1
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Tamayo-Trujillo R, Ibarra-Castillo R, Laso-Bayas JL, Guevara-Ramirez P, Cadena-Ullauri S, Paz-Cruz E, Ruiz-Pozo VA, Doménech N, Ibarra-Rodríguez AA, Zambrano AK. Identifying genomic variant associated with long QT syndrome type 2 in an ecuadorian mestizo individual: a case report. Front Genet 2024; 15:1395012. [PMID: 38957812 PMCID: PMC11217513 DOI: 10.3389/fgene.2024.1395012] [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: 03/02/2024] [Accepted: 05/27/2024] [Indexed: 07/04/2024] Open
Abstract
Introduction Long QT syndrome (LQTS) is an autosomal dominant inherited cardiac condition characterized by a QT interval prolongation and risk of sudden death. There are 17 subtypes of this syndrome associated with genetic variants in 11 genes. The second most common is type 2, caused by a mutation in the KCNH2 gene, which is part of the potassium channel and influences the final repolarization of the ventricular action potential. This case report presents an Ecuadorian teen with congenital Long QT Syndrome type 2 (OMIM ID: 613688), from a family without cardiac diseases or sudden cardiac death backgrounds. Case presentation A 14-year-old girl with syncope, normal echocardiogram, and an irregular electrocardiogram was diagnosed with LQTS. Moreover, by performing Next-Generation Sequencing, a pathogenic variant in the KCNH2 gene p.(Ala614Val) (ClinVar ID: VCV000029777.14) associated with LQTS type 2, and two variants of uncertain significance in the AKAP9 p.(Arg1654GlyfsTer23) (rs779447911), and TTN p. (Arg34653Cys) (ClinVar ID: VCV001475968.4) genes were identified. Furthermore, ancestry analysis showed a mainly Native American proportion. Conclusion Based on the genomic results, the patient was identified to have a high-risk profile, and an implantable cardioverter defibrillator was selected as the best treatment option, highlighting the importance of including both the clinical and genomics aspects for an integral diagnosis.
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Affiliation(s)
- Rafael Tamayo-Trujillo
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
| | | | | | - Patricia Guevara-Ramirez
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
| | - Santiago Cadena-Ullauri
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
| | - Elius Paz-Cruz
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
| | - Viviana A. Ruiz-Pozo
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
| | - Nieves Doménech
- Instituto de Investigación Biomédica de A Coruña (INIBIC)-CIBERCV, Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas. Universidad da Coruña (UDC), Coruña, Spain
| | - Adriana Alexandra Ibarra-Rodríguez
- Grupo de investigación identificación Genética-IdentiGEN, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Antioquia, Medellín, Colombia
| | - Ana Karina Zambrano
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito, Ecuador
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2
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Afzal MA, Khalid N, Abdullah M, Ul-Haiy A, Michael P. Hydroxyzine-Induced Torsade De Pointes: A Case Report and a Literature Review. Cureus 2023; 15:e41588. [PMID: 37559846 PMCID: PMC10407684 DOI: 10.7759/cureus.41588] [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] [Accepted: 07/08/2023] [Indexed: 08/11/2023] Open
Abstract
Hydroxyzine is an H1-receptor antagonist used for managing allergies, anxiety, opioid withdrawal, and insomnia. An adverse effect of hydroxyzine, QT prolongation, may lead to torsade de pointes (TdP). Our case report and literature review highlight the risk of TdP with hydroxyzine use. Our patient, a 58-year-old male with an implantable cardioverter defibrillator (ICD) and a history of polysubstance abuse presented with chest pain and shortness of breath. During the admission, the patient started experiencing symptoms of opioid withdrawal, which were refractory to buprenorphine. Hydroxyzine 50 mg was administered as recommended for symptomatic anxiety relief. Overnight the patient developed TdP, which was managed by MgSO4, amiodarone, and lidocaine, but did not resolve the arrhythmia. The patient was sedated and intubated, which led to the episode's resolution. This case report and literature review underscore the importance of cautious prescribing practices for hydroxyzine and other QT-prolonging drugs to prevent TdP. Healthcare providers should conduct personalized risk assessments, monitor electrolyte levels, and perform regular electrocardiograms. Administering the lowest effective dose, avoiding drug interactions, and exercising caution in patients with underlying repolarization abnormalities or a history of TdP are crucial. These measures help minimize the risk of TdP associated with low-dose hydroxyzine therapy.
