds ratio (OR) = 23.8, 95% confidence interval (CI), 14.9-38.0; risperidone OR = 18.6, CI, 11.4-30.4; valproic acid, OR = 5.5, CI, 4.5-6.6; and benzodiazepines OR = 5.5, CI, 4.5-6.6. In 2415 cases with completed data, fatal outcomes made up 45% (signs of aspiration made no difference), but there was wide variability from 0% (females <45 years of age; duration ≤30 days) to 76% (males >64 years of age; duration >1 year). During the first week, pneumonia was associated with 1) very high titration doses, 2) very small doses in Parkinson's disease, and 3) Japan vs other countries. CONCLUSIONS In clozapine-treated patients: 1) at least 30% of pneumonia cases may be aspiration pneumonia, 2) stopping some co-medications may decrease the risk of aspiration pneumonia, 3) average lethality in pneumonia was 45% but may be around 75% in geriatric patients with long-term treatment, and 4) safer titrations may sometimes require 5-mg tablets.
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Affiliation(s)
- 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
| | - Can-Jun Ruan
- Laboratory of Clinical Psychopharmacology, Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
- The National Clinical Research Centre for Mental Disorders & Beijing Key Lab of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - 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, NY, USA
- Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA
| | | | - Edoardo Spina
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Emilio J Sanz
- Department of Physical Medicine and Pharmacology, School of Medicine, Universidad de La Laguna, La Laguna, Canary Islands, Spain
| | - Moisés Betancort
- Department of Clinical Psychology, Psychobiology, and Methodology, Universidad de La Laguna, La Laguna, Canary Islands, Spain
| | - Carlos De Las Cuevas
- Department of Internal Medicine, Dermatology and Psychiatry and Instituto Universitario de Neurociencia (IUNE), Universidad de La Laguna, La Laguna, Canary Islands, Spain
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Albitar O, Harun SN, Sheikh Ghadzi SM. Semi-physiological Pharmacokinetic Model of Clozapine and Norclozapine in Healthy, Non-smoking Volunteers: The Impact of Race and Genetics. CNS Drugs 2024; 38:571-581. [PMID: 38836990 DOI: 10.1007/s40263-024-01092-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/17/2024] [Indexed: 06/06/2024]
Abstract
BACKGROUND AND OBJECTIVES: Clozapine is the medication of choice for treatment-resistant schizophrenia. However, it has a complex metabolism and unexplained interindividual variability. The current work aims to develop a pharmacokinetic model of clozapine and norclozapine in non-smokers and assess the impact of demographic and genetic predictors. METHODS Healthy volunteers were recruited in a population pharmacokinetic study. Blood samples were collected at 30 min and 1, 2, 3, 5 and 8 h following a single flat dose of clozapine (12.5 mg). The clozapine and norclozapine concentrations were measured via high-performance liquid chromatography-ultraviolet method. A semi-physiological pharmacokinetic model of clozapine and norclozapine was developed using nonlinear mixed-effects modeling. Clinical and genetic predictors were evaluated, including CYP1A2 (rs762551) and ABCB1 (rs2032582), using restriction fragment length polymorphism. RESULTS A total of 270 samples were collected from 33 participants. The data were best described using a two-compartment model for clozapine and a two-compartment model for norclozapine with first-order absorption and elimination and pre-systemic metabolism. The estimated (relative standard error) clearance of clozapine and norclozapine were 27 L h-1 (31.5 %) and 19.6 L h-1 (30%), respectively. Clozapine clearance was lower in sub-Saharan Africans (n = 4) and higher in Caucasians (n = 9) than Asians (n = 20). Participants with CYP1A2 (rs762551) (n = 18) and ABCB1 (rs2032582) (n = 12) mutant alleles had lower clozapine clearance in the univariate analysis. CONCLUSIONS This is the first study to develop a semi-physiological pharmacokinetic model of clozapine and norclozapine accounting for the pre-systemic metabolism. Asians required lower doses of clozapine as compared with Caucasians, while clozapine pharmacokinetics in sub-Saharan Africans should be further investigated in larger trials.
