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Whitledge JD, Watson CJ, Burns MM. Chronic Doxepin Toxicity Masquerading as Epilepsy in a 10-Year-Old Boy. J Med Toxicol 2023; 19:405-410. [PMID: 37682427 PMCID: PMC10522553 DOI: 10.1007/s13181-023-00966-y] [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: 06/08/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 09/09/2023] Open
Abstract
INTRODUCTION Chronic tricyclic antidepressant toxicity is rarely described in children. Symptoms include confusion, ataxia, and seizures. Toxicity may result from dosing error, CYP2C19 and CYP2D6 genetic variability, and drug-drug interactions. Chronic doxepin toxicity has not been previously reported in children. Doxepin is prescribed for insomnia and depression, with a maximum off-label dose of 3 mg/kg in children. We present a case of chronic doxepin toxicity mimicking epilepsy in a child attributable to three potential factors: supratherapeutic dosing, pharmacogenomic variability, and drug-drug interactions. CASE REPORT A 10-year-old boy with insomnia, diagnosed with epilepsy 6 months prior, presented to an emergency department with confusion, ataxia, and increasing seizure frequency. He was prescribed doxepin for insomnia and four antiepileptics for seizures. After admission, he had two seizures and remained confused. EKGs showed QRS prolongation, suggesting doxepin toxicity. Doxepin-nordoxepin combined serum concentration was 1419 ng/mL (therapeutic 100-300 ng/mL), confirming doxepin toxicity. Outpatient records showed onset of confusion and seizures as doxepin dose was gradually uptitrated to 300 mg nightly (4.41 mg/kg). Symptoms worsened following addition of clobazam (CYP2D6 inhibitor) and topiramate (CYP2C19 inhibitor). Following doxepin discontinuation, all symptoms resolved. CYP2D6 testing showed intermediate metabolizer phenotype (CYP2D6*1/*4; activity score = 1.0; copy number = 2.0). No seizures have occurred in more than one year since doxepin discontinuation. DISCUSSION Caution must be exercised when prescribing doxepin. Pharmacogenomics, dose, drug-drug interactions, and age should be considered. Chronic toxicity should be contemplated in patients taking doxepin without acute overdose who present with persistent neurologic abnormalities including seizure.
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Affiliation(s)
- James D Whitledge
- Harvard Medical Toxicology Fellowship, Boston, MA, USA.
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
| | - C James Watson
- Harvard Medical Toxicology Fellowship, Boston, MA, USA
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Department of Emergency Medicine, Maine Medical Center, Portland, ME, USA
| | - Michele M Burns
- Harvard Medical Toxicology Fellowship, Boston, MA, USA
- Division of Emergency Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
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2
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Myers B, Reddy V, Chan S, Thibodeaux Q, Brownstone N, Koo J. Optimizing doxepin therapy in dermatology: introducing blood level monitoring and genotype testing. J DERMATOL TREAT 2022; 33:87-93. [PMID: 32347140 DOI: 10.1080/09546634.2020.1762841] [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: 10/24/2022]
Abstract
Doxepin, a tricyclic antidepressant, is the most efficacious antipruritic available to dermatologists; however its use is often suboptimal because of significant interindividual variability in doxepin plasma levels and clinical response between patients taking the same dose. As result, the Food and Drug Administration approves a maximum dose of 300 mg of doxepin per day and a 10 mg per cc liquid doxepin concentrate. These allow patients to significantly increase or decrease their dose, due to either a lack of clinical efficacy or side effects at typical dermatologic doses (often 10-25 mg per day). This review initially discusses the unique advantages of doxepin in dermatology. Then, it explores internal and external reasons why doxepin plasma levels and clinical response vary so significantly between patients, including genetic polymorphisms, drug interactions, comorbidities, sex, and ethnicity. Blood level monitoring is introduced, a tool dermatologists can use to optimize doxepin dosing in patients responding subtherapeutically to typical dermatologic doses. Without blood level monitoring, patients initially unresponsive to treatment could be labeled treatment failures when in fact they may be cases of inadequate dosing. Blood level monitoring allows for safe dose adjustments in these individuals to maximize patients' chances of achieving therapeutic success with this agent.
