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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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Nuebel M, Leung JG, Hughes C, McGrane I. Evaluation of major adverse events of clozapine based on accordance to an international titration guideline. Ment Health Clin 2024; 14:204-211. [PMID: 38835819 PMCID: PMC11147652 DOI: 10.9740/mhc.2024.06.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 01/02/2024] [Indexed: 06/06/2024] Open
Abstract
Introduction Clozapine is the only antipsychotic approved for treatment-resistant schizophrenia, but without appropriate monitoring, it can be associated with potentially fatal outcomes. An International Adult Clozapine Titration Guideline categorizes patients into normal or slow metabolizers. Categorization provides clozapine titration schedules and recommends regular c-reactive protein (CRP) and clozapine concentration monitoring to reduce the risk of adverse drug reactions (ADRs). The impact of the guideline on clozapine ADRs has not been evaluated. Methods A retrospective chart review assessed clozapine titrations, laboratory monitoring, ADRs, and discontinuations for clozapine-naive adult inpatients at a single center from January 1, 2013, to June 1, 2022. Each patient's cumulative weekly clozapine dosage was compared with their guideline recommended dosage to create a percent accordance. Linear logistic regression evaluated the relationship between titration speed and the presence of an ADR, while descriptive statistics analyzed laboratory monitoring. Results Forty-three patients were included, with the majority being White males with schizophrenia. An inverse relationship existed between the last inpatient week clozapine dose percent accordance and the probability of an ADR. Nonobese patients were less likely than obese patients to experience an ADR (odds ratio = 0.17; 95% CI, 0.03-0.99). CRP and clozapine concentration monitoring was suboptimal. Discussion Based on our small retrospective review of primarily White males, more aggressive clozapine titrations did not increase ADRs. Future studies with more diverse samples are needed and should focus on specific ADRs, which may have increased occurrence with rapid titrations. Obese patients were at higher risk of ADRs, correlating with the guideline-recommended slower titrations for these patients.
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Affiliation(s)
- Matthew Nuebel
- (Corresponding author) Post Graduate Year One Pharmacy Resident, Department of Pharmacy, Providence St. Patrick Hospital, Missoula, Montana,
| | - Jonathan G. Leung
- Psychiatric Pharmacist, Department of Pharmacy, Mayo Clinic, Rochester, Minnesota
| | | | - Ian McGrane
- Associate Professor, Skaggs School of Pharmacy, University of Montana, Missoula, Montana
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Mansour K, Fredj NB, Ammar H, Romdhane HB, Mhalla A, Chaabane A, Chadli Z, Aouam K. Exploring clozapine pharmacokinetics in Tunisian schizophrenic patients: A population-based modelling approach investigating the impact of genetic and non-genetic variables. Basic Clin Pharmacol Toxicol 2024; 134:805-817. [PMID: 38599832 DOI: 10.1111/bcpt.14009] [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: 11/23/2023] [Revised: 02/29/2024] [Accepted: 03/22/2024] [Indexed: 04/12/2024]
Abstract
Clozapine is characterized by a large within- and between-patient variability in its pharmacokinetics, attributed to non-genetic and genetic factors. A cross-sectional analysis of clozapine trough concentration (Clz C0) issued from Tunisian schizophrenic patients was collected and analysed using a nonparametric modelling approach. We assessed the impact of demographic covariates (age, weight and sex), patient's habits (smoking status, alcohol and caffeine intake) and the genetic factors (CYP1A2*1C, CYP1A2*1F and CYP2C19*2 polymorphisms) on each pharmacokinetic parameter. An external validation of this pharmacokinetic model using an independent data set was performed. Fit goodness between observed- and individual-predicted data was evaluated using the mean prediction error (% MPE), the mean absolute prediction error (% MAPE) as a measure of bias, and the root mean squared error (% RMSE) as a measure of precision. Sixty-three CLz C0 values issued from 51 schizophrenic patients were assessed in this study and divided into building and validation groups. CYP1A2*1F polymorphism and smoking status were the only covariates significantly associated with clozapine clearance. Precision parameters were as follows: 1.02%, 0.95% and 22.4%, respectively, for % MPE, % MAPE and % RMSE. We developed and validated an accurate pharmacokinetic model able to predict Clz C0 in Tunisian schizophrenic patients using the two parameters CYP1A2*1F polymorphism and smoking.
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Affiliation(s)
- Khadija Mansour
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Nadia Ben Fredj
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Helmi Ammar
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Haifa Ben Romdhane
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Ahmed Mhalla
- Department of Psychiatry, Fattouma Bourguiba Hospital, Monastir, Tunisia
| | - Amel Chaabane
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Zohra Chadli
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
| | - Karim Aouam
- Department of Clinical Pharmacology, Fattouma Bourguiba Hospital, Faculty of Medicine, University of Monastir, Monastir, Tunisia
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Gronich N. Central Nervous System Medications: Pharmacokinetic and Pharmacodynamic Considerations for Older Adults. Drugs Aging 2024:10.1007/s40266-024-01117-w. [PMID: 38814377 DOI: 10.1007/s40266-024-01117-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2024] [Indexed: 05/31/2024]
Abstract
Most drugs have not been evaluated in the older population. Recognizing physiological alterations associated with changes in drug disposition and with the ultimate effect, especially in central nervous system-acting drugs, is fundamental. While considering pharmacokinetics, it should be noted that the absorption of most drugs from the gastrointestinal tract does not change in advanced age. There are only few data about the effect of age on the transdermal absorption of medications such as fentanyl. Absorption from an intramuscular injection may be similar in older adults as in younger patients. The distribution of lipophilic drugs (such as diazepam) is increased owing to a relative increase in the percentage of body fat, causing drug accumulation and prolonged drug elimination following cessation. Phase I drug biotransformation is variably decreased in aging, impacting elimination, and hepatic drug clearance has been shown to decrease in older individuals by 10-40% for most drugs studied. Lower doses of phenothiazines, butyrophenones, atypical antipsychotics, antidepressants (citalopram, mirtazapine, and tricyclic antidepressants), and benzodiazepines (such as diazepam) achieve the same extent of exposure. For renally cleared drugs with no prior metabolism (such as gabapentin), the glomerular filtration rate appropriately estimates drug clearance. Important pharmacodynamic changes in older adults include an increased sedative effect of benzodiazepines at a given drug exposure, and a higher sensitivity to mu opiate receptor agonists and to opioid adverse effects. Artificial intelligence, physiologically based pharmacokinetic modeling and simulation, and concentration-effect modeling enabling a differentiation between the pharmacokinetic and the pharmacodynamic effects of aging might help to close some of the gaps in knowledge.
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Affiliation(s)
- Naomi Gronich
- Department of Community Medicine and Epidemiology, Lady Davis Carmel Medical Center, Clalit Health Services, 7 Michal St, 3436212, Haifa, Israel.