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Affiliation(s)
- Orwa Albitar
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, USM, 11800, Gelugor, Penang, Malaysia
- Roche Pharma Research and Early Development, Basel, Switzerland
| | - Sabariah Noor Harun
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, USM, 11800, Gelugor, Penang, Malaysia
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Baptista T, Motuca M, Serrano A, Perez Lo Presti A, Fernandez-Arana A, Olmos I, Pabon A, Yepez JGA, Alejo Galarza GDJ, Rivera Ramirez NM, Elkis H, Sanz EJ, De Las Cuevas C, de Leon J. An expert review of clozapine in Latin American countries: Use, monitoring, and pharmacovigilance. Schizophr Res 2024; 268:60-65. [PMID: 37985318 DOI: 10.1016/j.schres.2023.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/22/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
There is growing interest in clozapine clinical use, monitoring, and research, particularly adverse drug reactions (ADRs) other than agranulocytosis. In this study we focused on clozapine pharmacovigilance. Hence, we contacted clinicians and researchers in Latin America and requested information about local psychiatric services, clozapine availability, clinical use, and ADR monitoring with the VigiBase system. Only two countries have the minimum recommended number of psychiatric beds (15 per 100,000 residents): Uruguay (N = 34.9) and Argentina (N = 17). Bolivia is the only country where clozapine is unavailable. Nine out of twenty countries (45 %) reported ADRs to VigiBase. Argentina, Brazil, Chile, Colombia, and Mexico published national guidelines for schizophrenia treatment. Chile is the sole country with clozapine clinics with drug serum monitoring. Ethnicity-related drug titration in not described in package inserts in any country. We examined in detail the 9 most frequent and important clozapine ADRs in the worldwide database (pneumonia, sudden death, cardiac arrest, agranulocytosis, myocarditis, constipation, arrhythmia, seizure, and syncope). These 9 ADRs led to 294 reports with fatal outcomes in Argentina (N = 3), Brazil (N = 3), Chile (N = 2), and Peru (N = 1). Agranulocytosis was reported from 7 countries: constipation or seizures from 8 countries. Only two countries reported pneumonia and one country reported myocarditis. The number of clozapine reports in VigiBase has no relationship to the country's population. All Latin American countries underreport clozapine associated ADRs. Latin American governments, along with clinicians, researchers, and educators, should optimize clozapine use and monitoring for the benefit of people with severe mental and some neurological disorders.
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Affiliation(s)
- Trino Baptista
- Department of Physiology, Los Andes University Medical School, Mérida, Venezuela; Medical School, Anáhuac University, Querétaro, Mexico; Neuroorigen, Querétaro, Mexico.
| | - Mariano Motuca
- Department of Psychiatry, School of Medicine at Universidad Nacional de Cuyo, Mendoza, Argentina; Instituto Vilapriño, Centro de Estudios, Asistencia e Investigación en Neurociencias, Mendoza, Argentina
| | - Ana Serrano
- SAMEIN, Salud Mental Integral SAS, Medellin, Colombia
| | | | | | - Ismael Olmos
- Clinical Pharmacology Unit and Pharmacy Department, Vilardebó Hospital, Administración de Servicios de Salud, Montevideo, Uruguay; Clinical Pharmacology Unit and Outpatient Clinic, Vilardebó Hospital, Administración de Servicios de Salud, Montevideo, Uruguay
| | - Albis Pabon
- Los Andes University Hospital, Psychiatric Unit, Merida, Venezuela
| | - Juan Genaro Ayala Yepez
- Posgrado de Psiquiatría, Facultad de Ciencias Médicas de la Universidad Central del Ecuador, Quito, Ecuador; Centro Ambulatorio especializado San Lázaro, Ministerio de Salud Pública, Quito, Ecuador
| | | | | | - Helio Elkis
- Department and Institute of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil
| | - Emilio J Sanz
- Department of Physical Medicine and Pharmacology, School of Medicine, Universidad de La Laguna, Canary Islands, Spain; Hospital Universitario de Canarias, Tenerife, Spain
| | - 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 at Eastern State Hospital, Lexington, KY, USA; Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apostol Hospital, University of the Basque Country, Vitoria, Spain
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Verdoux H, Quiles C, de Leon J. Optimizing antidepressant and clozapine co-prescription in clinical practice: A systematic review and expert recommendations. Schizophr Res 2024; 268:243-251. [PMID: 37852856 DOI: 10.1016/j.schres.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023]
Abstract
OBJECTIVES To synthesize the information relevant for clinical practice on clozapine-antidepressant co-prescription concerning pharmacokinetic drug-drug interactions (DDI), adverse drug reactions (ADRs) associated with the co-prescription, antidepressant add-on for clozapine-resistant symptoms and antidepressant add-on for clozapine-induced ADRs. METHODS Articles were identified with MEDLINE, Web of Sciences and PsycINFO search from inception through April 2023. Data were synthesized narratively. RESULTS ADRs are most often induced by the co-prescription of antidepressants that inhibit CYP enzymes (fluvoxamine, fluoxetine, paroxetine). Fluvoxamine add-on is hazardous because of its potent inhibition of clozapine metabolism and has few indications (lowering daily number of clozapine tablets, reducing norclozapine-induced metabolic disturbances and other dose-dependent clozapine-induced ADRs). ADR frequency may be reduced by therapeutic drug monitoring and knowledge of other factors impacting clozapine metabolism (pneumonia, inflammation, smoking, etc.). Improvement of negative symptoms is the most documented beneficial effect of antidepressant add-on for clozapine-resistant psychotic symptoms. The add-on antidepressant should be chosen according to its safety profile regarding DDI with clozapine: antidepressants inhibiting clozapine metabolism or increasing the anticholinergic load should be avoided. Other indications of antidepressant add-on (affective or obsessive compulsive symptoms, sialorrhea, and enuresis) are poorly documented. CONCLUSION Antidepressant add-on to clozapine is associated with potential benefits in clozapine users as this strategy may contribute to reduce the burden of clozapine-resistant symptoms or of clozapine-induced ADRs. Further studies are needed to determine whether antidepressant add-on can reduce the risk of clozapine discontinuation.
