1
|
Schoretsanitis G, Baumann P, Conca A, Dietmaier O, Giupponi G, Gründer G, Hahn M, Hart X, Havemann-Reinecke U, Hefner G, Kuzin M, Mössner R, Piacentino D, Steimer W, Zernig G, Hiemke C. Therapeutic Drug Monitoring of Long-Acting Injectable Antipsychotic Drugs. Ther Drug Monit 2021; 43:79-102. [PMID: 33196621 DOI: 10.1097/ftd.0000000000000830] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND The use of therapeutic drug monitoring (TDM) to guide treatment with long-acting injectable (LAI) antipsychotics, which are increasingly prescribed, remains a matter of debate. The aim of this review was to provide a practical framework for the integration of TDM when switching from an oral formulation to the LAI counterpart, and in maintenance treatment. METHODS The authors critically reviewed 3 types of data: (1) positron emission tomography data evaluating dopamine (D2/D3) receptor occupancy related to antipsychotic concentrations in serum or plasma; D2/D3 receptors are embraced as target sites in the brain for antipsychotic efficacy and tolerability, (2) pharmacokinetic studies evaluating the switch from oral to LAI antipsychotics, and (3) pharmacokinetic data for LAI formulations. Based on these data, indications for TDM and therapeutic reference ranges were considered for LAI antipsychotics. RESULTS Antipsychotic concentrations in blood exhibited interindividual variability not only under oral but also under LAI formulations because these concentrations are affected by demographic characteristics such as age and sex, genetic peculiarities, and clinical variables, including comedications and comorbidities. Reported data combined with positron emission tomography evidence indicated a trend toward lower concentrations under LAI administration than under oral medications. However, the available evidence is insufficient to recommend LAI-specific therapeutic reference ranges. CONCLUSIONS Although TDM evidence for newer LAI formulations is limited, this review suggests the use of TDM when switching an antipsychotic from oral to its LAI formulation. The application of TDM practice is more accurate for dose selection than the use of dose equivalents as it accounts more precisely for individual characteristics.
Collapse
Affiliation(s)
| | - Pierre Baumann
- Department of Psychiatry, University of Lausanne, Prilly-Lausanne, Switzerland
| | - Andreas Conca
- Department of Psychiatry, Central Hospital, Sanitary Agency of South Tyrol, Bolzano, Italy
| | - Otto Dietmaier
- Psychiatric Hospital, Klinikum am Weissenhof, Weinsberg, Germany
| | - Giancarlo Giupponi
- Department of Psychiatry, Central Hospital, Sanitary Agency of South Tyrol, Bolzano, Italy
| | - Gerhard Gründer
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Martina Hahn
- Department of Psychiatry and Psychotherapy, University of Frankfurt, Frankfurt, Germany
| | - Xenia Hart
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Gudrun Hefner
- Forensic Psychiatric Hospital, Vitos Klinik, Eichberg, Eltville, Germany
| | - Maxim Kuzin
- Psychiatric and Psychotherapeutic Private Clinic Clienia Schlössli, Academic Teaching Hospital of the University of Zurich, Oetwil am See, Switzerland
| | - Rainald Mössner
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Daria Piacentino
- Department of Psychiatry, Central Hospital, Sanitary Agency of South Tyrol, Bolzano, Italy
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, National Institute on Drug Abuse Intramural Research Program, National Institute on Alcohol Abuse and Alcoholism, Division of Intramural Clinical and Biological Research, National Institutes of Health, Bethesda, MD
| | - Werner Steimer
- Institute of Clinical Chemistry and Pathobiochemistry, Technical University Munich, Munich, Germany
| | - Gerald Zernig
- Department of Psychiatry, Medical University of Innsbruck, Innsbruck, Austria
- Private Practice for Psychotherapy and Court-Certified Witness, Hall in Tirol, Austria ; and
| | - Christoph Hiemke
- Department of Psychiatry and Psychotherapy, Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center of Mainz, Mainz, Germany