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Affiliation(s)
| | - Noman Khalid
- Internal Medicine, St. Joseph's University Medical Center, Paterson, USA
| | - Muhammad Abdullah
- Public Health and Community Medicine, Shaikh Khalifa Bin Zayed Al-Nahyan Medical and Dental College, Shaikh Zayed Federal Postgraduate Medical Institute at Shaikh Zayed Medical Complex, Lahore, PAK
| | - Ata Ul-Haiy
- Internal Medicine, Mayo Hospital, Kind Edward Medical University, Lahore, PAK
| | - Patrick Michael
- Internal Medicine, St. Joseph's University Medical Center, Paterson, USA
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3
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Hashimoto K, Ide S, Arata M, Nakata A, Ito A, Ito TK, Kudo N, Lin B, Nunomura K, Tsuganezawa K, Yoshida M, Nagaoka Y, Sumiyoshi T. Discovery of Benzylpiperazine Derivatives as CNS-Penetrant and Selective Histone Deacetylase 6 Inhibitors. ACS Med Chem Lett 2022; 13:1077-1082. [DOI: 10.1021/acsmedchemlett.2c00081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Kosuke Hashimoto
- Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
| | - Soichiro Ide
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Mayumi Arata
- Seed Compounds Exploratory Unit for Drug Discovery Platform, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akiko Nakata
- Seed Compounds Exploratory Unit for Drug Discovery Platform, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiro Ito
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Takashi K. Ito
- Seed Compounds Exploratory Unit for Drug Discovery Platform, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Norio Kudo
- Seed Compounds Exploratory Unit for Drug Discovery Platform, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Bangzhong Lin
- Center for Supporting Drug Discovery and Life Science Research, Graduate School of Pharmaceutical Science, Osaka University, Yamadaoka 1-6, Suita, Osaka 565-0871, Japan
| | - Kazuto Nunomura
- Center for Supporting Drug Discovery and Life Science Research, Graduate School of Pharmaceutical Science, Osaka University, Yamadaoka 1-6, Suita, Osaka 565-0871, Japan
| | - Keiko Tsuganezawa
- Drug Discovery Structural Biology Platform Unit, RIKEN Center for Biosystems Dynamic Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Minoru Yoshida
- Seed Compounds Exploratory Unit for Drug Discovery Platform, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuo Nagaoka
- Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
| | - Takaaki Sumiyoshi
- Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan
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4
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Li L, Liu R, Peng C, Chen X, Li J. Pharmacogenomics for the efficacy and side effects of antihistamines. Exp Dermatol 2022; 31:993-1004. [PMID: 35538735 DOI: 10.1111/exd.14602] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/01/2022] [Accepted: 05/09/2022] [Indexed: 11/27/2022]
Abstract
Antihistamines, especially H1 antihistamines, are widely used in the treatment of allergic diseases such as urticaria and allergic rhinitis, mainly for reversing elevated histamine and anti-allergic effects. Antihistamines are generally safe, but some patients experience adverse reactions, such as cardiotoxicity, central inhibition, and anticholinergic effects. There are also individual differences in antihistamine efficacy in clinical practice. The concept of individualized medicine has been deeply rooted in people's minds since it was put forward. Pharmacogenomics is the study of the role of inheritance in individual variations in drug response. In recent decades, pharmacogenomics has been developing rapidly, which provides new ideas for individualized medicine. Polymorphisms in the genes encoding metabolic enzymes, transporters, and target receptors have been shown to affect the efficacy of antihistamines. In addition, recent evidence suggests that gene polymorphisms influence urticaria susceptibility and antihistamine therapy. Here, we summarize current reports in this area, aiming to contribute to future research in antihistamines and clinical guidance for antihistamines use in individualized medicine.
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Affiliation(s)
- Liqiao Li
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Runqiu Liu
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Cong Peng
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiang Chen
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jie Li
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
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5
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Simpson KE, Venkateshappa R, Pang ZK, Faizi S, Tibbits GF, Claydon TW. Utility of Zebrafish Models of Acquired and Inherited Long QT Syndrome. Front Physiol 2021; 11:624129. [PMID: 33519527 PMCID: PMC7844309 DOI: 10.3389/fphys.2020.624129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/21/2020] [Indexed: 01/12/2023] Open
Abstract
Long-QT Syndrome (LQTS) is a cardiac electrical disorder, distinguished by irregular heart rates and sudden death. Accounting for ∼40% of cases, LQTS Type 2 (LQTS2), is caused by defects in the Kv11.1 (hERG) potassium channel that is critical for cardiac repolarization. Drug block of hERG channels or dysfunctional channel variants can result in acquired or inherited LQTS2, respectively, which are typified by delayed repolarization and predisposition to lethal arrhythmia. As such, there is significant interest in clear identification of drugs and channel variants that produce clinically meaningful perturbation of hERG channel function. While toxicological screening of hERG channels, and phenotypic assessment of inherited channel variants in heterologous systems is now commonplace, affordable, efficient, and insightful whole organ models for acquired and inherited LQTS2 are lacking. Recent work has shown that zebrafish provide a viable in vivo or whole organ model of cardiac electrophysiology. Characterization of cardiac ion currents and toxicological screening work in intact embryos, as well as adult whole hearts, has demonstrated the utility of the zebrafish model to contribute to the development of therapeutics that lack hERG-blocking off-target effects. Moreover, forward and reverse genetic approaches show zebrafish as a tractable model in which LQTS2 can be studied. With the development of new tools and technologies, zebrafish lines carrying precise channel variants associated with LQTS2 have recently begun to be generated and explored. In this review, we discuss the present knowledge and questions raised related to the use of zebrafish as models of acquired and inherited LQTS2. We focus discussion, in particular, on developments in precise gene-editing approaches in zebrafish to create whole heart inherited LQTS2 models and evidence that zebrafish hearts can be used to study arrhythmogenicity and to identify potential anti-arrhythmic compounds.