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
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Berneri M, Jha U, O'Halloran S, Salman S, Wickramasinghe S, Kendrick K, Nguyen J, Joyce DA. Validation of Population Pharmacokinetic Models for Clozapine Dosage Prediction. Ther Drug Monit 2024; 46:217-226. [PMID: 38446630 DOI: 10.1097/ftd.0000000000001184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/03/2023] [Indexed: 03/08/2024]
Abstract
BACKGROUND Clozapine is unique in its capacity to ameliorate severe schizophrenia but at high risk of toxicity. A relationship between blood concentration and clinical response and evidence for concentration-response relationships to some adverse effects justify therapeutic drug monitoring of clozapine. However, the relationship between drug dose and blood concentration is quite variable. This variability is, in part, due to inductive and inhibitory interactions varying the activity of cytochrome P450 1A2 (CYP1A2), the principal pathway for clozapine elimination. Several population pharmacokinetic models have been presented to facilitate dose selection and to identify poor adherence in individual patients. These models have faced little testing for validity in independent populations or even for persisting validity in the source population. METHODS Therefore, we collected a large population of clozapine-treated patients (127 patients, 1048 timed plasma concentrations) in whom dosing and covariate information could be obtained with high certainty. A population pharmacokinetic model was constructed with data collected in the first 6 weeks from study enrolment (448 plasma concentrations), to estimate covariate influences and to allow alignment with previously published models. The model was tested for its performance in predicting the concentrations observed at later time intervals up to 5 years. The predictive performances of 6 published clozapine population models were then assessed in the entire population. RESULTS The population pharmacokinetic model based on the first 6 weeks identified significant influences of sex, smoking, and cotreatment with fluvoxamine on clozapine clearance. The model built from the first 6 weeks had acceptable predictive performance in the same patient population up to the first 26 weeks using individual parameters, with a median predictive error (PE) of -0.1% to -15.9% and median absolute PE of 22.9%-27.1%. Predictive performance fell progressively with time after 26 weeks. Bayesian addition of plasma concentration observations within each prediction period improved individual predictions. Three additional observations extended acceptable predictive performance into the second 6 months of therapy. When the published models were tested with the entire data set, median PE ranged from -8% to +35% with a median absolute PE of >39% in all models. Thus, none of the tested models was successful in external validation. Bayesian addition of single patient observations improved individual predictions from all models but still without achieving acceptable performances. CONCLUSIONS We conclude that the relationship between covariates and blood clozapine concentrations differs between populations and that relationships are not stable over time within a population. Current population models for clozapine are not capturing influential covariates.
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Affiliation(s)
- Massimo Berneri
- Schools of Medicine & Biomedical Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Uma Jha
- Schools of Medicine & Biomedical Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Seán O'Halloran
- Clinical Pharmacology & Toxicology, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| | - Sam Salman
- Clinical Pharmacology & Toxicology, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
- Medical School, University of Western Australia, Crawley, Western Australia, Australia
| | | | - Kevin Kendrick
- Fremantle Hospital Mental Health Service, Fremantle, Western Australia, Australia
| | - Jessica Nguyen
- Department of Pharmacy, Graylands Hospital, Mount Claremont, Western Australia, Australia ; and
| | - David A Joyce
- Schools of Medicine & Biomedical Sciences, University of Western Australia, Crawley, Western Australia, Australia
- Clinical Pharmacology & Toxicology, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
- Department of Clinical Pharmacology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
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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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Wu Y, Zhou Z, Ai Z, Wang T, Cui L. Abnormal blood concentration changes in a 71-year-old female who survived a 10,000mg overdose of clozapine: a case report. BMC Psychiatry 2024; 24:123. [PMID: 38355481 PMCID: PMC10865518 DOI: 10.1186/s12888-024-05582-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/03/2024] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Clozapine is a highly effective second-generation antipsychotic with few extrapyramidal reactions, making it a preferred choice among clinicians. However, instances of acute clozapine poisoning resulting from suicide attempts and misuse have been reported. Through our review of existing literature, we identified that we believe to be the highest recorded overdose of clozapine in elderly patients, resulting in a nonfatal outcome. CASE PRESENTATION The case report involves a 71-year-old female with a history of depression who ingested a dose of 10,000 mg of clozapine. Approximately 6 h after the overdose, the clozapine level was 5,200 μg/L, significantly surpassing the recommended therapeutic concentration range of 350-600 μg/L. After gastric lavage and hemoperfusion, the blood level dropped to 1847.11 μg/L. Notably, during therapeutic drugs monitoring (TDM), we found a perplexing spike in the patient's blood level to 5554.15 μg/L after the second hemoperfusion. CONCLUSION In this case we mainly focused on the abnormal fluctuations in the concentration of clozapine. We conducted a comprehensive analysis of potential factors contributing to this abnormal phenomenon in terms of the patient's age, clinical symptoms, various laboratory test indexes, and the pharmacokinetics of clozapine. Our findings underscore the importance of timely TDM and the precision of results in managing elderly patients experiencing high-dose clozapine poisoning.
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Affiliation(s)
- Yonghua Wu
- Department of Laboratory Medicine, Peking University Third Hospital, No.49, North Garden Rd, Haidian District, Beijing, 100191, China.
| | - Ziyan Zhou
- Department of Laboratory Medicine, Peking University Third Hospital, No.49, North Garden Rd, Haidian District, Beijing, 100191, China
| | - Ziyi Ai
- Department of Laboratory Medicine, Peking University Third Hospital, No.49, North Garden Rd, Haidian District, Beijing, 100191, China
| | - Tiancheng Wang
- Department of Laboratory Medicine, Peking University Third Hospital, No.49, North Garden Rd, Haidian District, Beijing, 100191, China
| | - Liyan Cui
- Department of Laboratory Medicine, Peking University Third Hospital, No.49, North Garden Rd, Haidian District, Beijing, 100191, China
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Panić B, Jovanović M, Lukić V, Vučićević K, Miljković B, Milovanović S. Association of clozapine and norclozapine levels with patient and therapy characteristics-focus on interaction with valproic acid. Eur J Clin Pharmacol 2023; 79:1557-1564. [PMID: 37733278 DOI: 10.1007/s00228-023-03569-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
PURPOSE The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use. METHODS This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients' data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ. RESULTS A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability. CONCLUSION The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.
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Affiliation(s)
- Bojana Panić
- Department of Pharmacokinetics and Clinical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221, Belgrade, Serbia
| | - Marija Jovanović
- Department of Pharmacokinetics and Clinical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221, Belgrade, Serbia.
| | - Vera Lukić
- Institute of Forensic Medicine "Milovan Milovanović", Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Katarina Vučićević
- Department of Pharmacokinetics and Clinical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221, Belgrade, Serbia
| | - Branislava Miljković
- Department of Pharmacokinetics and Clinical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221, Belgrade, Serbia
| | - Srđan Milovanović
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
- Clinic for Psychiatry, University Clinical Center of Serbia, Belgrade, Serbia
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Nia NN, Hadjmohammadi MR. Preparation of Ferrofluid from Adipic Acid Coated Magnetic Nanoparticles and Hydrophobic Deep Eutectic Solvent Used in Dispersive Micro-Solid-Phase Extraction: Application for the Pre-Concentration and Determination of Clozapine in Biological Samples. J Chromatogr Sci 2023; 61:569-578. [PMID: 36461781 DOI: 10.1093/chromsci/bmac091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Indexed: 07/20/2023]
Abstract
The aim of the present study is the preparation of a novel magnetic ferrofluid (FF) based on a hydrophobic deep eutectic solvent (DES), which is used for the extraction of trace quantities of clozapine from biological samples. For this purpose, a highly stable FF was prepared through the combination of adipic acid-coated magnetic nanoparticles (MNPs) plus tetraethylammonium chloride/thymol hDES without an additional stabilizer. These solvents were synthesized by the available and less-toxic materials, which is the appropriate option to support the solvents for the preparation of FF. In this study, a water-immiscible DES acts simultaneously as a carrier and stabilizer for the MNPs. In addition, the strong interactions between clozapine and magnetic FF could increase the extraction efficiency. The fractional factorial design was used for screening the experimental parameters. Then, the effective factors were optimized using the Box-Behnken design. The optimum extraction conditions were the following: pH of the sample solution: 8, the volume of the desorption solvent: 200 μL and desorption time: 5 min. Moreover, the suggested method exhibited low limits of detection in the range of 2.8-3.1 μg L-1. The linear range was 10.0-500.0 μg L-1 for human plasma and urine samples with acceptable recoveries greater than 91.4%. In addition, the proposed method is convenient, sensitive, effective, rapid and environmentally friendly.