| |
Collapse
|
2
|
Waade RB, Solhaug V, Høiseth G. Impact of CYP2D6 on serum concentrations of flupentixol, haloperidol, perphenazine and zuclopenthixol. Br J Clin Pharmacol 2020; 87:2228-2235. [PMID: 33118660 DOI: 10.1111/bcp.14626] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/14/2020] [Accepted: 10/13/2020] [Indexed: 12/12/2022] Open
Abstract
AIMS To investigate the impact of cytochrome P450 2D6 (CYP2D6) on dose-adjusted serum concentrations of flupentixol, haloperidol, perphenazine and zuclopenthixol in a therapeutic drug monitoring (TDM) cohort of psychiatric patients. We also studied the functional impact of CYP2D6*41 on dose-adjusted serum concentrations in the perphenazine-treated patients. METHODS Serum concentrations of flupentixol, haloperidol, perphenazine and zuclopenthixol from CYP-genotyped patients were extracted retrospectively from a routine TDM database in the period March 2005 to May 2019. Samples were divided into three CYP2D6 phenotype subgroups according to genotype; normal metabolizers (NMs), intermediate metabolizers (IMs) and poor metabolizers (PMs). The effect of CYP2D6 phenotype on dose-adjusted serum concentrations of the four antipsychotics was evaluated by multivariable mixed model analyses. RESULTS Mean dose-adjusted serum concentrations of perphenazine (564 samples) were 3.9-fold and 1.6-fold higher in CYP2D6 PMs and IMs, respectively, compared with NMs (P < .001 and P < .01). For zuclopenthixol (658 samples), mean dose-adjusted serum concentrations were about 1.5-fold and 1.3-fold higher in CYP2D6 PMs and IMs, respectively, compared with NMs (P < .01 and P < .001). CYP2D6 was of minor or no importance to haloperidol (320 samples) and flupentixol (115 samples). In our data material, the genotype CYP2D6 *1/*41 appears to have a similar impact on dose-adjusted serum concentrations of perphenazine as *1/null (null = variant allele encoding no enzyme function). CONCLUSIONS This study shows that CYP2D6 is important for the metabolism of perphenazine and zuclopenthixol, but not for haloperidol and flupentixol. The CYP2D6*41 allele appears to have a reduced function close to nonfunctional variant alleles.
Collapse
Affiliation(s)
| | - Vigdis Solhaug
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway
| | - Gudrun Høiseth
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.,Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
3
|
Chang FC, Fung VS. Clinical significance of pharmacogenomic studies in tardive dyskinesia associated with patients with psychiatric disorders. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2014; 7:317-28. [PMID: 25378945 PMCID: PMC4207069 DOI: 10.2147/pgpm.s52806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pharmacogenomics is the study of the effects of genetic polymorphisms on medication pharmacokinetics and pharmacodynamics. It offers advantages in predicting drug efficacy and/or toxicity and has already changed clinical practice in many fields of medicine. Tardive dyskinesia (TD) is a movement disorder that rarely remits and poses significant social stigma and physical discomfort for the patient. Pharmacokinetic studies show an association between cytochrome P450 enzyme-determined poor metabolizer status and elevated serum antipsychotic and metabolite levels. However, few prospective studies have shown this to correlate with the occurrence of TD. Many retrospective, case-control and cross-sectional studies have examined the association of cytochrome P450 enzyme, dopamine (receptor, metabolizer and transporter), serotonin (receptor and transporter), and oxidative stress enzyme gene polymorphisms with the occurrence and severity of TD. These studies have produced conflicting and confusing results secondary to heterogeneous inclusion criteria and other patient characteristics that also act as confounding factors. This paper aims to review and summarize the pharmacogenetic findings in antipsychotic-associated TD and assess its clinical significance for psychiatry patients. In addition, we hope to provide insight into areas that need further research.