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Affiliation(s)
- Bridget Myers
- Dermatology, University of California, San Francisco, CA, USA
| | - Vidhatha Reddy
- Dermatology, University of California, San Francisco, CA, USA
| | - Stephanie Chan
- Dermatology, University of California, San Francisco, CA, USA
| | | | | | - John Koo
- Dermatology, University of California, San Francisco, CA, USA
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3
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Tien N, Wu TY, Lai JN, Lin CL, Hsiao YC, Khaw JY, Lim YP. Influences of antidepressant medications on the risk of developing hyperlipidemia in patients with depression by a population-based cohort study and on in vitro hepatic lipogenic-related gene expression. J Affect Disord 2021; 295:271-283. [PMID: 34482059 DOI: 10.1016/j.jad.2021.08.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Depression increases the risk of cardiovascular disease (CVD). The association between antidepressant medications (ADMs) and CVD remains controversial. Hyperlipidemia is a risk factor for CVD. We conducted a nationwide population-based retrospective cohort study to examine depression and ADM use on the risk of developing hyperlipidemia. The effects of ADMs on the expression of lipogenesis-related hepatic genes were also evaluated. METHODS We obtained data from the Longitudinal Health Insurance Database of Taiwan on patients with new-onset depression and a comparison cohort without depression. A Cox proportional hazards regression model was used to analyze the differences in the risk of developing hyperlipidemia between these two cohorts. We also examined the influence of ADMs on the expression of lipogenesis-related hepatic genes. RESULTS After adjustment for comorbidities and confounding factors, the case group (N = 38,322) had a higher risk for hyperlipidemia than that of the control cohort (N = 38,322) [adjusted hazards ratio (aHR) =1.16]. Patients with depression who did not receive ADM therapy exhibited a significantly higher risk of hyperlipidemia (aHR = 1.61). However, in patients with depression treated with ADMs, the risk of developing hyperlipidemia was significantly lowered compared to the patients without ADMs (all aHR < 0.81). Gene expression analysis indicated that ADMs downregulated the expression of lipogenesis-related hepatic genes. LIMITATIONS Unmeasured confounding risk factors for hyperlipidemia might not have been included in the study. CONCLUSIONS ADMs reduced hyperlipidemia risk in patients with depression, partly by downregulating the expression of lipogenesis-related genes and improving the patients' lipid profiles. Early diagnosis and management of hyperlipidemia would further facilitate the prevention of CVD.
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Affiliation(s)
- Ni Tien
- Department of Laboratory Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Tien-Yuan Wu
- Department of Pharmacy, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan; Department of Pharmacology, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Jung-Nien Lai
- Department of Chinese Medicine, China Medical University Hospital, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Cheng-Li Lin
- Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Chi Hsiao
- Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Jie-Yee Khaw
- Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Yun-Ping Lim
- Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan; Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
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4
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Eap CB, Gründer G, Baumann P, Ansermot N, Conca A, Corruble E, Crettol S, Dahl ML, de Leon J, Greiner C, Howes O, Kim E, Lanzenberger R, Meyer JH, Moessner R, Mulder H, Müller DJ, Reis M, Riederer P, Ruhe HG, Spigset O, Spina E, Stegman B, Steimer W, Stingl J, Suzen S, Uchida H, Unterecker S, Vandenberghe F, Hiemke C. Tools for optimising pharmacotherapy in psychiatry (therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests): focus on antidepressants. World J Biol Psychiatry 2021; 22:561-628. [PMID: 33977870 DOI: 10.1080/15622975.2021.1878427] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Objectives: More than 40 drugs are available to treat affective disorders. Individual selection of the optimal drug and dose is required to attain the highest possible efficacy and acceptable tolerability for every patient.Methods: This review, which includes more than 500 articles selected by 30 experts, combines relevant knowledge on studies investigating the pharmacokinetics, pharmacodynamics and pharmacogenetics of 33 antidepressant drugs and of 4 drugs approved for augmentation in cases of insufficient response to antidepressant monotherapy. Such studies typically measure drug concentrations in blood (i.e. therapeutic drug monitoring) and genotype relevant genetic polymorphisms of enzymes, transporters or receptors involved in drug metabolism or mechanism of action. Imaging studies, primarily positron emission tomography that relates drug concentrations in blood and radioligand binding, are considered to quantify target structure occupancy by the antidepressant drugs in vivo. Results: Evidence is given that in vivo imaging, therapeutic drug monitoring and genotyping and/or phenotyping of drug metabolising enzymes should be an integral part in the development of any new antidepressant drug.Conclusions: To guide antidepressant drug therapy in everyday practice, there are multiple indications such as uncertain adherence, polypharmacy, nonresponse and/or adverse reactions under therapeutically recommended doses, where therapeutic drug monitoring and cytochrome P450 genotyping and/or phenotyping should be applied as valid tools of precision medicine.