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Affiliation(s)
- Negar Nooraee Nia
- Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, NirooHavayii Boulevard, 47416-95447 Babolsar, Iran
| | - Mohammad Reza Hadjmohammadi
- Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, NirooHavayii Boulevard, 47416-95447 Babolsar, Iran
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Sharif AF, Aouissi HA, Kasemy ZA, Byeon H, Lashin HI. Development and validation of a risk prediction nomogram for disposition of acute clozapine intoxicated patients to intensive care unit. Hum Exp Toxicol 2023; 42:9603271231186154. [PMID: 37379491 DOI: 10.1177/09603271231186154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
BACKGROUND Clozapine is an atypical antipsychotic drug used for the treatment of refractory schizophrenia. It is reported as the most toxic in its class. Using serum clozapine level as a severity indicator is doubtful and unfeasible, particularly in low resourced countries. METHODS This is an extended two-phase retrospective study that utilized medical records of patients diagnosed with acute clozapine intoxication and admitted to Tanta University Poison Control Center, Egypt during the past 6 years. Two hundred and eight medical records were used to establish and validate a nomogram for predicting the need for intensive care unit (ICU) admission in acute clozapine intoxicated patients. RESULTS A reliable simple bedside nomogram was developed and proved its significant ability to predict the need for ICU admission, with an area under the curve (AUC) of 83.9% and 80.8% accuracy. It encompassed the age of admitted patients (AUC = 64.8%, p = .003), respiratory rate (AUC = 74.7%, p < .001), O2 saturation (AUC = 71.7%, p < .001), and random blood glucose level upon admission (AUC = 70.5%, p < .001). External validation of the proposed nomogram showed a high AUC (99.2%) with an overall accuracy of 96.2%. CONCLUSION There is a need to develop a reliable objective tool predicting the severity and need for ICU admission in acute clozapine intoxication. The proposed nomogram is a substantially valuable tool to estimate ICU admission probabilities among patients with acute clozapine intoxication and will help clinical toxicologists make rapid decisions for ICU admission, especially in countries with low resources.
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Affiliation(s)
- Asmaa F Sharif
- Forensic Medicine and Clinical Toxicology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Clinical Medical Sciences, College of Medicine, Dar Al-Uloom University, Riyadh, Saudi Arabia
| | - H A Aouissi
- Scientific and Technical Research Center on Arid Regions (CRSTRA), Biskra, Algeria
- Laboratoire de Recherche et d'Etude en Aménagement et Urbanisme (LREAU), Université des Sciences et de la Technologie (USTHB), Algiers, Algeria
- Environmental Research Center (CRE), Badji-Mokhtar Annaba University, Annaba, Algeria
| | - Zeinab A Kasemy
- Public Health and Community Medicine Department, Faculty of Medicine, Menoufia University, Shebin El Kom, Egypt
| | - H Byeon
- Department of Digital Anti-Aging Healthcare (BK21), Inje University, Gimhae, Republic of Korea
| | - Heba I Lashin
- Forensic Medicine and Clinical Toxicology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
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Clozapine is the approved option in treatment-resistant schizophrenia and requires careful management. DRUGS & THERAPY PERSPECTIVES 2023; 39:107-113. [PMID: 36811119 PMCID: PMC9936483 DOI: 10.1007/s40267-023-00982-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2023] [Indexed: 02/19/2023]
Abstract
Clozapine is the only agent approved for treatment-resistant schizophrenia, but is underprescribed. Its adverse drug event (ADE) profile and patient monitoring requirements can discourage its use, but the benefits of clozapine generally outweigh its risks, as most ADEs are manageable. Careful patient assessment, gradual titration, minimum effective dosages, therapeutic drug monitoring and checks of neutrophils, cardiac enzymes and ADE symptoms are recommended. Neutropenia is common but does not necessarily warrant permanent clozapine cessation.
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Lereclus A, Korchia T, Riff C, Dayan F, Blin O, Benito S, Guilhaumou R. Towards Precision Dosing of Clozapine in Schizophrenia: External Evaluation of Population Pharmacokinetic Models and Bayesian Forecasting. Ther Drug Monit 2022; 44:674-682. [PMID: 35385439 DOI: 10.1097/ftd.0000000000000987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/21/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Therapeutic drug monitoring and treatment optimization of clozapine are recommended, owing to its narrow therapeutic range and pharmacokinetic (PK) variability. This study aims to assess the clinical applicability of published population PK models by testing their predictive performance in an external data set and to determine the effectiveness of Bayesian forecasting (BF) for clozapine treatment optimization. METHODS Available models of clozapine were identified, and their predictive performance was determined using an external data set (53 patients, 151 samples). The median prediction error (PE) and median absolute PE were used to assess bias and inaccuracy. The potential factors influencing model predictability were also investigated. The final concentration was reestimated for all patients using covariates or previously observed concentrations. RESULTS The 7 included models presented limited predictive performance. Only 1 model met the acceptability criteria (median PE ≤ ±20% and median absolute PE ≤30%). There was no difference between the data used for building the models (therapeutic drug monitoring or PK study) or the number of compartments in the models. A tendency for higher inaccuracy at low concentrations during treatment initiation was observed. Heterogeneities were observed in the predictive performances between the subpopulations, especially in terms of smoking status and sex. For the models included, BF significantly improved their predictive performance. CONCLUSIONS Our study showed that upon external evaluation, clozapine models provide limited predictive performance, especially in subpopulations such as nonsmokers. From the perspective of model-informed prediction dosing, model predictability should be improved using updating or metamodeling methods. Moreover, BF substantially improved model predictability and could be used for clozapine treatment optimization.