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Affiliation(s)
- Hélène Verdoux
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team Pharmacoepidemiology, UMR 1219, F-33000 Bordeaux, France.
| | - Clélia Quiles
- Centre Hospitalier Charles Perrens, F-33000 Bordeaux, France
| | - Jose de Leon
- Mental Health Research Center at Eastern State Hospital, Lexington, KY, Psychiatry and Neurosciences Research Group (CTS-549), USA; 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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Leung JG, Allen ND, Markota M. A case series of clozapine titrations affected by inflammatory processes. Schizophr Res 2024; 268:94-97. [PMID: 37633777 DOI: 10.1016/j.schres.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/28/2023]
Affiliation(s)
- Jonathan G Leung
- Department of Pharmacy, Mayo Clinic Rochester, MN, United States of America.
| | - Nicholas D Allen
- Department of Psychiatry and Psychology, Mayo Clinic Rochester, MN, United States of America
| | - Matej Markota
- Department of Psychiatry and Psychology, Mayo Clinic Rochester, MN, United States of America
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Baptista T, Serrano A, Presti APL, Fernandez-Arana A, Elkis H, Motuca M, Olmos I, Schoretsanitis G. Clozapine safety monitoring and related research in psychiatry and neurology in South America: A scoping review. Schizophr Res 2024; 268:29-33. [PMID: 37541864 DOI: 10.1016/j.schres.2023.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/20/2023] [Accepted: 07/21/2023] [Indexed: 08/06/2023]
Abstract
The quality and quantity of clozapine safety monitoring considerably differs among South American countries and mainly focus on hematological surveillance. Few studies have been conducted on other clozapine-related adverse effects (ADRs) and mainly refer to case reports and literature reviews. We retrieved thirty-nine publications on clozapine related ADRs others than neutropenia. Studies in Brazil and Venezuela accounted for 67 % of all the publications, and 8 out of 12 countries published 2 or less manuscripts. Only Chile offers serum clozapine level measurement in public institutions. Given the recently recognized role of ethnicity, gender, smoking, obesity drug interactions in optimal clozapine administration, modernization of clozapine clinical use and research in psychiatry and neurology most be broadcasted and stimulated in South American countries.
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Affiliation(s)
- Trino Baptista
- Department of Physiology, Los Andes University Medical School, Mérida, Venezuela; Medical School, Anáhuac University, Querétaro, Mexico; Neuroorigen, Querétaro, Mexico.
| | - Ana Serrano
- SAMEIN, Salud Mental Integral SAS, Medellin, Colombia.
| | | | | | - Helio Elkis
- Department and Institute of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil.
| | - Mariano Motuca
- Department of Psychiatry, School of Medicine at Universidad Nacional de Cuyo, Mendoza, Argentina; Instituto Vilapriño, Centro de Estudios, Asistencia e Investigación en Neurociencias, Mendoza, Argentina.
| | - Ismael Olmos
- Clinical Pharmacology Unit and Pharmacy Department, Vilardebó Hospital, Administración de Servicios de Salud, Montevideo, Uruguay; 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, NY, USA; Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA.