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Affiliation(s)
- C B Eap
- Unit of Pharmacogenetics and Clinical Psychopharmacology, Center for Psychiatric Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,Center for Research and Innovation in Clinical Pharmaceutical Sciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland.,Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland.,Institute of Pharmaceutical Sciences of Western Switzerland, University of Lausanne, Switzerland, Geneva, Switzerland
| | - G Gründer
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - P Baumann
- Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - N Ansermot
- Unit of Pharmacogenetics and Clinical Psychopharmacology, Center for Psychiatric Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - A Conca
- Department of Psychiatry, Health Service District Bolzano, Bolzano, Italy.,Department of Child and Adolescent Psychiatry, South Tyrolean Regional Health Service, Bolzano, Italy
| | - E Corruble
- INSERM CESP, Team ≪MOODS≫, Service Hospitalo-Universitaire de Psychiatrie, Universite Paris Saclay, Le Kremlin Bicetre, France.,Service Hospitalo-Universitaire de Psychiatrie, Hôpital Bicêtre, Assistance Publique Hôpitaux de Paris, Le Kremlin Bicêtre, France
| | - S Crettol
- Unit of Pharmacogenetics and Clinical Psychopharmacology, Center for Psychiatric Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - M L Dahl
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - J de Leon
- Eastern State Hospital, University of Kentucky Mental Health Research Center, Lexington, KY, USA
| | - C Greiner
- Bundesinstitut für Arzneimittel und Medizinprodukte, Bonn, Germany
| | - O Howes
- King's College London and MRC London Institute of Medical Sciences (LMS)-Imperial College, London, UK
| | - E Kim
- Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, South Korea.,Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea
| | - R Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - J H Meyer
- Campbell Family Mental Health Research Institute, CAMH and Department of Psychiatry, University of Toronto, Toronto, Canada
| | - R Moessner
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - H Mulder
- Department of Clinical Pharmacy, Wilhelmina Hospital Assen, Assen, The Netherlands.,GGZ Drenthe Mental Health Services Drenthe, Assen, The Netherlands.,Department of Pharmacotherapy, Epidemiology and Economics, Department of Pharmacy and Pharmaceutical Sciences, University of Groningen, Groningen, The Netherlands.,Department of Psychiatry, Interdisciplinary Centre for Psychopathology and Emotion Regulation, University of Groningen, Groningen, The Netherlands
| | - D J Müller
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - M Reis
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.,Clinical Chemistry and Pharmacology, Skåne University Hospital, Lund, Sweden
| | - P Riederer
- Center of Mental Health, Clinic and Policlinic for Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Würzburg, Germany.,Department of Psychiatry, University of Southern Denmark Odense, Odense, Denmark
| | - H G Ruhe
- Department of Psychiatry, Radboudumc, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, Netherlands
| | - O Spigset
- Department of Clinical Pharmacology, St. Olav University Hospital, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - E Spina
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - B Stegman
- Institut für Pharmazie der Universität Regensburg, Regensburg, Germany
| | - W Steimer
- Institute for Clinical Chemistry and Pathobiochemistry, Technical University of Munich, Munich, Germany
| | - J Stingl
- Institute for Clinical Pharmacology, University Hospital of RWTH Aachen, Germany
| | - S Suzen
- Department of Toxicology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - H Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - S Unterecker
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital of Würzburg, Würzburg, Germany
| | - F Vandenberghe
- Unit of Pharmacogenetics and Clinical Psychopharmacology, Center for Psychiatric Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - C Hiemke
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
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5