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Affiliation(s)
- Aurélie Lereclus
- Aix Marseille Université, Institut de Neurosciences des Systèmes, Inserm UMR 1106, Marseille, France
- EXACTCURE, Nice, France
| | - Théo Korchia
- Département de Psychiatrie, Sainte Marguerite University Hospital, Assistance Publique-Hôpitaux de Marseille, Marseille, France; and
| | - Camille Riff
- Service de Pharmacologie Clinique et Pharmacovigilance, Hôpital de la Timone, Marseille, France
| | | | - Olivier Blin
- Aix Marseille Université, Institut de Neurosciences des Systèmes, Inserm UMR 1106, Marseille, France
- Service de Pharmacologie Clinique et Pharmacovigilance, Hôpital de la Timone, Marseille, France
| | | | - Romain Guilhaumou
- Aix Marseille Université, Institut de Neurosciences des Systèmes, Inserm UMR 1106, Marseille, France
- Service de Pharmacologie Clinique et Pharmacovigilance, Hôpital de la Timone, Marseille, France
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13
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Vickers M, Ramineni V, Malacova E, Eriksson L, McMahon K, Moudgil V, Scott J, Siskind D. Risk factors for clozapine-induced myocarditis and cardiomyopathy: A systematic review and meta-analysis. Acta Psychiatr Scand 2022; 145:442-455. [PMID: 35067911 DOI: 10.1111/acps.13398] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/25/2021] [Accepted: 12/18/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Clozapine is the most effective medication for treatment-refractory schizophrenia, but it is associated with severe cardiac adverse events including myocarditis and cardiomyopathy. To aid treatment decision-making for clinicians, patients and their carers, we conducted a systematic review and meta-analysis to identify potential risk factors for clozapine-induced myocarditis and cardiomyopathy. METHODS A systematic search was conducted of PubMed, Embase, CINAHL, Web of Science, Cochrane and PsycInfo for studies reporting myocarditis and cardiomyopathy among people on clozapine and potential risk factors. We calculated pooled effect sizes on risk factors using a random-effects meta-analytic model. Risk of publication bias was assessed using the Newcastle-Ottawa scale. RESULTS Seven studies met the inclusion criteria, of which six studies had quantitative data included in the meta-analysis. The odds of clozapine-induced myocarditis increased with concurrent sodium valproate use (k = 6, n = 903, pooled OR 3.58, 95% CI 1.81-7.06), but were not significantly greater with the use of quetiapine, lithium or selective serotonin reuptake inhibitors. Our qualitative review identified conflicting results reported for increasing age and higher clozapine dose as risk factors for myocarditis. No other factors, including genetic risk, sex, ethnicity, smoking, alcohol, substance abuse or cardiometabolic disease, were associated with greater odds of myocarditis. No risk factors for cardiomyopathy were identified in the literature. CONCLUSION Concurrent use of sodium valproate increases the odds of clozapine-induced myocarditis. Thus, clinicians should consider the temporary cessation of sodium valproate during the initial titration phase of clozapine.
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Affiliation(s)
- Mark Vickers
- Metro North Mental Health Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia.,Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Vinay Ramineni
- Metro North Mental Health Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Eva Malacova
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Lars Eriksson
- Herston Health Sciences Library, University of Queensland, Brisbane, Queensland, Australia
| | - Kirsten McMahon
- Metro North Mental Health Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Vikas Moudgil
- Metro North Mental Health Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - James Scott
- Metro North Mental Health Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Dan Siskind
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia.,Queensland Centre for Mental Health Research, Brisbane, Queensland, Australia.,Metro South Addiction and Mental Health Service, Brisbane, Queensland, Australia
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14
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Abstract
Clozapine is the only antipsychotic with proven effectiveness in treatment-resistant schizophrenia. It is usually administered using commercially available oral tablets, but not all patients are willing or able to take medicines in this way. Orodispersible clozapine tablets are available from several manufacturers and may be useful where swallowing solid dosage forms is difficult, or as an aid to observe compliance. Liquid formulations of clozapine can be prepared extemporaneously or purchased commercially, but most preparations are suspensions (clozapine is poorly soluble) and patients may find them unpalatable. The administration of clozapine (suspension or crushed tablets) via enteral feeding tubes (predominantly nasogastric) has been reported both in medically unwell patients and in patients refusing clozapine. Enteral administration is likely to be superseded by intramuscular clozapine, which has recently been re-introduced and is being widely used in some countries. Successful use of this formulation in enforced treatment strategies has been described by several authors with good long-term outcomes when switched to oral treatment. Intramuscular clozapine has also been used in physically ill patients who are unable to take any form of enteral medication. Other methods of delivery (transdermal, nasal) are not yet commercially available, but offer promise of further treatment options for this group of seriously ill patients.
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Affiliation(s)
- Siobhan Gee
- Pharmacy Department, South London and Maudsley NHS Foundation Trust, London, UK.
| | - David Taylor
- Pharmacy Department, South London and Maudsley NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
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15
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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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16
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Xin J, Yan S, Hong X, Zhang H, Zha J. Environmentally relevant concentrations of clozapine induced lipotoxicity and gut microbiota dysbiosis in Chinese rare minnow (Gobiocypris rarus). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117298. [PMID: 33964688 DOI: 10.1016/j.envpol.2021.117298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/10/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Clozapine (CLZ) is a neuroactive pharmaceutical that is frequently detected in aquatic environments. Although the cardiotoxicity, developmental toxicity, and neurotoxicity of CLZ in aquatic non-target organisms have been reported, its lipotoxicity and underlying mechanism are unknown. Therefore, in this study, 2-month-old Chinese rare minnows were exposed to 0, 0.1, 1, and 10 μg/L CLZ for 90 days. Overt dyslipidemia was observed after CLZ exposure, whereas the body weights of females significantly increased after CLZ exposure (p < 0.05). In addition, obvious hepatocyte vacuolization and hepatic lipid droplet accumulation were observed at all treatment groups (p < 0.05). The activities of sterol regulatory element binding proteins 1 (SREBP1) and fatty acid synthase (FAS) were significantly upregulated at the 1 and 10 μg/L CLZ treatment groups (p < 0.05). Moreover, evident cell boundary disintegration of the intestinal villi and increasing mucus secretion were observed at all treatment groups (p < 0.05). Furthermore, the diversity of the gut microbiota increased, whereas the relative abundances of Proteobacteria, Firmicutes and Bacteroidetes significantly increased after CLZ exposure (p < 0.05). Furthermore, significantly increased bacterial secondary bile acid biosynthesis activity in Chinese rare minnows was observed after 1 μg/L CLZ exposure (p < 0.05). Therefore, our findings confirmed that CLZ induced lipotoxicity by stimulating SREBP1 and affecting the bacterial secondary bile acid biosynthesis activity in Chinese rare minnows.
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Affiliation(s)
- Jiajing Xin
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Saihong Yan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiangsheng Hong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huan Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agriculture University, Wuhan, 430070, China
| | - Jinmiao Zha
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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17
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Seeman MV, González-Rodríguez A. Stratification by Sex and Hormone Level When Contrasting Men and Women in Schizophrenia Trials Will Improve Personalized Treatment. J Pers Med 2021; 11:929. [PMID: 34575706 PMCID: PMC8471344 DOI: 10.3390/jpm11090929] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Sex and gender differences have been reported in the prevalence, expression, treatment response, and outcome of schizophrenia, but most reports are based on relatively small samples that have not been stratified for the impact of sex hormone levels. This literature review aims to show how women's hormone levels can impact the results of male/female comparisons. METHODS This is a narrative review of data from publications of the last decade. RESULTS Epidemiologic evidence, reports of the impact of hormones on cognition, results of sexually dimorphic responses to treatment, and male/female trajectories of illness over time all suggest that female hormone fluctuations exert major effects on male/female differences in schizophrenia. CONCLUSIONS Information on hormonal status in women participants is rarely available in clinical studies in schizophrenia, which makes male/female comparisons largely uninterpretable. These are the current challenges. Opportunities for individualized treatment are growing, however, and will undoubtedly result in improved outcomes for both women and men in the future.