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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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Kikuchi Y, Komatsu H, Otsuka Y, Ito F, Kanahara N, Tanifuji H, Tomita H. Slower clozapine titration than the official Japanese protocol led to fewer inflammatory adverse effects: A retrospective chart review of seven hospitals. Schizophr Res 2024; 268:98-106. [PMID: 37331881 DOI: 10.1016/j.schres.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/20/2023]
Abstract
BACKGROUND Higher frequencies of inflammatory adverse effects of clozapine have been reported in Japan. As the international titration protocol for Asians has set slower dose titration than the Japanese package insert, we hypothesized that a dose titration speed slower than the recommendation of the guideline would be associated with fewer inflammatory-related adverse events. METHODS The medical records of all 272 patients who were first started on clozapine at seven hospitals between 2009 and 2023 were studied retrospectively. Of those, 241 were included in the analysis. The patients were divided into two groups regarding whether the titration speed was faster or slower than the guideline for Asians. The incidence of inflammatory adverse events with clozapine was compared between the groups. RESULTS The frequency of inflammatory adverse events was 34 % (37/110) in the faster titration group and 13 % (17/131) in the slower titration group, and a significant difference was observed by Fisher exact test (odds ratio 3.38; 95 % confidence interval 1.71-6.91; p < 0.001). Serious adverse effects, fever for more than five days, and clozapine discontinuation were significantly more frequent in the faster titration group. Logistic regression analysis indicated significantly more inflammatory adverse events in the faster titration group (adjusted odds ratio 4.01; 95 % confidence interval 2.02-7.87; p < 0.001) considering age, sex, body mass index, concomitant valproic acid, and smoking as confounding factors. CONCLUSION Clozapine-induced inflammatory adverse events were less frequent in Japanese individuals when a titration rate was more gradual than the protocol recommended in the Japanese package insert.
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Affiliation(s)
- Yuki Kikuchi
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan; Department of Psychiatry, Kodama Hospital, Ishinomaki, Miyagi, Japan.
| | - Hiroshi Komatsu
- Department of Psychiatry, Tohoku University Hospital, Sendai, Miyagi, Japan
| | - Yuji Otsuka
- Department of Psychiatry, Asahi General Hospital, Asahi, Japan.
| | - Fumiaki Ito
- National Hospital Organization Hanamaki Hospital, Hanamaki, Japan
| | - Nobuhisa Kanahara
- Department of Psychiatry, Chiba University Graduate School of Medicine, Chiba, Japan; Division of Medical Treatment and Rehabilitation, Center for Forensic Mental Health, Chiba University, Chiba, Japan.
| | - Hiroaki Tanifuji
- Department of Pharmacy, Kodama Hospital, Ishinomaki, Miyagi, Japan.
| | - Hiroaki Tomita
- Department of Psychiatry, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan; Department of Psychiatry, Tohoku University Hospital, Sendai, Miyagi, Japan.
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9
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De Las Cuevas C, Sanz EJ, de Leon J. Adverse drug reactions and their fatal outcomes in clozapine patients in VigiBase: Comparing the top four reporting countries (US, UK, Canada and Australia). Schizophr Res 2024; 268:165-174. [PMID: 37301669 DOI: 10.1016/j.schres.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pharmacovigilance findings and box warnings in the clozapine package inserts have marked the history of clozapine. OBJECTIVE This is the largest review of clozapine adverse drug reactions (ADRs) and their associated fatal outcomes. Reports to the World Health Organization's global pharmacovigilance database, VigiBase™, were analyzed, extending from clozapine's introduction to December 31, 2022. METHODS The analysis focused on the top four reporting countries: United States (US), United Kingdom (UK), Canada and Australia (83 % of fatal outcomes worldwide). Attempts were made to control for population and clozapine prescription in each country. RESULTS Clozapine ADRs worldwide accounted for 191,557 reports, with the highest number (53,505) in "blood and lymphatic system disorder". Of the 22,596 fatal outcomes reported in clozapine patients, 9587 were from the US, 6567 from the UK, 3623 from Canada and 1484 from Australia. The top category worldwide in fatal outcomes was nonspecifically labeled "death" with 46 % (range 22-62 %). "Pneumonia" was second with 30 % (range 17-45 %). Agranulocytosis was numerically only the 35th top clozapine ADR associated with fatal outcomes. On average, 2.3 clozapine ADRs were reported per fatal outcome. Infections were associated with 24.2 % of the UK fatal outcomes (9.4 %-11.9 % in the 3 other countries). CONCLUSIONS The four countries appeared to report clozapine ADRs in different ways, making comparisons difficult. We estimated higher fatal outcomes in the UK and Canada after controlling for cross-sectional estimations of population and published clozapine use. This last hypothesis is limited by the lack of precise estimation of accumulated clozapine use in each country.