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Shahhoseini F, Langille EA, Azizi A, Bottaro CS. Thin film molecularly imprinted polymer (TF-MIP), a selective and single-use extraction device for high-throughput analysis of biological samples. Analyst 2021; 146:3157-3168. [PMID: 33999057 DOI: 10.1039/d0an02228d] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Enhancing selectivity, reducing matrix effects and increasing analytical throughput have been the main objectives in the development of biological sample preparation techniques. A thin film molecularly imprinted polymer (MIP) is employed for extraction and analysis of tricyclic antidepressants (TCAs) as a model class of compounds in human plasma for the first time to reach the abovementioned goals. The thin film MIPs prepared on a metal substrate can be used directly for extraction from biological matrices with no sample manipulation steps and no pre-conditioning. This method was validated with good linearity (R2 > 0.99 in 1.0-500.0 ng mL-1 range), excellent accuracy (90% -110%) and precision (RSD % value less than 15%) in pooled human plasma samples (N = 3). The limits of quantitation (LOQ) for TCAs in plasma samples were between 1.0-5.0 ng mL-1 which are lower than the therapeutic ranges of these drugs. Kinetic and isotherm studies showed the superior performance of MIP sorbent compared to a non-imprinted polymer (NIP) sorbent in extracting TCAs from a bovine serum albumin (BSA) solution. The optimized and validated method for pooled human plasma was utilized for monitoring the concentration of TCAs in three patient samples who had been prescribed TCAs. These selective single-use thin film extraction devices are promising for efficient and fast procedures for analyzing biological samples.
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Affiliation(s)
- Fereshteh Shahhoseini
- Department of Chemistry, Memorial University of Newfoundland, St. John's, A1B 3X7, Canada.
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6
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Chan S, Reddy V, Myers B, Brownstone N, Thibodeaux Q, Koo J. High-dose doxepin for the treatment of chronic, intractable scalp pruritus. JAAD Case Rep 2020; 8:71-73. [PMID: 33521215 PMCID: PMC7820306 DOI: 10.1016/j.jdcr.2020.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Stephanie Chan
- Department of Dermatology, University of California, San Francisco, California
| | - Vidhatha Reddy
- Department of Dermatology, University of California, San Francisco, California
| | - Bridget Myers
- Department of Dermatology, University of California, San Francisco, California
| | - Nicholas Brownstone
- Department of Dermatology, University of California, San Francisco, California
| | - Quinn Thibodeaux
- Department of Dermatology, University of California, San Francisco, California
| | - John Koo
- Department of Dermatology, University of California, San Francisco, California
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7
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Dose escalation of doxepin for intractable pruritus. J Am Acad Dermatol 2018; 79:e37. [DOI: 10.1016/j.jaad.2018.05.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 11/24/2022]
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8
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Connor CJ. Management of the psychological comorbidities of dermatological conditions: practitioners' guidelines. Clin Cosmet Investig Dermatol 2017; 10:117-132. [PMID: 28458571 PMCID: PMC5404497 DOI: 10.2147/ccid.s111041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dermatological disease can be devastating for patients, and although dermatologists are focused on remedying the cutaneous manifestations of these conditions, it is easy to miss the psychological suffering lurking below. Studies reveal that psychiatric comorbidity in dermatology is highly prevalent. Undetected psychopathology can greatly decrease a patient's quality of life and even contribute significantly to the clinical severity of their skin disease. For these reasons, it is vital that practitioners learn to detect psychological distress when it is present, and it is equally essential that they understand the treatment options available for effective intervention. Without training in psychiatric diagnosis and psychopharmacology, dermatologists can easily feel overwhelmed or out of their comfort zone when faced with the need to manage such conditions, but with the negative stigma associated with psychiatric disease in general, a psychiatric referral is often refused by patients, and the dermatologist is thus left with the responsibility. Uncertainty abounds in such situations, but this review seeks to alleviate the discomfort with psychodermatological disease and share practical and impactful recommendations to assist in diagnosis and treatment. In a busy dermatology clinic, the key is effective and efficient screening, combined with a repertoire of pharmacological and non-pharmacological treatment options that can be dispersed through an algorithmic approach according to the specific findings of that screening. By implementing these recommendations into practice, dermatologists may begin to gain comfort with the management of psychocutaneous disease and, as a specialty, may expand to fill a hole in patient care that is truly significant for patients, their families, and our communities as a whole.