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Affiliation(s)
- Mary V. Seeman
- Department of Psychiatry, University of Toronto, #605 260 Heath St. W., Toronto, ON M5P 3L6, Canada
| | - Alexandre González-Rodríguez
- Department of Mental Health, Mutua Terrassa University Hospital, University of Barcelona, 08221 Terrassa, Barcelona, Spain;
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18
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Lee J, Kim MG, Jeong HC, Shin KH. Physiologically-based pharmacokinetic model for clozapine in Korean patients with schizophrenia. Transl Clin Pharmacol 2021; 29:33-44. [PMID: 33854999 PMCID: PMC8020364 DOI: 10.12793/tcp.2021.29.e3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/18/2022] Open
Abstract
Clozapine has been used as a treatment of schizophrenia. Despite its large interindividual variability, few reports addressed the physiologically-based pharmacokinetic modeling and simulation (PBPK M&S) of clozapine in patients. This study aimed to develop a PBPK M&S of clozapine in Korean patients with schizophrenia. PBPK modeling for clozapine was constructed using a population-based PBPK platform, the SimCYP® Simulator (V19; Certara, Sheffield, UK). The PBPK model was developed by optimizing the physiological parameters of the built-in population and compound libraries in the SimCYP® Simulator. The model verification was performed with the predicted/observed ratio for pharmacokinetic parameters and visual predictive checks (VPCs) plot. Simulations were performed to predict toxicities according to dosing regimens. From published data, 230 virtual trials were simulated for each dosing regimen. The predicted/observed ratio for the area under the curve and peak plasma concentration was calculated to be from 0.78 to 1.34. The observation profiles were within the 5th and 95th percentile range with no serious model misspecification through the VPC plot. A significant impact on age and gender was found for clozapine clearance. The simulation results suggested that 150 mg twice a day and 150 mg three times a day of clozapine have toxicity concerns. In conclusion, a PBPK model was developed and reasonable parameters were made from the data of Korean patients with schizophrenia. The provided model might be used to predict the pharmacokinetics of clozapine and assist dose adjustment in clinical settings.
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Affiliation(s)
- Joomi Lee
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Min-Gul Kim
- Center for Clinical Pharmacology and Biomedical Research Institute, Jeonbuk National University Hospital, Jeonju 54907, Korea.,Department of Pharmacology, School of Medicine, Jeonbuk National University, Jeonju 54907, Korea
| | - Hyeon-Cheol Jeong
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Kwang-Hee Shin
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 41566, Korea
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19
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Kuzin M, Haen E, Hiemke C, Bochon B, Bochon K, Gründer G, Paulzen M, Schoretsanitis G. Body mass index as a determinant of clozapine plasma concentrations: A pharmacokinetic-based hypothesis. J Psychopharmacol 2021; 35:273-278. [PMID: 33546578 DOI: 10.1177/0269881120985166] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Knowledge regarding the impact of body composition measures on pharmacokinetics of antipsychotics is limited. AIMS Our aim was to investigate the impact of body weight and body mass index on clozapine pharmacokinetics using a therapeutic drug monitoring database. METHODS A large therapeutic drug monitoring dataset of clozapine plasma concentrations considering three patient subgroups was analysed: a control group (CLZ0, 20-30 kg/m2, n=266), a group with high body mass index (CLZhigh, body mass index ⩾30 kg/m2, n=162) and with low body mass index values (CLZlow, body mass index <20 kg/m2, n=27). Comparisons of plasma and dose-adjusted plasma concentrations (C/D) of clozapine were based on the Spearman's correlation (rs), Kruskal Wallis and Mann-Whitney-U tests. For percentages we used the Pearson chi-square test (χ2). To assess effects of confounders we used bootstrapping analysis of covariates. RESULTS/OUTCOMES Regarding demographic characteristics, groups differed only for sex percentage with more females than males in CLZlow and CLZhigh compared to CLZ0 (p=0.001 for χ2 test). Plasma and C/D values were positively associated with body mass index (rs=0.108, p=0.022 and rs=0.156, p=0.001 respectively). Intergroup differences were observed for plasma and dose-adjusted concentrations of clozapine (p=0.031 and p=0.029 for Kruskal Wallis respectively): post-hoc pairwise comparisons showed higher plasma concentrations and C/D of clozapine in CLZhigh compared to CLZ0 (p=0.014 and p=0.007 respectively for Mann-Whitney U-test), by mean 21 and 18%, respectively. Differences for C/D values remained after accounting for sex (p=0.02). CONCLUSIONS/INTERPRETATION In obese patients, bioavailability, distribution or elimination of clozapine may be altered due to increased clozapine deposits in fat tissue and hepatic enzyme activity changes.
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Affiliation(s)
- Maxim Kuzin
- Clienia Schloessli, Private Psychiatric Hospital and Academic Teaching Hospital of the University of Zurich, Zurich, Switzerland
| | - Ekkehard Haen
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany.,Department of Pharmacology and Toxicology, University of Regensburg, Regensburg, Germany
| | - Christoph Hiemke
- Department of Psychiatry and Psychotherapy, University Medical Center of Mainz, Mainz, Germany.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center of Mainz, Mainz, Germany
| | - Benjamin Bochon
- Psychiatric Services of Thurgovia, Academic Teaching Hospital of the Medical University of Salzburg, Münsterlingen, Switzerland
| | | | - Gerhard Gründer
- Department of Molecular Neuroimaging, University of Heidelberg, Mannheim, Germany
| | - Michael Paulzen
- Alexianer Hospital Aachen, Aachen, Germany.,JARA - Translational Brain Medicine, Jülich, Germany
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20
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Azorin JM, Simon N. Antipsychotic polypharmacy in schizophrenia: evolving evidence and rationale. Expert Opin Drug Metab Toxicol 2020; 16:1175-1186. [DOI: 10.1080/17425255.2020.1821646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Nicolas Simon
- Department of Clinical Pharmacology, Aix Marseille University, INSERM, IRD, SESSTIM, Marseille, France
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21
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Jovanović M, Vučićević K, Miljković B. Understanding variability in the pharmacokinetics of atypical antipsychotics - focus on clozapine, olanzapine and aripiprazole population models. Drug Metab Rev 2020; 52:1-18. [PMID: 32008418 DOI: 10.1080/03602532.2020.1717517] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Antipsychotic medicines are widely used for the management of psychotic symptoms regardless of the underlying diagnosis. Most atypical antipsychotics undergo extensive metabolism prior to excretion. Various factors may influence their pharmacokinetics, particularly elimination, leading to highly variable drug concentrations between individual patients following the same dosing regimen. Population pharmacokinetic approach, based on nonlinear mixed effects modeling, is a useful tool to identify covariates explaining pharmacokinetic variability, as well as to characterize and distinguish unexplained residual and between-subject (interindividual) variability. In addition, this approach allows the use of both sparsely and intensively sampled data. In this paper, we reviewed the pharmacokinetic characteristics of clozapine, olanzapine and aripiprazole, focusing on a population modeling approach. In particular, models based on a nonlinear mixed effects approach performed by NONMEM® software in order to identify and quantify sources of pharmacokinetic variability are presented. Population models were identified through systematic searches of PubMed and sixteen studies were selected. Some of the factors identified that significantly contribute to variability in elimination among clozapine, olanzapine, and aripiprazole are demographic characteristics, body weight, genetic polymorphism, smoking and in some cases drug interactions. Scientific research based on pharmacometric modeling is useful to further characterize sources of variability and their combined effect.