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Affiliation(s)
- 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.
| | - Emilio J Sanz
- Department of Physical Medicine and Pharmacology, School of Medicine, Universidad de La Laguna, Canary Islands, Spain; Hospital Universitario de Canarias, Tenerife, Spain
| | - Jose de Leon
- Mental Health Research Center at Eastern State Hospital, Lexington, KY, USA; Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apostol Hospital, University of the Basque Country, Vitoria, Spain.
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de Leon J, Wang L, Simpson GM. The introduction of clozapine at the Nathan Kline Institute in New York and its long-term consequences. Schizophr Res 2024; 268:14-20. [PMID: 37689508 DOI: 10.1016/j.schres.2023.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 09/11/2023]
Abstract
Nathan S. Kline was a pioneer in psychopharmacology in the United States (US). In 1952, Kline started a research unit at Rockland State Hospital, New York. Kline brought clozapine from Switzerland since it was not yet available in the US. At Rockland State Hospital, George Simpson had conducted antipsychotic trials and had developed scales to assess movement disorders. In 1974, Simpson published the first US clozapine trial. In 1978, he published on 1) the effect of clozapine on tardive dyskinesia and 2) high plasma clozapine concentrations in two patients with seizures. His experience of clozapine withdrawal symptoms in his first 2 trials led in the future to more articles in this area. In Philadelphia, Simpson designed a double-blind randomized clinical trial (RCT) with 3 doses (100, 300 and 600 mg/day) which was published in 1999. From the 50 patients started on the RCT, 47 provided repeated plasma clozapine concentrations every other week of the RCT. This rich database of plasma clozapine concentrations under controlled conditions has contributed to many of the advances in clozapine pharmacokinetics in the last 5 years including: 1) obesity can be associated with clozapine poor metabolism (PM) status, 2) a clozapine ultrarapid metabolizer (UM) with a minimum therapeutic dose of 1591 mg/day, 3) a case of clozapine intoxication dropped from the RCT due to pneumonia, 4) cases of increased plasma concentrations during clozapine-induced fever, 5) the possibility that African-Americans may need higher clozapine doses than those of European ancestry, and 6) three indices of non-adherence.
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Affiliation(s)
- 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.
| | - Linda Wang
- Department of Psychiatry, University of Southern California, Los Angeles, CA, United States of America
| | - George M Simpson
- Department of Psychiatry, University of Southern California, Los Angeles, CA, United States of America.
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Kirilochev O, Chumakov E, Kuzo N, Schoretsanitis G. A scoping review of literature on clozapine from former USSR states published in Russian language. Schizophr Res 2024; 268:38-47. [PMID: 37741739 DOI: 10.1016/j.schres.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/25/2023]
Abstract
OBJECTIVE Access to literature on clozapine in Russian language remains strikingly limited. We aimed to identify and translate clinical evidence on clozapine-based treatment outcomes. METHODS We performed a systematic review in PubMed, Embase and scientific indexes from former USSR states searching for articles published in Russian from the database inception till January 2023 and summarized the data in a scoping review (PROSPERO Reg. Number CRD42023386737). RESULTS A total of 60 papers were included comprising eight main topic categories: 1) clozapine-related intoxications (n = 20), 2) effectiveness/efficacy and safety of clozapine treatment (n = 14), 3) adverse drug-induced reactions (ADRs) related to clozapine treatment (n = 9), 4) therapeutic drug monitoring for clozapine (n = 5), 5) combination of clozapine and non-pharmacological treatments (n = 4), 6) pharmacoepidemiology of clozapine (n = 3), 7) effects of clozapine on the brain electrical activity (n = 3), and 8) novel clozapine formulations (n = 2). Among clozapine-related intoxications there were reports of criminal poisoning, which was associated with low lethality. Worse outcomes were accompanied by systemic reactions to intoxications. Clinical benefits of hemoadsorption were reported in the management of clozapine-related intoxications. Only half of studies reporting clozapine effectiveness used standardized scales to assess outcomes. Clozapine superiority in treatment-resistant schizophrenia (TRS) was replicated in one trial. No reports of clozapine-related agranulocytosis were identified. Clozapine ranked among most prescribed antipsychotics for TRS and non-TRS. CONCLUSIONS As clinical research in former USSR states is advancing to adopt western clinical research standards, comparability and extrapolation of findings is expected to increase, with transfer of older findings to clinical practice being particularly challenging.