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Affiliation(s)
- Cody J Connor
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA
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9
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Geue S, Walker-Allgaier B, Eißler D, Tegtmeyer R, Schaub M, Lang F, Gawaz M, Borst O, Münzer P. Doxepin inhibits GPVI-dependent platelet Ca 2+ signaling and collagen-dependent thrombus formation. Am J Physiol Cell Physiol 2017; 312:C765-C774. [PMID: 28404545 DOI: 10.1152/ajpcell.00262.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 12/24/2022]
Abstract
Platelet adhesion, activation, and aggregation are essential for primary hemostasis, but are also critically involved in the development of acute arterial thrombotic occlusion. Stimulation of the collagen receptor glycoprotein VI (GPVI) leads to phospholipase Cγ2-dependent inositol triphosphate (IP3) production with subsequent platelet activation, due to increased intracellular Ca2+ concentration ([Ca2+]i). Although tricyclic antidepressants have been shown to potentially impair platelet activation, nothing is hitherto known about potential effects of the tricyclic antidepressant doxepin on platelet Ca2+ signaling and thrombus formation. As shown in the present study, doxepin significantly diminished the stimulatory effect of GPVI agonist collagen-related peptide (CRP) on intracellular Ca2+ release as well as subsequent extracellular Ca2+ influx. Doxepin was partially effective by impairment of CRP-dependent IP3 production. Moreover, doxepin abrogated CRP-induced platelet degranulation and integrin αIIbβ3 activation and aggregation. Finally, doxepin markedly blunted in vitro platelet adhesion to collagen and thrombus formation under high arterial shear rates (1,700-s). In conclusion, doxepin is a powerful inhibitor of GPVI-dependent platelet Ca2+ signaling, platelet activation, and thrombus formation.
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Affiliation(s)
- Sascha Geue
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Britta Walker-Allgaier
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Daniela Eißler
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Roland Tegtmeyer
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Malte Schaub
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Florian Lang
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and.,Department of Physiology, University of Tuebingen, Tuebingen, Germany
| | - Meinrad Gawaz
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Oliver Borst
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
| | - Patrick Münzer
- Department of Cardiology and Cardiovascular Medicine, University of Tuebingen, Tuebingen, Germany; and
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10
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Fahimirad B, Asghari A, Bazregar M, Rajabi M, Fahimi E. Application of tandem dispersive liquid-liquid microextraction for the determination of doxepin, citalopram, and fluvoxamine in complicated samples. J Sep Sci 2016; 39:4828-4834. [DOI: 10.1002/jssc.201600673] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 10/21/2016] [Accepted: 10/23/2016] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | - Maryam Rajabi
- Department of Chemistry; Semnan University; Semnan Iran
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11
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Park HJ, Baik HJ, Kim DY, Lee GY, Woo JH, Zuo Z, Chung RK. Doxepin and imipramine but not fluoxetine reduce the activity of the rat glutamate transporter EAAT3 expressed in Xenopus oocytes. BMC Anesthesiol 2015; 15:116. [PMID: 26253075 PMCID: PMC4528682 DOI: 10.1186/s12871-015-0098-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/28/2015] [Indexed: 11/10/2022] Open
Abstract
Background Many researchers have suggested that the glutamatergic system may be involved in the effects of antidepressant therapies. We investigated the effects of doxepin, imipramine, and fluoxetine on the excitatory amino acid transporter type 3 (EAAT3). Methods EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 mRNA. Membrane currents were recorded after application of L-glutamate (30 μM) in the presence or absence of various concentrations of doxepin, imipramine, and fluoxetine. To study the effects of protein kinase C (PKC) activation on EAAT3 activity, oocytes were pre-incubated with phorbol 12-myristate-13-acetate (PMA) before application of imipramine and doxepin. Results Doxepin at 0.063–1.58 μM significantly decreased EAAT3 activity. Imipramine reduced EAAT3 activity in a concentration-dependent manner at 0.16–0.95 μM. However, fluoxetine did not affect EAAT3 activity, and PMA increased EAAT3 activity. At 0.32 μM, imipramine caused an equivalent decrease in EAAT3 activity in the presence or absence of PMA. However, 0.79 μM doxepin did not abolish the enhancement of EAAT3 activity by PMA. Conclusions We showed that doxepin and imipramine, but not fluoxetine, inhibited EAAT3 activity at clinically relevant concentrations. This reveals a novel mechanism of action for doxepin and imipramine; that they increase glutamatergic neurotransmission. PKC may be involved in the effects of doxepin on EAAT3, but is not involved in the effects of imipramine at the concentrations studied.