Collapse
Affiliation(s)
- Florence Cf Chang
- Movement Disorders Unit, Department of Neurology, Westmead Hospital, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Victor Sc Fung
- Movement Disorders Unit, Department of Neurology, Westmead Hospital, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
4
|
Ravyn D, Ravyn V, Lowney R, Nasrallah HA. CYP450 pharmacogenetic treatment strategies for antipsychotics: a review of the evidence. Schizophr Res 2013; 149:1-14. [PMID: 23870808 DOI: 10.1016/j.schres.2013.06.035] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/03/2013] [Accepted: 06/19/2013] [Indexed: 12/21/2022]
Abstract
Although a number of first- and second-generation antipsychotics are available, achieving optimal therapeutic response for patients with schizophrenia can be challenging. The presence of polymorphic alleles for cytochrome P (CYP) 450 may result in lack of expression, altered levels of expression, or altered function of CYP450 enzymes. CYP2D6, CYP1A2, and CYP3A4/5 are major enzymes in the metabolism of antipsychotics and polymorphisms of alleles for these proteins are associated with altered plasma levels. Consequently, standard dosing may result in drug plasma concentrations that are subtherapeutic or toxic in some patients. Patient CYP450 genotype testing can predict altered pharmacokinetics, and is currently available and relatively inexpensive. Evidence-based guidelines provide dose recommendations for some antipsychotics. To date few studies have demonstrated a significant association with genotype-guided antipsychotic use and clinical efficacy. However, many studies have been small, retrospective or cohort designs, and many have not been adequately powered. Numerous studies have shown a significant association between genotype and adverse effects, such as CYP2D6 polymorphisms and tardive dyskinesia. This review summarizes evidence for the role of CYP450 genetic variants in the response to antipsychotic medications and the clinical implications of pharmacogenetics in the management of patients with schizophrenia.
Collapse
Affiliation(s)
- Dana Ravyn
- CMEology, West Hartford, CT, United States
| | | | | | | |
Collapse
|
5
|
Ma JD, Nafziger AN, Bertino JS. Genetic Polymorphisms of Cytochrome P450 Enzymes and the Effect on Interindividual, Pharmacokinetic Variability in Extensive Metabolizers. J Clin Pharmacol 2013; 44:447-56. [PMID: 15102864 DOI: 10.1177/0091270004264642] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Genetic polymorphisms of cytochrome P450 (CYP) enzymes are one of the factors that contribute to the pharmacokinetic (PK) variability of drugs. PK variability is observed in the bimodal distribution between extensive metabolizers (EMs) and poor metabolizers (PMs). PK variability may also exist between individuals genotyped as homozygous EMs and heterozygous EMs. This may carry implications for drug dosing and drug response (e.g., risk of therapeutic failure or drug toxicity). Studies have reported significant PK differences between homozygous and heterozygous EMs. Some literature suggests that this distinction may be of clinical relevance. Due to study design limitations and data that are either sparse or conflicting, generalizations regarding the potential impact of the CYP genotype, within EMs, are difficult. Optimally designed clinical trials are needed. This review evaluates the potential impact of CYP genetic polymorphisms on interindividual PK variability of drugs within an EM population.
Collapse
Affiliation(s)
- Joseph D Ma
- Clinical Pharmacology Research Center, Bassett Healthcare, One Atwell Road, Cooperstown, NY 13326-1394, USA
| | | | | |
Collapse
|
6
|
Brown RW, Maple AM, Perna MK, Sheppard AB, Cope ZA, Kostrzewa RM. Schizophrenia and Substance Abuse Comorbidity: Nicotine Addiction and the Neonatal Quinpirole Model. Dev Neurosci 2012; 34:140-51. [DOI: 10.1159/000338830] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 04/12/2012] [Indexed: 01/06/2023] Open
|
7
|
|
8
|
Zhou SF, Liu JP, Chowbay B. Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 2009; 41:89-295. [PMID: 19514967 DOI: 10.1080/03602530902843483] [Citation(s) in RCA: 502] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pharmacogenetics is the study of how interindividual variations in the DNA sequence of specific genes affect drug response. This article highlights current pharmacogenetic knowledge on important human drug-metabolizing cytochrome P450s (CYPs) to understand the large interindividual variability in drug clearance and responses in clinical practice. The human CYP superfamily contains 57 functional genes and 58 pseudogenes, with members of the 1, 2, and 3 families playing an important role in the metabolism of therapeutic drugs, other xenobiotics, and some endogenous compounds. Polymorphisms in the CYP family may have had the most impact on the fate of therapeutic drugs. CYP2D6, 2C19, and 2C9 polymorphisms account for the most frequent variations in phase I metabolism of drugs, since almost 80% of drugs in use today are metabolized by these enzymes. Approximately 5-14% of Caucasians, 0-5% Africans, and 0-1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant enzyme that demonstrates multiple genetic variants with a potentially functional impact on the efficacy and adverse effects of drugs that are mainly eliminated by this enzyme. Studies into the CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and *3 alleles. Extensive polymorphism also occurs in other CYP genes, such as CYP1A1, 2A6, 2A13, 2C8, 3A4, and 3A5. Since several of these CYPs (e.g., CYP1A1 and 1A2) play a role in the bioactivation of many procarcinogens, polymorphisms of these enzymes may contribute to the variable susceptibility to carcinogenesis. The distribution of the common variant alleles of CYP genes varies among different ethnic populations. Pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and currently available drugs. Further studies are warranted to explore the gene-dose, gene-concentration, and gene-response relationships for these important drug-metabolizing CYPs.