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Affiliation(s)
- Oleg Kirilochev
- Department of Clinical Pharmacology, Astrakhan State Medical University, Astrakhan, Russian Federation.
| | - Egor Chumakov
- Department of Psychiatry and Addiction, Saint-Petersburg State University, Saint-Petersburg, Russian Federation
| | - Nazar Kuzo
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatry University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Georgios Schoretsanitis
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatry University Hospital Zurich, University of Zurich, Zurich, Switzerland; Department of Psychiatry, The Zucker Hillside Hospital, Northwell Health, Glen Oaks, NY, USA; Department of Psychiatry and Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
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de Leon J. Can Slow Personalized Titration Using C-Reactive Protein Monitoring Decrease the High Rates and Mortality of Clozapine-Associated Myocarditis Seen in Some Countries? A Call for Research. J Clin Psychopharmacol 2024; 44:212-219. [PMID: 38595145 DOI: 10.1097/jcp.0000000000001843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
PURPOSE/BACKGROUND The hypothesis that slower personalized titration may prevent clozapine-associated myocarditis and decrease the disproportion incidence of 3% found in Australia was not described in a recent Australian article in this journal. METHODS Six countries in addition to Australia have published information suggesting a similar incidence of clozapine-associated myocarditis. On September 19, 2023, PubMed searches were updated for articles from the United States, Korea, Japan, Canada, New Zealand, and Turkey. FINDINGS/RESULTS An incidence of 3.5% (4/76) was found in a US hospital, but US experts were the first to propose that clozapine-associated myocarditis may be a hypersensitivity reaction associated with rapid titration and possibly preventable. Koreans and Japanese are of Asian ancestry and need lower minimum therapeutic doses for clozapine than patients of European ancestry. A 0.1% (2/1408) incidence of myocarditis during clozapine titration was found in a Korean hospital, but pneumonia incidence was 3.7% (52/1408). In 7 Japanese hospitals, 34% (37/110) of cases of clozapine-associated inflammation were found during faster titrations (based on the official Japanese titration) versus 13% (17/131) during slower titrations (based on the international titration guideline for average Asian patients). Recent limited studies from Canada, New Zealand, and Turkey suggest that slower personalized titration considering ancestry may help prevent clozapine-associated myocarditis. IMPLICATIONS/CONCLUSIONS Other countries have very limited published data on clozapine-associated myocarditis. Based on a recent Australian case series and these non-Australian studies, the author proposes that Australia (and other countries) should use slow personalized titration for clozapine based on ancestry and c-reactive protein monitoring.
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Jiménez-Fernández S, Gurpegui M, Correll CU, de Leon J, Schoretsanitis G. A Systematic Review of Clozapine Concentration-Dose Ratio from Therapeutic Drug Monitoring Studies in Children and Adolescents Treated with Clozapine for Mental Disorders. Ther Drug Monit 2024; 46:170-180. [PMID: 38018845 PMCID: PMC10930379 DOI: 10.1097/ftd.0000000000001154] [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: 07/31/2023] [Accepted: 09/14/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND Therapeutic drug monitoring of clozapine in children and adolescents has received insufficient attention. Calculation of concentration-to-dose (C/D) ratios from trough steady-state concentrations estimate drug clearance. METHODS A systematic electronic literature search was conducted in 3 article databases from inception until January 10, 2023, and articles reporting clozapine concentrations in children and adolescents were retrieved. The pharmacokinetic quality of the studies was assessed, and clozapine C/D ratios were calculated using the sample mean clozapine dose and concentration. RESULTS Of the 37 articles of potential interest, only 7 reported clozapine trough and steady-state concentrations. After excluding case reports and a study confounded by fluvoxamine, 4 studies on psychosis from Europe and the United States were included. The clozapine C/D ratios were similar to published adult values and ranged from 0.82 to 1.24 with a weighted mean of 1.08 ng/mL per mg/d. The weighted means were 334 mg/d for the dose and 380 ng/mL for the concentration. The stratified analysis of the weighted mean clozapine C/D ratios from 2 studies showed lower values in 52 male (1.05 ng/mL per mg/d) than in 46 female (1.46 ng/mL per mg/d) children and adolescents, with values similar to those reported for European adult nonsmokers. Two female adolescents had high clozapine C/D ratios (2.54 ng/mL per mg/d), an Asian American patient with borderline obesity and a patient with intellectual disability with low dosage (mean = 102 mg/d) and concentration (mean = 55 ng/mL). CONCLUSIONS Reports on clozapine therapeutic drug monitoring in children and adolescents are limited in number and quality. Future studies should focus on basic pharmacokinetic issues, such as stratification by sex, smoking, and relevant comedications with inductive or inhibitory properties.