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Affiliation(s)
- Kyle E. Simpson
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Ravichandra Venkateshappa
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Zhao Kai Pang
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Shoaib Faizi
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Glen F. Tibbits
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Cardiovascular Science, British Columbia Children’s Hospital, Vancouver, BC, Canada
| | - Tom W. Claydon
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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6
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Dong X, Liu Y, Niu H, Wang G, Dong L, Zou A, Wang K. Electrophysiological characterization of a small molecule activator on human ether-a-go-go-related gene (hERG) potassium channel. J Pharmacol Sci 2019; 140:284-290. [DOI: 10.1016/j.jphs.2019.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 07/30/2019] [Accepted: 08/01/2019] [Indexed: 02/02/2023] Open
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7
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Yasumasu T. Momentary giant T-waves hint the genesis of the electrocardiographic T-wave in human. J Arrhythm 2018; 34:640-642. [PMID: 30555608 PMCID: PMC6288603 DOI: 10.1002/joa3.12105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/20/2018] [Accepted: 07/10/2018] [Indexed: 11/16/2022] Open
Abstract
T-wave morphology changes are linked to dispersion of ventricular repolarization. I encountered an 80-year-old man on hemodialysis manifesting momentary giant T-waves and QT prolongation on the 12-lead electrocardiogram, soon after initiating mechanical ventilation because of hypercapnic respiratory failure. A computed tomography of the brain showed no acute cerebrovascular accidents. An echocardiogram showed no left ventricular asynergy. Mechanisms that may be responsible for this phenomenon are discussed. Interpreting the giant T-waves with the concept of the three bipolar limb lead vectors, the Einthoven's triangle leads to recognize origin of the electrocardiographic T-wave.
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Affiliation(s)
- Tomiya Yasumasu
- Department of CardiologySaiseikai Yahata General HospitalKitakyushuJapan
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8
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Anesthesia for Dental Procedures. Anesthesiology 2018. [DOI: 10.1007/978-3-319-74766-8_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Poluzzi E, Diemberger I, De Ridder M, Koci A, Clo M, Oteri A, Pecchioli S, Bezemer I, Schink T, Pilgaard Ulrichsen S, Boriani G, Sturkenboom MCJ, De Ponti F, Trifirò G. Use of antihistamines and risk of ventricular tachyarrhythmia: a nested case-control study in five European countries from the ARITMO project. Eur J Clin Pharmacol 2017; 73:1499-1510. [PMID: 28831527 DOI: 10.1007/s00228-017-2317-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 08/03/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE After regulatory restrictions for terfenadine and astemizole in '90s, only scarce evidence on proarrhythmic potential of antihistamines has been published. We evaluate the risk of ventricular tachyarrhythmia (VA) related to the use of individual antihistamines. METHODS A matched case-control study nested in a cohort of new users of antihistamines was conducted within the EU-funded ARITMO project. Data on 1997-2010 were retrieved from seven healthcare databases: AARHUS (Denmark), GEPARD (Germany), HSD and ERD (Italy), PHARMO and IPCI (Netherlands) and THIN (UK). Cases of VA were selected and up to 100 controls were matched to each case. The odds ratio (OR) of current use for individual antihistamines (AHs) was estimated using conditional logistic regression. RESULTS For agents largely used to prevent allergic symptoms, such as cetirizine, levocetirizine, loratadine, desloratadine and fexofenadine, we found no VA risk. A statistically significant, increased risk of VA was found only for current use of cyclizine in the pooled analysis (ORadj, 5.3; 3.6-7.6) and in THIN (ORadj, 5.3; 95% CI, 3.7-7.6), for dimetindene in GEPARD (ORadj, 3.9; 1.1-14.7) and for ebastine in GEPARD (ORadj, 3.3; 1.1-10.8) and PHARMO (ORadj, 4.6; 1.3-16.2). CONCLUSIONS The risk of VA associated with a few specific antihistamines could be ascribable to heterogeneity in pattern of use or in receptor binding profile.