Collapse
Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Bundoora, Victoria, Australia.
| | | | | |
Collapse
|
9
|
Darby JK, Pasta DJ, Wilson MG, Herbert J. Long-Term Therapeutic Drug Monitoring of Risperidone and Olanzapine Identifies Altered Steady-State Pharmacokinetics. Clin Drug Investig 2008; 28:553-64. [DOI: 10.2165/00044011-200828090-00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
10
|
Gardiner SJ, Begg EJ. Pharmacogenetics, drug-metabolizing enzymes, and clinical practice. Pharmacol Rev 2006; 58:521-90. [PMID: 16968950 DOI: 10.1124/pr.58.3.6] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The application of pharmacogenetics holds great promise for individualized therapy. However, it has little clinical reality at present, despite many claims. The main problem is that the evidence base supporting genetic testing before therapy is weak. The pharmacology of the drugs subject to inherited variability in metabolism is often complex. Few have simple or single pathways of elimination. Some have active metabolites or enantiomers with different activities and pathways of elimination. Drug dosing is likely to be influenced only if the aggregate molar activity of all active moieties at the site of action is predictably affected by genotype or phenotype. Variation in drug concentration must be significant enough to provide "signal" over and above normal variation, and there must be a genuine concentration-effect relationship. The therapeutic index of the drug will also influence test utility. After considering all of these factors, the benefits of prospective testing need to be weighed against the costs and against other endpoints of effect. It is not surprising that few drugs satisfy these requirements. Drugs (and enzymes) for which there is a reasonable evidence base supporting genotyping or phenotyping include suxamethonium/mivacurium (butyrylcholinesterase), and azathioprine/6-mercaptopurine (thiopurine methyltransferase). Drugs for which there is a potential case for prospective testing include warfarin (CYP2C9), perhexiline (CYP2D6), and perhaps the proton pump inhibitors (CYP2C19). No other drugs have an evidence base that is sufficient to justify prospective testing at present, although some warrant further evaluation. In this review we summarize the current evidence base for pharmacogenetics in relation to drug-metabolizing enzymes.
Collapse
Affiliation(s)
- Sharon J Gardiner
- Department of Medicine, Christchurch School of Medicine, Private Bag 4345, Christchurch, New Zealand.
| | | |
Collapse
|
11
|
Kroon LA. Drug interactions and smoking: raising awareness for acute and critical care providers. Crit Care Nurs Clin North Am 2006; 18:53-62, xii. [PMID: 16546008 DOI: 10.1016/j.ccell.2005.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Because the prevalence of smoking in the United States remains significantly high, it is important to determine a patient's smoking status and perform a complete medication history to assess for potential drug interactions with smoking. Tobacco smoke can increase the hepatic metabolism and can oppose the pharmacologic effects of certain drugs. This article reviews the clinically significant drug interactions, resulting primarily from the induction of cytochrome P450 enzymes by tobacco smoke, of which all acute and critical care providers need to be aware when making therapeutic decisions and recommendations.
Collapse
Affiliation(s)
- Lisa A Kroon
- Department of Clinical Pharmacy, School of Pharmacy, University of California, San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143, USA.