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Affiliation(s)
- Hye Jin Park
- Dasom anesthesia and analgesia practice association, Seoul, Republic of Korea.
| | - Hee Jung Baik
- Department of anesthesiology and pain medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
| | - Dong Yeon Kim
- Department of anesthesiology and pain medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
| | - Guie Yong Lee
- Department of anesthesiology and pain medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
| | - Jae Hee Woo
- Department of anesthesiology and pain medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA.
| | - Rack Kyung Chung
- Department of anesthesiology and pain medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
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Mansbach RS, Ludington E, Rogowski R, Kittrelle JP, Jochelson P. A Placebo- and Active-Controlled Assessment of 6- and 50-mg Oral Doxepin on Cardiac Repolarization in Healthy Volunteers: A Thorough QT Evaluation. Clin Ther 2011; 33:851-62. [DOI: 10.1016/j.clinthera.2011.05.092] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2011] [Indexed: 10/18/2022]
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13
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Doxepin and nordoxepin concentrations in body fluids and tissues in doxepin associated deaths. Forensic Sci Int 2009; 190:74-9. [DOI: 10.1016/j.forsciint.2009.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 05/17/2009] [Accepted: 05/20/2009] [Indexed: 11/18/2022]
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Duncan R, McPate M, Ridley J, Gao Z, James A, Leishman D, Leaney J, Witchel H, Hancox J. Inhibition of the HERG potassium channel by the tricyclic antidepressant doxepin. Biochem Pharmacol 2007; 74:425-37. [PMID: 17560554 PMCID: PMC1920586 DOI: 10.1016/j.bcp.2007.04.024] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2007] [Revised: 04/25/2007] [Accepted: 04/27/2007] [Indexed: 11/25/2022]
Abstract
HERG (human ether-à-go-go-related gene) encodes channels responsible for the cardiac rapid delayed rectifier potassium current, IKr. This study investigated the effects on HERG channels of doxepin, a tricyclic antidepressant linked to QT interval prolongation and cardiac arrhythmia. Whole-cell patch-clamp recordings were made at 37 °C of recombinant HERG channel current (IHERG), and of native IKr ‘tails’ from rabbit ventricular myocytes. Doxepin inhibited IHERG with an IC50 value of 6.5 ± 1.4 μM and native IKr with an IC50 of 4.4 ± 0.6 μM. The inhibitory effect on IHERG developed rapidly upon membrane depolarization, but with no significant dependence on voltage and with little alteration to the voltage-dependent kinetics of IHERG. Neither the S631A nor N588K inactivation-attenuating mutations (of residues located in the channel pore and external S5-Pore linker, respectively) significantly reduced the potency of inhibition. The S6 point mutation Y652A increased the IC50 for IHERG blockade by ∼4.2-fold; the F656A mutant also attenuated doxepin's action at some concentrations. HERG channel blockade is likely to underpin reported cases of QT interval prolongation with doxepin. Notably, this study also establishes doxepin as an effective inhibitor of mutant (N588K) HERG channels responsible for variant 1 of the short QT syndrome.
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Affiliation(s)
- R.S. Duncan
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | - M.J. McPate
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | - J.M. Ridley
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | - Z. Gao
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | - A.F. James
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | - D.J. Leishman
- Pfizer Global Research & Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, UK
- Lilly Research Laboratories, Greenfield Laboratories, PO Box 708, Greenfield IN, 46140, USA
| | - J.L. Leaney
- Pfizer Global Research & Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, UK
| | - H.J. Witchel
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
- Corresponding authors. Tel.: +117 928 9028; fax: +117 928 8923.
| | - J.C. Hancox
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
- Corresponding authors. Tel.: +117 928 9028; fax: +117 928 8923.