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Affiliation(s)
- Sara Jiménez-Fernández
- Child and Adolescent Mental Health Unit, Virgen de Las Nieves University Hospital, Granada, Spain
- CTS-549 Research Group (Psychiatry and Neurosciences), Junta de Andalucía, Spain
| | - Manuel Gurpegui
- CTS-549 Research Group (Psychiatry and Neurosciences), Junta de Andalucía, Spain
- Granada Center for Psychiatric Studies, Granada, Spain
| | - Christoph U. Correll
- Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany
- The Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, New York
- Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, New York
| | - Jose de Leon
- Mental Health Research Center, Eastern State Hospital, Lexington, Kentucky
- Biomedical Research Centre in Mental Health Net (CIBERSAM), Santiago Apóstol Hospital, University of the Basque Country, Vitoria, Spain; and
| | - Georgios Schoretsanitis
- The Zucker Hillside Hospital, Psychiatry Research, Northwell Health, Glen Oaks, New York
- Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, New York
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland
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Kingston E, Tingle M, Bellissima BL, Helsby N, Burns K. CYP-catalysed cycling of clozapine and clozapine- N-oxide promotes the generation of reactive oxygen species in vitro. Xenobiotica 2024; 54:26-37. [PMID: 38108307 DOI: 10.1080/00498254.2023.2294473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
Clozapine is an effective atypical antipsychotic indicated for treatment-resistant schizophrenia, but is under-prescribed due to the risk of severe adverse drug reactions such as myocarditis.A mechanistic understanding of clozapine cardiotoxicity remains elusive.This study aimed to investigate the contribution of selected CYP isoforms to cycling between clozapine and its major circulating metabolites, N-desmethylclozapine and clozapine-N-oxide, with the potential for reactive species production.CYP supersome™-based in vitro techniques were utilised to quantify specific enzyme activity associated with clozapine, clozapine-N-oxide and N-desmethylclozapine metabolism.The formation of reactive species within each incubation were quantified, and known intermediates detected.CYP3A4 predominately catalysed clozapine-N-oxide formation from clozapine and was associated with concentration-dependent reactive species production, whereas isoforms favouring the N-desmethylclozapine pathway (CYP2C19 and CYP1A2) did not produce reactive species.Extrahepatic isoforms CYP2J2 and CYP1B1 were also associated with the formation of clozapine-N-oxide and N-desmethylclozapine but did not favour one metabolic pathway over another.Unique to this investigation is that various CYP isoforms catalyse clozapine-N-oxide reduction to clozapine.This process was associated with the concentration-dependent formation of reactive species with CYP3A4, CYP1B1 and CYP1A1 that did not correlate with known reactive intermediates, implicating metabolite cycling and reactive oxygen species in the mechanism of clozapine-induced toxicity.
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Affiliation(s)
- Ellen Kingston
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Malcolm Tingle
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Brandi L Bellissima
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Nuala Helsby
- Department of Molecular Medicine and Pathology, The University of Auckland, Auckland, New Zealand
| | - Kathryn Burns
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
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Lock SK, Legge SE, Kappel DB, Willcocks IR, Helthuis M, Jansen J, Walters JTR, Owen MJ, O'Donovan MC, Pardiñas AF. Mediation and longitudinal analysis to interpret the association between clozapine pharmacokinetics, pharmacogenomics, and absolute neutrophil count. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2023; 9:74. [PMID: 37853043 PMCID: PMC10585000 DOI: 10.1038/s41537-023-00404-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
Clozapine is effective at reducing symptoms of treatment-resistant schizophrenia, but it can also induce several adverse outcomes including neutropenia and agranulocytosis. We used linear mixed-effect models and structural equation modelling to determine whether pharmacokinetic and genetic variables influence absolute neutrophil count in a longitudinal UK-based sample of clozapine users not currently experiencing neutropenia (N = 811). Increased daily clozapine dose was associated with elevated neutrophil count, amounting to a 133 cells/mm3 rise per standard deviation increase in clozapine dose. One-third of the total effect of clozapine dose was mediated by plasma clozapine and norclozapine levels, which themselves demonstrated opposing, independent associations with absolute neutrophil count. Finally, CYP1A2 pharmacogenomic activity score was associated with absolute neutrophil count, supporting lower neutrophil levels in CYP1A2 poor metabolisers during clozapine use. This information may facilitate identifying at-risk patients and then introducing preventative interventions or individualised pharmacovigilance procedures to help mitigate these adverse haematological reactions.