| |
Collapse
|
12
|
Mulder H, Herder A, Wilmink FW, Tamminga WJ, Belitser SV, Egberts ACG. The impact of Cytochrome P450-2D6 genotype on the use and interpretation of therapeutic drug monitoring in long-stay patients treated with antidepressant and antipsychotic drugs in daily psychiatric practice. Pharmacoepidemiol Drug Saf 2006; 15:107-14. [PMID: 16294366 DOI: 10.1002/pds.1173] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
PURPOSE This retrospective follow-up study investigates whether cytochrome P450-2D6 (CYP2D6) genotype explains variability in plasma concentrations of psychotropic drugs in daily psychiatric practice. METHODS The study population consisted of 62 hospitalised psychiatric patients genotyped for CYP2D6. Primary endpoint was the normalised plasma concentration ratio which was defined as the [measured concentration]/[mean therapeutic concentration] allowing comparison of plasma concentrations of different substrates. Secondary endpoint was a plasma concentration above the therapeutic range. The determinant was CYP2D6 genotype classified as ultrarapid metaboliser (UM), extensive metaboliser (EM), intermediate metaboliser (IM), or poor metaboliser (PM). The relation between CYP2D6 genotype and the normalised plasma concentration ratio was assessed with a linear mixed-effects model after adjustment for the Prescribed Daily Dose (PDD). The risk of having a plasma concentration above the therapeutic range was assessed with a logistic mixed-effects model. RESULTS For antidepressants, CYP2D6 genotype PM (1.68 (95%CI: 1.01-2.28)) and IM (1.09 (95%CI: 0.77-1.29)) were associated with higher normalised plasma concentration ratios of antidepressants compared to EMs (0.56 (95%CI: 0.26-0.74)). In addition, the risk of a plasma concentration above the therapeutic range was increased for PMs (OR 33.1 (95%CI: 2.0-544.6)) and IMs (OR 8.2 (95%CI: 1.1-60.3)) relative to EMs using antidepressants. CYP2D6 genotype could not clearly explain variability in plasma concentrations of antipsychotics possibly due to a low frequency of therapeutic drug monitoring (TDM) in antipsychotics primarily metabolised by CYP2D6 in daily psychiatric practice. CONCLUSIONS CYP2D6 genotype contributes to clinically relevant variability in plasma concentrations of antidepressants but probably not antipsychotics in daily clinical practice.
Collapse
Affiliation(s)
- Hans Mulder
- Department of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, The Netherlands
| | | | | | | | | | | |
Collapse
|
13
|
Abstract
In normal subjects after a single oral dose, haloperidol half-life has been reported to range 14.5-36.7 hours (or up to 1.5 days). After chronic administration, half-lives of up to 21 days have been reported. The objective of this study was to evaluate specific factors that might account for differences in haloperidol half-life in patients taking haloperidol chronically, including gender, age, weight, race, CYP2D6 and CYP3A5 genotypes, comedication, and smoking.Thirty-one patients were administered haloperidol for 4 weeks followed by a 1-week washout before administration of clozapine. Haloperidol plasma levels were measured weekly for at least 2 months after discontinuation. The geometric mean for haloperidol half-life and detectable levels duration were 3.9 and 13.8 days, respectively. Within 31 subjects, 58% (18/31) had half-lives <3 days (1.2-2.3 days) and 42% (13/31) had half-lives > or =3 days. Two of 3 patients with half-lives longer than 30 days (720 hours) and levels detectable >2 months had received haloperidol decanoate. Five patients who received haloperidol decanoate in the prior year were excluded from a comparison between patients with long haloperidol half-lives (> or =3 days, n = 10) and patients with short half-lives (<3 days, n = 16). The only significant difference between the two groups was that African-Americans (n = 4) were all found to have a long haloperidol half-life (P = 0.014). CYP3A5 genotype did not appear to influence haloperidol half-life but the two CYP2D6 poor metabolizer had half-lives > or =3 days. This study suggests that haloperidol half-life following repeated drug administration is substantially more prolonged than what has been observed after acute haloperidol administration.
Collapse
Affiliation(s)
- Jose de Leon
- Mental Health Research Center at Eastern State Hospital, Lexington, KY, USA.