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Affiliation(s)
- Elisabetta Poluzzi
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
| | - I Diemberger
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - M De Ridder
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands
| | - A Koci
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - M Clo
- Regione Emilia Romagna Health Authority, Bologna, Italy
| | - A Oteri
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands.,Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
| | - S Pecchioli
- Health Search, Italian College of General Practitioners, Florence, Italy.,Regional Agency for Healthcare Services of Tuscany, Florence, Italy
| | - I Bezemer
- PHARMO Institute for Drug Outcomes Research, Utrecht, Netherlands
| | - T Schink
- Leibniz Institute for Epidemiology and Prevention Research - BIPS, Bremen, Germany
| | - S Pilgaard Ulrichsen
- Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| | - G Boriani
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.,Cardiology Division, Department of Diagnostics, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - M C J Sturkenboom
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands
| | - F De Ponti
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - G Trifirò
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands.,Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
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10
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Schlit AF, Delaunois A, Colomar A, Claudio B, Cariolato L, Boev R, Valentin JP, Peters C, Sloan VS, Bentz JWG. Risk of QT prolongation and torsade de pointes associated with exposure to hydroxyzine: re-evaluation of an established drug. Pharmacol Res Perspect 2017; 5:e00309. [PMID: 28480041 PMCID: PMC5415947 DOI: 10.1002/prp2.309] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 01/10/2023] Open
Abstract
Several noncardiac drugs have been linked to cardiac safety concerns, highlighting the importance of post‐marketing surveillance and continued evaluation of the benefit‐risk of long‐established drugs. Here, we examine the risk of QT prolongation and/or torsade de pointes (TdP) associated with the use of hydroxyzine, a first generation sedating antihistamine. We have used a combined methodological approach to re‐evaluate the cardiac safety profile of hydroxyzine, including: (1) a full review of the sponsor pharmacovigilance safety database to examine real‐world data on the risk of QT prolongation and/or TdP associated with hydroxyzine use and (2) nonclinical electrophysiological studies to examine concentration‐dependent effects of hydroxyzine on a range of human cardiac ion channels. Based on a review of pharmacovigilance data between 14th December 1955 and 1st August 2016, we identified 59 reports of QT prolongation and/or TdP potentially linked to hydroxyzine use. Aside from intentional overdose, all cases involved underlying medical conditions or concomitant medications that constituted at least 1 additional risk factor for such events. The combination of cardiovascular disorders plus concomitant treatment of drugs known to induce arrhythmia was identified as the greatest combined risk factor. Parallel patch‐clamp studies demonstrated hydroxyzine concentration‐dependent inhibition of several human cardiac ion channels, including the ether‐a‐go‐go‐related gene (hERG) potassium ion channels. Results from this analysis support the listing of hydroxyzine as a drug with “conditional risk of TdP” and are in line with recommendations to limit hydroxyzine use in patients with known underlying risk factors for QT prolongation and/or TdP.
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Affiliation(s)
| | | | - Aurore Colomar
- UCB Pharma Brussels Belgium.,Present address: Aurore Colomar, Université de Mons Mons Belgium
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11
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Han SN, Jing Y, Yang LL, Zhang Z, Zhang LR. Propofol inhibits hERG K + channels and enhances the inhibition effects on its mutations in HEK293 cells. Eur J Pharmacol 2016; 791:168-178. [PMID: 27575519 DOI: 10.1016/j.ejphar.2016.08.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/12/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022]
Abstract
QT interval prolongation, a potential risk for arrhythmias, may result from gene polymorphisms relevant to cardiomyocyte repolarization. Another noted cause of QT interval prolongation is the administration of chemical compounds such as anesthetics, which may affect a specific type of cardiac K+ channel encoded by the human ether-a-go-go-related gene (hERG). hERG K+ current was recorded using whole-cell patch clamp in human embryonic kidney (HEK293) cells expressing wild type (WT) or mutated hERG channels. Expression of hERG K+ channel proteins was evaluated using western blot and confirmed by fluorescent staining and imaging. Computational modeling was adopted to identify the possible binding site(s) of propofol with hERG K+ channels. Propofol had a significant inhibitory effect on WT hERG K+ currents in a concentration-dependent manner, with a half-maximal inhibitory concentration (IC50) of 60.9±6.4μM. Mutations in drug-binding sites (Y652A or F656C) of the hERG channel were found to attenuate hERG current blockage by propofol. However, propofol did not inhibit the trafficking of hERG protein to the cell membrane. Meanwhile, for the three selective hERG K+ channel mutant heterozygotes WT/Q738X-hERG, WT/A422T-hERG, and WT/H562P-hERG, the IC50 of propofol was calculated as 14.2±2.8μM, 3.3±1.2μM, and 5.9±1.9μM, respectively, which were much lower than that for the wild type. These findings indicate that propofol may potentially increase QT interval prolongation risk in patients via direct inhibition of the hERG K+ channel, especially in those with other concurrent triggering factors such as hERG gene mutations.
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Affiliation(s)
- Sheng-Na Han
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Ying Jing
- Department of Physiology and Neurobiology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Lin-Lin Yang
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China; Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhao Zhang
- Jiangsu Key Laboratory for Molecular & Medical Biotechnology, College of Life Science in Nanjing Normal University, Nanjing 210046, China.
| | - Li-Rong Zhang
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China.