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Affiliation(s)
- Siobhan K Lock
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Sophie E Legge
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Djenifer B Kappel
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Isabella R Willcocks
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | | | - John Jansen
- Leyden Delta B.V., Nijmegen, The Netherlands
| | - James T R Walters
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Michael J Owen
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Michael C O'Donovan
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Antonio F Pardiñas
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK.
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de Leon J, De Las Cuevas C. Will ChatGPT3 Substitute for us as Clozapine Experts? J Clin Psychopharmacol 2023; 43:400-402. [PMID: 37683226 DOI: 10.1097/jcp.0000000000001734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
BACKGROUND ChatGPT3 is a new artificial intelligence program released on February 13, 2023. METHOD The authors tested ChatGPT3 on February 18, 2023, and repeated the test a week later. They used their expertise on the effects of ethnic ancestry in the stratification of clozapine dosing and the new idea that they published in March 2022 that African-Americans need higher clozapine doses because they have higher clozapine clearance. RESULTS In the first interaction on February 18, ChatGPT3 provided reasonable and very up-to-date information, which included a comment that patients of African ancestry have higher clozapine metabolism. The other 4 interactions became progressively more concerning as we asked ChatGPT3 to provide references to justify the latter statement. ChatGPT3 provided non-existent "references" using articles from real journals, with real authors, false PubMed identifiers, and false titles. Moreover, ChatGPT3 said that the first author wrote in 2003 that African-Americans had higher CYP1A2 activity when that did not happen until 2022. One week later, the second author repeated the same set of questions. This time ChatGPT3 described the opposite, that African-Americans have "lower" CYP1A2 activity and "slower" metabolism. ChatGPT3 provided another set of articles to justify the information; some were real but did not comment on clozapine metabolism in African-Americans while others did not exist. CONCLUSIONS ChatGPT3 provided a mixture of truth, twisted reality, and non-existent "facts." Within one week it defended opposite positions regarding a clinically relevant issue such as using higher or lower clozapine doses in African-Americans.
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Affiliation(s)
| | - Carlos De Las Cuevas
- Department of Internal Medicine, Dermatology and Psychiatry and Instituto Universitario de Neurociencia (IUNE), Universidad de La Laguna, La Laguna, Canary Islands, Spain
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17
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Flanagan RJ, Hunter S, Obee SJ. Assessing Adherence to Clozapine: Practical Considerations. J Clin Psychopharmacol 2023; 43:417-421. [PMID: 37683230 DOI: 10.1097/jcp.0000000000001736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
BACKGROUND The clinical assessment of adherence to clozapine may prove difficult. METHOD We studied the incidence of nonadherence (plasma clozapine <0.01 mg L -1 ) in samples submitted to a clozapine therapeutic drug monitoring (TDM) service, 1993-2017. RESULTS Clozapine was not detected in 2865 samples from men (2214 patients, 1.1% of all samples from men) and 1068 samples from women (822 patients, 1.0% of all samples from women). Information on the prescribed dose was supplied for 1623 of these samples from men and 492 of these samples from women. Prescribed doses ranged up to 1200 mg d -1 , although most were in the range 100 to 600 mg d -1 . Norclozapine was detected in 260 (9.1%) and 67 (6.3%) of the samples from men and from women, respectively, that did not contain clozapine. While an assay was requested to confirm either a patient history of nonadherence, or to establish that clozapine had been cleared from the circulation after overdosage, for example, in at least 38 instances, in the vast majority of cases the absence of clozapine from the sample was unexpected. IMPLICATIONS While adherence to clozapine may be good in general, tolerance to its potentially fatal cardiovascular effects is easily lost. Moreover, in treatment-resistant schizophrenia, the risk of self-harm increases if the drug is not taken regularly. In addition to presently available TDM services, the advent of a clozapine immunoassay for laboratory use should make it easy to institute at least monthly clozapine TDM at minimal extra cost.
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Affiliation(s)
- Robert J Flanagan
- From Precision Medicine, Networked Services, Bessemer Wing, King's College Hospital NHS Foundation Trust, London, United Kingdom
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