| | | | | | | | | | | |
Collapse
|
14
|
Ohara K, Tanabu S, Yoshida K, Ishibashi K, Ikemoto K, Shibuya H. Effects of smoking and cytochrome P450 2D6*10 allele on the plasma haloperidol concentration/dose ratio. Prog Neuropsychopharmacol Biol Psychiatry 2003; 27:945-9. [PMID: 14499311 DOI: 10.1016/s0278-5846(03)00154-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study was carried out to evaluate the influence of CYP2D6 polymorphism and smoking on the plasma clearance of haloperidol (HAL) levels, accounting for the antipsychotic dose, body weight, and coadministration of other drugs. METHODS Subjects were 110 Japanese patients (66 male, 44 female) diagnosed with schizophrenia, dementia, or mood disorder and treated orally with HAL. Venous blood was obtained from each patient to determine the HAL concentration/dose (C/D) ratio (plasma concentration of HAL divided by the daily dose of HAL per body weight) and for CYP2D6 genotyping. RESULTS There was no significant difference in the HAL C/D ratio between nonsmokers and smokers. In patients with a non-2D6*10 homozygous genotype, smokers had a significantly lower HAL C/D ratio than nonsmokers, whereas smokers with a 2D6*10 homozygous genotype had a significantly higher HAL C/D ratio than those with a non-2D6*10 homozygous genotype. CONCLUSION Our results suggest that the effect of smoking on the HAL C/D ratio depends on the CYP2D6*10 genotype.
Collapse
Affiliation(s)
- Koichi Ohara
- Clinical Research Institute, National Minami Hanamaki Hospital, Hanamaki, Iwate, Japan.
| | | | | | | | | | | |
Collapse
|
15
|
Ellingrod VL, Schultz SK, Arndt S. Abnormal movements and tardive dyskinesia in smokers and nonsmokers with schizophrenia genotyped for cytochrome P450 2D6. Pharmacotherapy 2002; 22:1416-9. [PMID: 12432967 DOI: 10.1592/phco.22.16.1416.33700] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To investigate the relationships between cytochrome P450 (CYP) 2D6 genotype, antipsychotic drug exposure, abnormal movements and tardive dyskinesia, and cigarette smoking. DESIGN Prospective, longitudinal study. SETTING University mental health research center. PATIENTS Thirty-seven patients with schizophrenia. INTERVENTION Patients were genotyped for CYP2D6*1, *3, and *4 alleles, and data were collected on their psychiatric symptoms, cigarette smoking status, and antipsychotic drug exposure. Abnormal movements were measured using the Abnormal Involuntary Movement Scale (AIMS). Presence of tardive dyskinesia was also evaluated. MEASUREMENTS AND MAIN RESULTS A linear regression model used the AIMS scores as the dependent variable, and genotype, sex, smoking status, and antipsychotic drug exposure as independent variables. Antipsychotic drug exposure, genotype, and cigarette smoking interaction was significant (p<0.0212) for patients with the CYP2D6*1/*3, *4 genotype. Seventy-eight percent of smokers with the CYP2D6*1/*3, *4 genotype had tardive dyskinesia compared with 20-33% of patients in other groups. CONCLUSION Patients with a CYP2D6*3 or *4 allele may shunt antipsychotic metabolism through other pathways that are induced by cigarette smoke. This induction may result in formation of neurotoxic metabolites, leading to increased AIMS scores and a higher frequency of tardive dyskinesia compared with patients without these alleles.
Collapse
|
16
|
Dahl ML. Cytochrome p450 phenotyping/genotyping in patients receiving antipsychotics: useful aid to prescribing? Clin Pharmacokinet 2002; 41:453-70. [PMID: 12083975 DOI: 10.2165/00003088-200241070-00001] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many antipsychotics, including perphenazine, zuclopenthixol, thioridazine, haloperidol and risperidone, are metabolised to a significant extent by the polymorphic cytochrome P450 (CYP) 2D6, which shows large interindividual variation in activity. Significant relationships between CYP2D6 genotype and steady-state concentrations have been reported for perphenazine, zuclopenthixol, risperidone and haloperidol when used in monotherapy. Other CYPs, especially CYP1A2 and CYP3A4, also contribute to the interindividual variability in the kinetics of antipsychotics and the occurrence of drug interactions. For many antipsychotics, the role of the different CYPs at therapeutic drug concentrations remains to be clarified. Some studies have suggested that poor metabolisers for CYP2D6 would be more prone to oversedation and possibly parkinsonism during treatment with classical antipsychotics, whereas other, mostly retrospective, studies have been negative or inconclusive. For the newer antipsychotics, such data are lacking. Whether phenotyping or genotyping for CYP2D6 or other CYPs can be used to predict an optimal dose range has not been studied so far. Genotyping or phenotyping can today be recommended as a complement to plasma concentration determination when aberrant metabolic capacity (poor or ultrarapid) of CYP2D6 substrates is suspected. The current rapid developments in molecular genetic methodology and pharmacogenetic knowledge can in the near future be expected to provide new tools for prediction of the activity of the various drug-metabolising enzymes. Further prospective clinical studies in well-defined patient populations and with adequate evaluation of therapeutic and adverse effects are required to establish the potential of pharmacogenetic testing in clinical psychiatry.