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12
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Mahati E, Li P, Kurata Y, Maharani N, Ikeda N, Sakata S, Ogura K, Miake J, Aiba T, Shimizu W, Nakasone N, Ninomiya H, Higaki K, Yamamoto K, Nakai A, Shirayoshi Y, Hisatome I. M3 Muscarinic Receptor Signaling Stabilizes a Novel Mutant Human Ether-a-Go-Go-Related Gene Channel Protein via Phosphorylation of Heat Shock Factor 1 in Transfected Cells. Circ J 2016; 80:2443-2452. [PMID: 27803431 DOI: 10.1253/circj.cj-16-0712] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Endang Mahati
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Diponegoro University
| | - Peili Li
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
| | | | - Nani Maharani
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Diponegoro University
- Center for Biomedical Research (CEBIOR), Faculty of Medicine, Diponegoro University
| | - Nobuhito Ikeda
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
| | - Shinji Sakata
- Department of Pediatrics, Faculty of Medicine, Tottori University
| | - Kazuyoshi Ogura
- Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University
| | - Junichiro Miake
- Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Wataru Shimizu
- Division of Cardiology and Regenerative Medicine, Nippon Medical School
| | - Naoe Nakasone
- Department of Biological Regulation, Faculty of Medicine, Tottori University
| | - Haruaki Ninomiya
- Department of Biological Regulation, Faculty of Medicine, Tottori University
| | - Katsumi Higaki
- Division of Functional Genomics, Research Center for Bioscience and Technology, Tottori University
| | - Kazuhiro Yamamoto
- Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University
| | - Akira Nakai
- Department of Biochemistry and Molecular Biology, Yamaguchi University School of Medicine
| | - Yasuaki Shirayoshi
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
| | - Ichiro Hisatome
- Division of Regenerative Medicine and Therapeutics, Department of Genetic Medicine and Regenerative Therapeutics, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science
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Briône W, Brekelmans M, Eijndhoven FV, Schenkel E, Noij T. Development and validation of a method for the analysis of hydroxyzine hydrochloride in extracellular solution used in in vitro preclinical safety studies. J Pharm Biomed Anal 2015; 115:69-73. [PMID: 26163869 DOI: 10.1016/j.jpba.2015.06.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 11/19/2022]
Abstract
In the process of drug development, preclinical safety studies are to be performed that require the analysis of the compound at very low concentrations with high demands on the performance of the analytical methods. In the current study, a UPLC-MS/MS method was developed and validated to quantify hydroxyzine hydrochloride in an extracellular solution used in a hERG assay in concentrations ranging from 0.01 to 10μM (4.5ng/ml-4.5μg/ml). Chromatographic separation was achieved isocratically on an Acquity BEH C18 analytical column. The assay was validated at concentrations of 0.11-1.1ng/ml in end solution for hydroxyzine hydrochloride. Linearity was demonstrated over the range of concentrations of 0.06-0.17ng/ml and over the range of concentrations of 0.6-1.7ng/ml in end solution with the coefficient of correlation r>0.99. Accuracy of the achieved concentration, intra-run, and inter-run precision of the method were well within the acceptance criteria (being mean recovery of 80-120% and relative standard deviation ≤10.0%). The limit of quantification in extracellular solution was 0.09ng/ml. Hydroxyzine hydrochloride in extracellular solution proved to be stable when stored in the fridge at 4-8°C for at least 37 days, at room temperature for at least 16 days and at +35°C for at least 16 days. The analytical method was successfully applied in hERG assay.
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Affiliation(s)
- Willy Briône
- UCB Pharma S.A., Chemin du Foriest, 1420 Braine L'Alleud, Belgium.
| | - Mari Brekelmans
- WIL Research Europe B.V., Hambakenwetering 7, 5231 DD 's-Hertogenbosch, The Netherlands
| | - Freek van Eijndhoven
- WIL Research Europe B.V., Hambakenwetering 7, 5231 DD 's-Hertogenbosch, The Netherlands
| | - Eric Schenkel
- UCB Pharma S.A., Chemin du Foriest, 1420 Braine L'Alleud, Belgium
| | - Theo Noij
- WIL Research Europe B.V., Hambakenwetering 7, 5231 DD 's-Hertogenbosch, The Netherlands
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Kubo T, Ding WG, Toyoda F, Fujii Y, Omatsu-Kanbe M, Matsuura H. Phosphatidylinositol4-phosphate 5-kinase prevents the decrease in the HERG potassium current induced by Gq protein-coupled receptor stimulation. J Pharmacol Sci 2015; 127:127-34. [PMID: 25704028 DOI: 10.1016/j.jphs.2014.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022] Open
Abstract
The human ether-a-go-go-related gene (HERG) potassium current (IHERG) has been shown to decrease in amplitude following stimulation with Gq protein-coupled receptors (GqRs), such as α1-adrenergic and M1-muscarinic receptors (α1R and M1R, respectively), at least partly via the reduction of membrane phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). The present study was designed to investigate the modulation of HERG channels by PI(4,5)P2 and phosphatidylinositol4-phosphate 5-kinase (PI(4)P5-K), a synthetic enzyme of PI(4,5)P2. Whole-cell patch-clamp recordings were used to examine the activity of HERG channels expressed heterologously in Chinese Hamster Ovary cells. The stimulation of α1R with phenylephrine or M1R with acetylcholine decreased the amplitude of IHERG accompanied by a significant acceleration of deactivation kinetics and the effects on IHERG were significantly attenuated in cells expressing PI(4)P5-K. The density of IHERG in cells expressing GqRs alone was significantly increased by the coexpression of PI(4)P5-K without significant differences in the voltage dependence of activation and deactivation kinetics. The kinase-deficient substitution mutant, PI(4)P5-K-K138A did not have these counteracting effects on the change in IHERG by M1R stimulation. These results suggest that the current density of IHERG is closely dependent on the membrane PI(4,5)P2 level, which is regulated by PI(4)P5-K and GqRs and that replenishing PI(4,5)P2 by PI(4)P5-K recovers IHERG.