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Affiliation(s)
- Marija Jovanović
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
| | - Katarina Vučićević
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
| | - Branislava Miljković
- Department of Pharmacokinetics and Clinical Pharmacy, University of Belgrade - Faculty of Pharmacy, Belgrade, Republic of Serbia
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22
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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] [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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23
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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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24
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Dabba K, Elswood M, Ameer A, Gerrett D, Maidment I. A mixed methods analysis of clozapine errors reported to the National Reporting and Learning System. Pharmacoepidemiol Drug Saf 2019; 28:657-664. [DOI: 10.1002/pds.4727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 10/22/2018] [Accepted: 12/09/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Keval Dabba
- PharmacyNottinghamshire Healthcare Foundation Trust Nottingham UK
| | - Matthew Elswood
- PharmacyNottinghamshire Healthcare Foundation Trust Nottingham UK
| | - Ahmed Ameer
- Patient SafetyNHS Improvement, NHS London UK
| | | | - Ian Maidment
- Life & Health SciencesAston University Birmingham UK
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25
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Abstract
Clozapine is the first second generation antipsychotic with different receptor profile of action. Clozapine is the most efficacious drug for the treatment of psychotic disorder and is the drug of choice in treatment resistant schizophrenia. Clozapine is used in elderly patients infrequently owing to its adverse effects profile and tolerability. There is paucity of literature with respect to clozapine use in late life. In this narrative review, we discuss clozapine use in elderly and challenges associated with its use.
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Affiliation(s)
- Shiva Shanker Reddy Mukku
- Geriatric Clinic & Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
| | - P T Sivakumar
- Geriatric Clinic & Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
| | - Mathew Varghese
- Geriatric Clinic & Services, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
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Castberg I, Westin AA, Skogvoll E, Spigset O. Effects of age and gender on the serum levels of clozapine, olanzapine, risperidone, and quetiapine. Acta Psychiatr Scand 2017; 136:455-464. [PMID: 28865402 DOI: 10.1111/acps.12794] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/02/2017] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To investigate serum concentrations of second-generation antipsychotics in relation to age and gender in a population ranging from 18 to 100 years. METHOD Results from a routine therapeutic drug monitoring database were retrieved, and 43 079 samples from 11 968 patients were included (17 249 samples for clozapine, 16 171 samples for olanzapine, 5343 samples for risperidone, and 4316 samples for quetiapine). The dose-adjusted concentration was used as the primary target variable. A linear mixed model was used to allow the inclusion of multiple samples from each patient. RESULTS Age had a significant impact on the concentrations of all four drugs. At the age of 80, the dose-adjusted concentrations were up to twice those of the age of 40. At the age of 90, dose-adjusted concentrations were two- to three-fold higher. Age-related increases were largest for clozapine (+108% at 80 years; +197% at 90 years) and smallest for olanzapine (+28% at 80 years; +106% at 90 years). Females generally had dose-adjusted concentrations 20-30% higher than males. CONCLUSION The effect of age on the serum concentrations of the antipsychotics studied becomes pronounced with advanced age. The patient population aged above 70 should be subdivided according to exact age, and considerable dose reductions are recommended.
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Affiliation(s)
- I Castberg
- Østmarka Psychiatric Department, St. Olav University Hospital, Trondheim, Norway
| | - A A Westin
- Department of Clinical Pharmacology, St. Olav University Hospital, Trondheim, Norway.,Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway
| | - E Skogvoll
- Department of Anaesthesiology and Intensive Care, St. Olav University Hospital, Trondheim, Norway
| | - O Spigset
- Department of Clinical Pharmacology, St. Olav University Hospital, Trondheim, Norway.,Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway
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Pringsheim T, Kelly M, Urness D, Teehan M, Ismail Z, Gardner D. Physical Health and Drug Safety in Individuals with Schizophrenia. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2017; 62:673-683. [PMID: 28718324 PMCID: PMC5593246 DOI: 10.1177/0706743717719898] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND While antipsychotic medications are the mainstay of therapy for individuals with schizophrenia and psychotic disorders, their use is associated with adverse effects on physical health that require the attention and care of prescribers. METHODS We used the ADAPTE process to adapt existing guideline recommendations from the National Institute for Health and Care Excellence (NICE) and Scottish Intercollegiate Guidelines Network (SIGN) guidelines on the dosing of antipsychotics and antipsychotic polypharmacy, screening for adverse effects of antipsychotics, and management of metabolic and extrapyramidal side effects to the Canadian context. RESULTS Prescribers are encouraged to use the lowest effective dose and to avoid the routine use of multiple antipsychotics. Scheduled monitoring of body mass index, waist circumference, blood pressure, glucose, lipids, prolactin, electrocardiograms, and extrapyramidal symptoms is recommended. Lifestyle interventions are recommended to mitigate antipsychotic-induced weight gain. Prescribers should follow Canadian guidelines on the treatment of obesity, dyslipidemia, and diabetes. Recommendations on antipsychotic drug choice are made for users particularly concerned about extrapyramidal symptoms. CONCLUSION Careful monitoring and attention by prescribers may mitigate adverse effects associated with antipsychotic medications.
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Affiliation(s)
- Tamara Pringsheim
- 1 Department of Clinical Neurosciences, Psychiatry, Pediatrics and Community Health Sciences, University of Calgary, Calgary, Alberta
| | - Martina Kelly
- 2 Department of Family Medicine, University of Calgary, Alberta
| | - Doug Urness
- 3 Clinical Department Head, Addiction and Mental Health, Central Zone, Alberta Health Services, Edmonton, Alberta
| | - Michael Teehan
- 4 Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia
| | - Zahinoor Ismail
- 5 Department of Psychiatry and Clinical Neurosciences, University of Calgary, Calgary, Alberta
| | - David Gardner
- 6 Department of Psychiatry and College of Pharmacy, Dalhousie University, Halifax, Nova Scotia
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Abstract
We aimed to evaluate the association between sex and hospitalization characteristics in psychotic disorders. We identified all acute hospitalizations, between 2010 and 2013, for psychotic disorders in patients younger than 45 and older than 55 years (n = 5411) in the hospital's database. In addition, we identified patients who were prescribed with intramuscular risperidone (n = 280) or clozapine (n = 192) at discharge. The results showed that women younger than 45 years had lower proportions of hospitalizations (33.52% vs. 66.47%) and involuntary hospitalizations (33.85% vs. 45.55%) than did men in the same age group. Women older than 55 years had higher proportions of hospitalizations (57.22% vs. 42.77%) and similar proportion of involuntary hospitalizations. Women younger than 45 years were prescribed similar doses of intramuscular risperidone and lower doses of clozapine (345.8 vs. 380.2 mg) and women older than 55 years were prescribed higher doses of intramuscular risperidone (44.8 vs. 34.4 mg/2 weeks) and clozapine (164.32 vs. 154.5 mg) than were men in the same age group. Women in the reproductive years have better hospitalization characteristics than do men on these measures.
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Rouhollahi A, Kouchaki M, Seidi S. Electrically stimulated liquid phase microextraction combined with differential pulse voltammetry: a new and efficient design for in situ determination of clozapine from complicated matrices. RSC Adv 2016. [DOI: 10.1039/c5ra25157e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Electromembrane extraction combined with differential pulse voltammetry for in situ determination of clozapine from complicated matrices.