Collapse
Affiliation(s)
- Marja-Liisa Dahl
- Department of Medical Sciences, Clinical Pharmacology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
| |
Collapse
|
17
|
Abstract
Antipsychotic drugs are used for the treatment of schizophrenia and other related psychotic disorders. The antipsychotics currently available include older or classical compounds and newer or atypical agents. Most antipsychotic drugs are highly lipophilic compounds and undergo extensive metabolism by cytochrome P450 (CYP) enzymes in order to be excreted. There is a wide interindividual variability in the biotransformation of antipsychotic drugs, resulting in pronounced differences in steady-state plasma concentrations and, possibly, in therapeutic and toxic effects, during treatment with fixed doses. Many classical and some newer antipsychotics are metabolized to a significant extent by the polymorphic CYP2D6, which shows large interindividual variation in activity. Other CYPs, especially CYP1A2 and CYP3A4, also contribute to the interindividual variability in the kinetics of antipsychotics and occurrence of drug interactions. No relationship between CYP2D6 genotype or activity and therapeutic effects of classical antipsychotic drugs has been found in the few studies performed. On the other hand, some investigations suggest that poor metabolizers (PMs) of CYP2D6 would be more prone to over-sedation and, possibly, Parkinsonism during treatment with classical antipsychotics, while other studies, mostly retrospective, have been negative or inconclusive. For the newer antipsychotics, such data are lacking. To date, CYP2D6 phenotyping and genotyping appear, therefore, to be clinically useful for dose predicting only in special cases and for a limited number of antipsychotics, while their usefulness in predicting clinical effects must be further explored.
Collapse
Affiliation(s)
- Maria Gabriella Scordo
- Section of Pharmacology, Department of Clinical and Experimental Medicine and Pharmacology, University of Messina, Via Consolare Valeria Gazzi, I 98125 Messina, Italy.
| | | |
Collapse
|
18
|
Fukuda R. Factors affecting serum haloperidol level assessed by longitudinal therapeutic monitoring. Prog Neuropsychopharmacol Biol Psychiatry 2000; 24:1299-318. [PMID: 11125855 DOI: 10.1016/s0278-5846(00)00142-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1. Since the development of a kit for the assay of haloperidol by enzyme immunoassay, therapeutic monitoring of haloperidol has been utilised in Japan for several years. By retrospectively analysing the accumulated data, this study was carried out to investigate the factors affecting haloperidol level. Especially, the effects of enzyme-inducing comedications were analysed in relation to serum gamma-glutamyltransferase (GGT) level, which has been measured simultaneously with haloperidol. Serum haloperidol level measurements were obtained from medical records of inpatients on multiple medications (n = 102). For each subject, average haloperidol level was computed during the same prescription and doses. The effects of age, sex, smoking status, and the coadministration of carbamazepine and barbiturates (including phenobarbital, amobarbital and pentobarbital) were analysed using correlation, between-group comparison and multiple regression analysis. Separately, the effect of comedications on haloperidol and GGT levels were analysed individually in a small number of patients (n = 5) who had received those comedications intermittently. Significant lowering of serum haloperidol level by the coadministration of carbamazepine and/or barbiturates was observed. The coadministration was also correlated with the elevated GGT level in between-group comparison. In the separate analysis, the change in haloperidol level was correlated with the change in GGT level in some individuals but not in others. None of the other clinical factors investigated in the study showed significant effect on haloperidol level. This study suggests that the lowering of haloperidol level and the elevation of GGT level may often occur coincidentally by the coadministration of enzyme-inducing drugs. However, whether there is a causal relationship between these phenomena and whether elevated serum GGT level could serve as a clinically useful marker need to be clarified by further basic pharmacological research.
Collapse
Affiliation(s)
- R Fukuda
- Department of Psychiatry, Teikyo University School of Medicine, Tokyo, Japan.
| |
Collapse
|