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Affiliation(s)
- Taeko Kubo
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan; Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga 520-2192, Japan; Preclinical Research Laboratories, Sumitomo Dainippon Pharma Co., Ltd, Osaka 554-0022, Japan
| | - Wei-Guang Ding
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Futoshi Toyoda
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Yusuke Fujii
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan; Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Mariko Omatsu-Kanbe
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Hiroshi Matsuura
- Department of Physiology, Shiga University of Medical Science, Shiga 520-2192, Japan.
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Vigne J, Alexandre J, Fobe F, Milliez P, Loilier M, Fedrizzi S, Coquerel A. QT prolongation induced by hydroxyzine: a pharmacovigilance case report. Eur J Clin Pharmacol 2015; 71:379-81. [PMID: 25622983 DOI: 10.1007/s00228-014-1804-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 12/29/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Jonathan Vigne
- Department of Pharmacology and Pharmacovigilance, CHU de Caen, Caen, 14032, France
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Yu CC, Ai T, Weiss JN, Chen PS. Apamin does not inhibit human cardiac Na+ current, L-type Ca2+ current or other major K+ currents. PLoS One 2014; 9:e96691. [PMID: 24798465 PMCID: PMC4010514 DOI: 10.1371/journal.pone.0096691] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 04/10/2014] [Indexed: 12/03/2022] Open
Abstract
Background Apamin is commonly used as a small-conductance Ca2+-activated K+ (SK) current inhibitor. However, the specificity of apamin in cardiac tissues remains unclear. Objective To test the hypothesis that apamin does not inhibit any major cardiac ion currents. Methods We studied human embryonic kidney (HEK) 293 cells that expressed human voltage-gated Na+, K+ and Ca2+ currents and isolated rabbit ventricular myocytes. Whole-cell patch clamp techniques were used to determine ionic current densities before and after apamin administration. Results Ca2+ currents (CACNA1c+CACNB2b) were not affected by apamin (500 nM) (data are presented as median [25th percentile;75th percentile] (from –16 [–20;–10] to –17 [–19;–13] pA/pF, P = NS), but were reduced by nifedipine to –1.6 [–3.2;–1.3] pA/pF (p = 0.008). Na+ currents (SCN5A) were not affected by apamin (from –261 [–282;–145] to –268 [–379;–132] pA/pF, P = NS), but were reduced by flecainide to –57 [–70;–47] pA/pF (p = 0.018). None of the major K+ currents (IKs, IKr, IK1 and Ito) were inhibited by 500 nM of apamin (KCNQ1+KCNE1, from 28 [20]; [37] to 23 [18]; [32] pA/pF; KCNH2+KCNE2, from 28 [24]; [30] to 27 [24]; [29] pA/pF; KCNJ2, from –46 [–48;–40] to –46 [–51;–35] pA/pF; KCND3, from 608 [505;748] to 606 [454;684]). Apamin did not inhibit the INa or ICaL in isolated rabbit ventricular myocytes (INa, from –67 [–75;–59] to –68 [–71;–59] pA/pF; ICaL, from –16 [–17;–14] to –14 [–15;–13] pA/pF, P = NS for both). Conclusions Apamin does not inhibit human cardiac Na+ currents, L-type Ca2+ currents or other major K+ currents. These findings indicate that apamin is a specific SK current inhibitor in hearts as well as in other organs.
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Affiliation(s)
- Chih-Chieh Yu
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Integrated Diagnostic & Therapeutics, National Taiwan University, Taipei, Taiwan
| | - Tomohiko Ai
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Molecular Pathogenesis, Division of Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - James N. Weiss
- Cardiovascular Research Laboratory, Departments of Medicine (Cardiology) and Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Kobayashi K, Omuro N, Takahara A. The conventional antihistamine drug cyproheptadine lacks QT-interval-prolonging action in halothane-anesthetized guinea pigs: comparison with hydroxyzine. J Pharmacol Sci 2014; 124:92-8. [PMID: 24389819 DOI: 10.1254/jphs.13159fp] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Antihistamines are known to belong to the chemical class that may induce long QT syndrome. Among them, cyproheptadine has been shown to exert multifaceted actions on the ventricular repolarization phase; namely, shortening of the action potential duration at supra-therapeutic concentrations of 2 - 8 μM and prolongation of the QT interval at ≥ 10 μM. Since information is limited regarding the in vivo electrophysiological effects of cyproheptadine, we assessed it using the halothane-anesthetized guinea-pig model, which was compared with effects of another antihistamine drug, hydroxyzine. Sub-therapeutic to therapeutic doses of hydroxyzine at 1 and 10 mg/kg, i.v. prolonged the QT interval and duration of monophasic action potential, whereas therapeutic to supra-therapeutic doses of cyproheptadine at 0.1 and 1 mg/kg, i.v. hardly affected the indices of ventricular repolarization. These results suggest that cyproheptadine may be categorized into antihistamines with little effect on the ventricular repolarization.