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Affiliation(s)
- Ahmad Rouhollahi
- Department of Analytical Chemistry
- Faculty of Chemistry
- K. N. Toosi University of Technology
- Tehran
- Iran
| | - Masoomeh Kouchaki
- Department of Analytical Chemistry
- Faculty of Chemistry
- K. N. Toosi University of Technology
- Tehran
- Iran
| | - Shahram Seidi
- Department of Analytical Chemistry
- Faculty of Chemistry
- K. N. Toosi University of Technology
- Tehran
- Iran
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Perera V, Bies RR, Mo G, Dolton MJ, Carr VJ, McLachlan AJ, Day RO, Polasek TM, Forrest A. Optimal sampling of antipsychotic medicines: a pharmacometric approach for clinical practice. Br J Clin Pharmacol 2015; 78:800-14. [PMID: 24773369 DOI: 10.1111/bcp.12410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/19/2014] [Indexed: 11/28/2022] Open
Abstract
AIM To determine optimal sampling strategies to allow the calculation of clinical pharmacokinetic parameters for selected antipsychotic medicines using a pharmacometric approach. METHODS This study utilized previous population pharmacokinetic parameters of the antipsychotic medicines aripiprazole, clozapine, olanzapine, perphenazine, quetiapine, risperidone (including 9-OH risperidone) and ziprasidone. d-optimality was utilized to identify time points which accurately predicted the pharmacokinetic parameters (and expected error) of each drug at steady-state. A standard two stage population approach (STS) with MAP-Bayesian estimation was used to compare area under the concentration-time curves (AUC) generated from sparse optimal time points and rich extensive data. Monte Carlo Simulation (MCS) was used to simulate 1000 patients with population variability in pharmacokinetic parameters. Forward stepwise regression analysis was used to determine the most predictive time points of the AUC for each drug at steady-state. RESULTS Three optimal sampling times were identified for each antipsychotic medicine. For aripiprazole, clozapine, olanzapine, perphenazine, risperidone, 9-OH risperidone, quetiapine and ziprasidone the CV% of the apparent clearance using optimal sampling strategies were 19.5, 8.6, 9.5, 13.5, 12.9, 10.0, 16.0 and 10.7, respectively. Using the MCS and linear regression approach to predict AUC, the recommended sampling windows were 16.5-17.5 h, 10-11 h, 23-24 h, 19-20 h, 16.5-17.5 h, 22.5-23.5 h, 5-6 h and 5.5-6.5 h, respectively. CONCLUSION This analysis provides important sampling information for future population pharmacokinetic studies and clinical studies investigating the pharmacokinetics of antipsychotic medicines.
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Affiliation(s)
- Vidya Perera
- School of Pharmacy and Pharmaceutical Sciences, School of Pharmacy, SUNY at Buffalo, Buffalo, NY, USA; Schizophrenia Research Institute, Sydney, Australia
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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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Therapeutic window for striatal dopamine D(2/3) receptor occupancy in older patients with schizophrenia: a pilot PET study. Am J Geriatr Psychiatry 2014; 22:1007-16. [PMID: 25217025 DOI: 10.1016/j.jagp.2013.01.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 01/21/2012] [Accepted: 02/27/2012] [Indexed: 11/23/2022]
Abstract
OBJECTIVE In younger patients with schizophrenia, positron emission tomography (PET) studies have identified a therapeutic window of striatal dopamine D(2/3) receptor occupancy of 65%-80%. This type of empirical information is not available in late life. Our primary aim was to assess the effect of changes in D(2/3) relative receptor occupancy (RRO) on clinical outcomes in this population. DESIGN Open-label intervention. SETTING Centre for Addiction and Mental Health, Toronto. PARTICIPANTS Subjects with schizophrenia age 50 years or more who were clinically stable and previously maintained on oral risperidone for D(2/3) RRO in dorsal putamen was assessed, using the region of interest analysis of [¹¹C]raclopride PET scans, before and after the dose reduction. Clinical assessments included the Positive and Negative Syndrome Scale and the Simpson-Angus Scale. RESULTS Nine subjects (mean ± SD age: 58 ± 7 years; mean ± SD baseline risperidone dose: 3.4 ± 1.6 mg/day) participated in the study. Extrapyramidal symptoms (EPS) were present in six subjects and were associated with 70% or more D(2/3) RRO in the putamen (range: 70%-87%). Following the dose reduction, EPS resolved in five subjects. Two subjects experienced a clinical worsening at 52% and at less than 50% D(2/3) RRO. CONCLUSION EPS diminished less than 70% D(2/3) RRO, which suggests a lower therapeutic window for older patients with schizophrenia than that for younger patients. Although these findings have to be replicated in a larger sample, they have important implications for future drug development and clinical guidelines in late-life schizophrenia.
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Li CH, Stratford RE, Velez de Mendizabal N, Cremers TIFH, Pollock BG, Mulsant BH, Remington G, Bies RR. Prediction of brain clozapine and norclozapine concentrations in humans from a scaled pharmacokinetic model for rat brain and plasma pharmacokinetics. J Transl Med 2014; 12:203. [PMID: 25142323 PMCID: PMC4261612 DOI: 10.1186/1479-5876-12-203] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/08/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Clozapine is highly effective in treatment-resistant schizophrenia, although, there remains significant variability in the response to this drug. To better understand this variability, the objective of this study was to predict brain extracellular fluid (ECF) concentrations and receptor occupancy of clozapine and norclozapine in human central nervous system by translating plasma and brain ECF pharmacokinetic (PK) relationships in the rat and coupling these with known human disposition of clozapine in the plasma. METHODS Unbound concentrations of clozapine and norclozapine were measured in rat brain ECF using quantitative microdialysis after subcutaneous administration of a 10 mg/kg single dose of clozapine or norclozapine. These data were linked with plasma concentrations obtained in the same rats to develop a plasma-brain ECF compartmental model. Parameters describing brain ECF disposition were then allometrically scaled and linked with published human plasma PK to predict human ECF concentrations. Subsequently, prediction of human receptor occupancy at several CNS receptors was based on an effect model that related the predicted ECF concentrations to published concentration-driven receptor occupancy parameters. RESULTS A one compartment model with first order absorption and elimination best described clozapine and norclozapine plasma concentrations in rats. A delay in the transfer of clozapine and norclozapine from plasma to the brain ECF compartment was captured using a transit compartment model approach. Human clozapine and norclozapine concentrations in brain ECF were simulated, and from these the median percentage of receptor occupancy of dopamine-2, serotonin-2A, muscarinic-1, alpha-1 adrenergic, alpha-2 adrenergic and histamine-1 for clozapine, and dopamine-2 for norclozapine were consistent with values reported in the literature. CONCLUSIONS A PK model that relates clozapine and norclozapine disposition in rat plasma and brain, including blood-brain barrier transport, was developed. Using allometry and published human plasma PK, the model was successfully translated to predict clozapine and norclozapine concentrations and accordant receptor occupancy of both agents in human brain. These predicted exposure and occupancy measures at several receptors that bind clozapine may be employed to extend our understanding of clozapine's complex behavioral effects in humans.