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Affiliation(s)
- Kazuko Kobayashi
- Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Toho University, Japan
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He FZ, McLeod HL, Zhang W. Current pharmacogenomic studies on hERG potassium channels. Trends Mol Med 2013; 19:227-38. [PMID: 23369369 DOI: 10.1016/j.molmed.2012.12.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 12/18/2012] [Accepted: 12/27/2012] [Indexed: 11/25/2022]
Abstract
Genetic polymorphisms in human ether-a-go-go-related gene (hERG) potassium channels are associated with many complex diseases and sensitivity to channel-related drugs. Genotypes may underlie different sensitivities to the same drug, and different drugs selectively repair the functional deficits caused by individual mutations. In fact, not all drugs that block hERG function have adverse effects as previously thought. This suggests that the severe adverse reactions observed clinically may only occur in subjects with a particular genotype, but to others may be safe. Similarly, a drug that is ineffective in one population may be both safe and effective in another. Therefore, detecting polymorphisms in KCNH2 encoding hERG1 is of great significance in guiding the prevention and treatment of related diseases, re-evaluating drug safety, and individualizing treatment. This article reviews current pharmacogenomic studies on hERG potassium channels to provide a reference for developing individualized treatments and evaluating their safety.
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Affiliation(s)
- Fa-Zhong He
- Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha, Hunan 410078, PR China
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Lee BH, Lee SH, Chu D, Hyun JW, Choe H, Choi BH, Jo SH. Effects of the histamine H(1) receptor antagonist hydroxyzine on hERG K(+) channels and cardiac action potential duration. Acta Pharmacol Sin 2011; 32:1128-37. [PMID: 21892192 DOI: 10.1038/aps.2011.66] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
AIM To investigate the effects of hydroxyzine on human ether-a-go-go-related gene (hERG) channels to determine the electrolphysiological basis for its proarrhythmic effects. METHODS hERG channels were expressed in Xenopus oocytes and HEK293 cells, and the effects of hydroxyzine on the channels were examined using two-microelectrode voltage-clamp and patch-clamp techniques, respectively. The effects of hydroxyzine on action potential duration were examined in guinea pig ventricular myocytes using current clamp. RESULTS Hydroxyzine (0.2 and 2 μmol/L) significantly increased the action potential duration at 90% repolarization (APD(90)) in both concentration- and time-dependent manners. Hydroxyzine (0.03-3 μmol/L) blocked both the steady-state and tail hERG currents. The block was voltage-dependent, and the values of IC(50) for blocking the steady-state and tail currents at +20 mV was 0.18±0.02 μmol/L and 0.16±0.01 μmol/L, respectively, in HEK293 cells. Hydroxyzine (5 μmol/L) affected both the activated and the inactivated states of the channels, but not the closed state. The S6 domain mutation Y652A attenuated the blocking of hERG current by ~6-fold. CONCLUSION The results suggest that hydroxyzine could block hERG channels and prolong APD. The tyrosine at position 652 in the channel may be responsible for the proarrhythmic effects of hydroxyzine.
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Oka Y, Itoh H, Ding WG, Shimizu W, Makiyama T, Ohno S, Nishio Y, Sakaguchi T, Miyamoto A, Kawamura M, Matsuura H, Horie M. Atrioventricular block-induced Torsades de Pointes with clinical and molecular backgrounds similar to congenital long QT syndrome. Circ J 2010; 74:2562-71. [PMID: 20975234 DOI: 10.1253/circj.cj-10-0498] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Atrioventricular block (AVB) sometimes complicates QT prolongation and torsades de pointes (TdP). METHODS AND RESULTS The clinical and genetic background of 14 AVB patients (57±21 years, 13 females) who developed QT prolongation and TdP was analyzed. Electrophysiological characteristics of mutations were analyzed using heterologous expression in Chinese hamster ovary cells, together with computer simulation models. Every patient received a pacemaker or implantable cardioverter defibrillator; 3 patients had recurrence of TdP during follow-up because of pacing failure. Among the ECG parameters, QTc interval was prolonged to 561±76ms in the presence of AVB, but shortened to 495±42ms in the absence of AVB. Genetic screening for KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 revealed four heterozygous missense mutations of KCNQ1 or KCNH2 in 4 patients (28.6%). Functional analyses showed that all mutations had loss of functions and various gating dysfunctions of I(Ks) or I(Kr). Finally, action potential simulation based on the Luo-Rudy model demonstrated that most mutant channels induced bradycardia-related early afterdepolarizations. CONCLUSIONS Incidental AVB, as a trigger of TdP, can manifest as clinical phenotypes of long QT syndrome (LQTS), and that some patients with AVB-induced TdP share a genetic background with those with congenital LQTS.