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Affiliation(s)
| | | | | | | | | | | | | | - Robert R Bies
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 1001 W, 10th Street W7138, Indianapolis, IN 46202, USA.
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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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Kohlrausch FB, Severino-Gama C, Lobato MI, Belmonte-de-Abreu P, Carracedo A, Hutz MH. The CYP1A2 -163C>A polymorphism is associated with clozapine-induced generalized tonic-clonic seizures in Brazilian schizophrenia patients. Psychiatry Res 2013; 209:242-5. [PMID: 23601795 DOI: 10.1016/j.psychres.2013.02.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/04/2013] [Accepted: 02/21/2013] [Indexed: 11/26/2022]
Abstract
We evaluated two polymorphisms at CYP1A2 (*1C and *1F) in a sample of 108 European-derived patients with schizophrenia and their influence on the pro-convulsive effect of clozapine. We found the *1F/*1F genotype to be significantly associated with seizures, and no relationship was observed with combinations of *1F and *1C alleles.
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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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Sakurai H, Bies RR, Stroup ST, Keefe RSE, Rajji TK, Suzuki T, Mamo DC, Pollock BG, Watanabe K, Mimura M, Uchida H. Dopamine D2 receptor occupancy and cognition in schizophrenia: analysis of the CATIE data. Schizophr Bull 2013; 39:564-74. [PMID: 22290266 PMCID: PMC3627781 DOI: 10.1093/schbul/sbr189] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Antipsychotic drugs exert antipsychotic effects by blocking dopamine D2 receptors in the treatment of schizophrenia. However, effects of D2 receptor blockade on neurocognitive function still remain to be elucidated. The objective of this analysis was to evaluate impacts of estimated dopamine D2 receptor occupancy with antipsychotic drugs on several domains of neurocognitive function in patients with schizophrenia in the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) trial. METHODS The dataset from the CATIE trial was used in the present analysis. Data were extracted from 410 subjects who were treated with risperidone, olanzapine, or ziprasidone, received assessments for neurocognitive functions (verbal memory, vigilance, processing speed, reasoning, and working memory) and psychopathology, and provided plasma samples for the measurement of plasma antipsychotic concentrations. D2 receptor occupancy levels on the day of neurocognitive assessment were estimated from plasma antipsychotic concentrations, using population pharmacokinetic analysis and our recently developed model. A multivariate general linear model was used to examine effects of clinical and demographic characteristics, including estimated D2 occupancy levels, on neurocognitive functions. RESULTS D2 occupancy levels showed significant associations with the vigilance and the summary scores. Neurocognitive functions, including vigilance, were especially impaired in subjects who showed D2 receptor occupancy level of >77%. DISCUSSION These findings suggest a nonlinear relationship between prescribed antipsychotic doses and overall neurocognitive function and vigilance. This study shows that D2 occupancy above approximately 80% not only increases the risk for extrapyramidal side effects as consistently reported in the literature but also increases the risk for cognitive impairment.
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Affiliation(s)
- Hitoshi Sakurai
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Robert R. Bies
- Geriatric Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, IN,Indiana Clinical and Translational Sciences Institute, Indianapolis, IN
| | - Scott T. Stroup
- College of Physicians and Surgeons, Columbia University, New York, NY
| | - Richard S. E. Keefe
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC
| | - Tarek K. Rajji
- Geriatric Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Takefumi Suzuki
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - David C. Mamo
- Geriatric Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Multimodal Imaging Group, PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Bruce G. Pollock
- Geriatric Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Koichiro Watanabe
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan,Geriatric Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada,To whom correspondence should be addressed; tel: 81-3-5363-3829, fax: 81-3-5379-0187, e-mail:
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Population pharmacokinetics of clozapine and its primary metabolite norclozapine in Chinese patients with schizophrenia. Acta Pharmacol Sin 2012; 33:1409-16. [PMID: 22820910 DOI: 10.1038/aps.2012.71] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AIM To develop a combined population pharmacokinetic model (PPK) to assess the magnitude and variability of exposure to both clozapine and its primary metabolite norclozapine in Chinese patients with refractory schizophrenia via sparse sampling with a focus on the effects of covariates on the pharmacokinetic parameters. METHODS Relevant patient concentration data (eg, demographic data, medication history, dosage regimen, time of last dose, sampling time, concentrations of clozapine and norclozapine, etc) were collected using a standardized data collection form. The demographic characteristics of the patients, including sex, age, weight, body surface area, smoking status, and information on concomitant medications as well as biochemical and hematological test results were recorded. Persons who had smoked 5 or more cigarettes per day within the last week were defined as smokers. The concentrations of clozapine and norclozapine were measured using a HPLC system equipped with a UV detector. PPK analysis was performed using NONMEM. Age, weight, sex, and smoking status were evaluated as main covariates. The model was internally validated using normalized prediction distribution errors. RESULTS A total of 809 clozapine concentration data sets and 808 norclozapine concentration data sets from 162 inpatients (74 males, 88 females) at multiple mental health sites in China were included. The one-compartment pharmacokinetic model with mixture error could best describe the concentration-time profiles of clozapine and norclozapine. The population-predicted clearance of clozapine and norclozapine in female nonsmokers were 21.9 and 32.7 L/h, respectively. The population-predicted volumes of distribution for clozapine and norclozapine were 526 and 624 L, respectively. Smoking was significantly associated with increases in the clearance (clozapine by 45%; norclozapine by 54.3%). The clearance was significantly greater in males than in females (clozapine by 20.8%; norclozapine by 24.2%). The clearance of clozapine and norclozapine did not differ significantly between Chinese patients and American patients. CONCLUSION Smoking and male were significantly associated with a lower exposure to clozapine and norclozapine due to higher clearance. This model can be used in individualized drug dosing and therapeutic drug monitoring.
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Bowskill S, Couchman L, MacCabe JH, Flanagan RJ. Plasma clozapine and norclozapine in relation to prescribed dose and other factors in patients aged 65 years and over: data from a therapeutic drug monitoring service, 1996-2010. Hum Psychopharmacol 2012; 27:277-83. [PMID: 22419536 DOI: 10.1002/hup.2223] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/12/2012] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To investigate the effect of dose and other factors on plasma clozapine concentrations in patients aged 65 years and over. METHOD Audit of clozapine therapeutic drug monitoring data, 1996-2010. RESULTS There were 1930 samples [778 patients, 363 men aged (median, range) 67 (65-100) years and 415 women aged 68 (65-90) years]. There was no significant difference in the mean plasma clozapine concentration between men (0.56 mg/l) and women (0.58 mg/l), although the mean dose was higher in men (323 mg/d) than women (264 mg/d). The higher proportion of men (46%) compared with women (37%) smokers could explain this finding. Overall, 32% of samples had plasma clozapine below, and 37% above, a target range of 0.35-0.60 mg/l. Overall, the median dose decreased from 300 (65-70 years) to 200 mg/d (age 85 years and over). However, prescription of >350 mg/d was associated with a 50% likelihood that the plasma clozapine would exceed 0.60 mg/l. For a subgroup of 196 patients (114 men, 82 women), mean plasma clozapine was significantly higher after age 65 despite significantly lower dosage. CONCLUSION Clozapine dosage in elderly patients should be reviewed regularly to minimise the risk of adverse effects.
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Affiliation(s)
- Sally Bowskill
- Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK
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