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Affiliation(s)
- Yuko Oka
- Department of Respiratory and Cardiovascular Medicine, Shiga University of Medical Science, Otsu, Japan
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Smithburger PL, Seybert AL, Armahizer MJ, Kane-Gill SL. QT prolongation in the intensive care unit: commonly used medications and the impact of drug–drug interactions. Expert Opin Drug Saf 2010; 9:699-712. [DOI: 10.1517/14740331003739188] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Xing J, Ma J, Zhang P, Fan X. Block effect of capsaicin on hERG potassium currents is enhanced by S6 mutation at Y652. Eur J Pharmacol 2009; 630:1-9. [PMID: 19903464 DOI: 10.1016/j.ejphar.2009.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 10/16/2009] [Accepted: 11/03/2009] [Indexed: 11/19/2022]
Abstract
The objectives of this study were to investigate the inhibitory action of capsaicin on wild-type (WT) and mutation human ether-a-go-go-related gene (hERG) potassium channel currents (I(hERG)), and to determine whether mutations in the S6 region are significant for the inhibition of I(hERG) by capsaicin. The hERG channel (WT, Y652A and F656A) was expressed in Xenopus oocytes and studied using standard two-microelectrode voltage-clamp techniques. The results show that capsaicin blocks WT hERG in a concentration-dependent manner, with an IC(50) of 17.45microM and a negative shift in the steady-state inactivation curve. Characteristics of blockade were consistent with capsaicin causing components of block in both the closed and open channel states. However, mutating the Y652 residue to Ala enhances the blockade effect of capsaicin with an IC(50) of 4.11microM, whereas mutation of F656A does not significantly alter drug potency. Simultaneously, for Y652A, the steady-state activation parameter is shifted to a more positive value by 5mV and the inactivation parameter is shifted to a more negative value by -29mV in the presence of 25microM capsaicin. In conclusion, capsaicin blocks hERG channels by binding to both the closed and open channel states.Y652 was important as a molecular determinant of blockade. Mutation Y652A enhances the drug block, which may cause some patients to be particularly sensitive to capsaicin clinically.
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Affiliation(s)
- Junlian Xing
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and Technology, Wuhan, China
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Itoh H, Sakaguchi T, Ding WG, Watanabe E, Watanabe I, Nishio Y, Makiyama T, Ohno S, Akao M, Higashi Y, Zenda N, Kubota T, Mori C, Okajima K, Haruna T, Miyamoto A, Kawamura M, Ishida K, Nagaoka I, Oka Y, Nakazawa Y, Yao T, Jo H, Sugimoto Y, Ashihara T, Hayashi H, Ito M, Imoto K, Matsuura H, Horie M. Latent genetic backgrounds and molecular pathogenesis in drug-induced long-QT syndrome. Circ Arrhythm Electrophysiol 2009; 2:511-23. [PMID: 19843919 DOI: 10.1161/circep.109.862649] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Drugs with I(Kr)-blocking action cause secondary long-QT syndrome. Several cases have been associated with mutations of genes coding cardiac ion channels, but their frequency among patients affected by drug-induced long-QT syndrome (dLQTS) and the resultant molecular effects remain unknown. METHODS AND RESULTS Genetic testing was carried out for long-QT syndrome-related genes in 20 subjects with dLQTS and 176 subjects with congenital long-QT syndrome (cLQTS); electrophysiological characteristics of dLQTS-associated mutations were analyzed using a heterologous expression system with Chinese hamster ovary cells together with a computer simulation model. The positive mutation rate in dLQTS was similar to cLQTS (dLQTS versus cLQTS, 8 of 20 [40%] versus 91 of 176 [52%] subjects, P=0.32). The incidence of mutations was higher in patients with torsades de pointes induced by nonantiarrhythmic drugs than by antiarrhythmic drugs (antiarrhythmic versus others, 3 of 14 [21%] versus 5 of 6 [83%] subjects, P<0.05). When reconstituted in Chinese hamster ovary cells, KCNQ1 and KCNH2 mutant channels showed complex gating defects without dominant negative effects or a relatively mild decreased current density. Drug sensitivity for mutant channels was similar to that of the wild-type channel. With the Luo-Rudy simulation model of action potentials, action potential durations of most mutant channels were between those of wild-type and cLQTS. CONCLUSIONS dLQTS had a similar positive mutation rate compared with cLQTS, whereas the functional changes of these mutations identified in dLQTS were mild. When I(Kr)-blocking agents produce excessive QT prolongation (dLQTS), the underlying genetic background of the dLQTS subject should also be taken into consideration, as would be the case with cLQTS; dLQTS can be regarded as a latent form of long-QT syndrome.
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Affiliation(s)
- Hideki Itoh
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga 520-2192, Japan
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From the Literature. Mol Diagn Ther 2009. [DOI: 10.1007/bf03256332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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