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15
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Adli M, Baethge C, Heinz A, Langlitz N, Bauer M. Is dose escalation of antidepressants a rational strategy after a medium-dose treatment has failed? A systematic review. Eur Arch Psychiatry Clin Neurosci 2005; 255:387-400. [PMID: 15868067 DOI: 10.1007/s00406-005-0579-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Accepted: 02/08/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Maximizing the dose of antidepressants is widely recommended in cases of non-response to medium-dose treatment. However, scientific evidence supporting high-dose treatment is scarce. Systematic studies comparing dose escalation with alternative strategies for refractory depression (i. e. augmentation or change of compound) are lacking. The aim of this publication is to review available direct and indirect evidence concerning dose increase of antidepressants after a medium-dose trial has failed. METHOD We performed a systematic literature search of Medline (1966-2003) and reviewed studies and publication references for available evidence. DATA SOURCES AND STUDY SELECTION Studies of the following types were included: 1) dose increase studies in treatment refractory patients, 2) comparative dose studies, 3) therapeutic drug monitoring studies. RESULTS Available data suggest differential efficacy of various pharmacological classes at more than medium-dosage. Direct evidence shows no increase of efficacy with high-dose selective serotonin reuptake inhibitor (SSRI) treatment; however, indirect evidence suggests enhanced therapeutic efficacy with high-dose tricyclic antidepressants. Few clinical data show ultra-high-dose treatment with the irreversible monoamine-oxidase-(MAO-) inhibitor tranylcypromine to be effective for refractory depression. Data concerning other selective compounds are insufficient to allow any definitive conclusion on the benefit of high-dose treatment. CONCLUSIONS Based on available data highdose antidepressant treatment of patients refractory to medium-dose treatment is recommended for tricyclic compounds but not for SSRI. Some data suggest beneficial efficacy of ultra-high doses of the irreversible MAOI tranylcypromine. Research on other substance groups is limited and inconclusive. Prospective studies comparing dose escalation with alternative strategies for treatment of non-responding patients are needed.
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Affiliation(s)
- Mazda Adli
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Charité Mitte, Germany.
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16
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Baumann P, Ulrich S, Eckermann G, Gerlach M, Kuss HJ, Laux G, Müller-Oerlinghausen B, Rao ML, Riederer P, Zernig G, Hiemke C. The AGNP-TDM Expert Group Consensus Guidelines: focus on therapeutic monitoring of antidepressants. DIALOGUES IN CLINICAL NEUROSCIENCE 2005. [PMID: 16156382 PMCID: PMC3181735 DOI: 10.31887/dcns.2005.7.3/pbaumann] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Therapeutic drug monitoring (TDM) of psychotropic drugs such as antidepressants has been widely introduced for optimization of pharmacotherapy in psychiatric patients. The interdisciplinary TDM group of the Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP) has worked out consensus guidelines with the aim of providing psychiatrists and TDM laboratories with a tool to optimize the use of TDM. Five research-based levels of recommendation were defined with regard to routine monitoring of drug plasma concentrations: (i) strongly recommended; (ii) recommended; (iii) useful; (iv) probably useful; and (v) not recommended. In addition, a list of indications that justify the use of TDM is presented, eg, control of compliance, lack of clinical response or adverse effects at recommended doses, drug interactions, pharmacovigilance programs, presence of a genetic particularity concerning drug metabolism, and children, adolescents, and elderly patients. For some drugs, studies on therapeutic ranges are lacking, but target ranges for clinically relevant plasma concentrations are presented for most drugs, based on pharmacokinetic studies reported in the literature. For many antidepressants, a thorough analysis of the literature on studies dealing with the plasma concentration-clinical effectiveness relationship allowed inclusion of therapeutic ranges of plasma concentrations. In addition, recommendations are made with regard to the combination of pharmacogenetic (phenotyping or genotyping) tests with TDM. Finally, practical instructions are given for the laboratory practitioners and the treating physicians how to use TDM: preparation of TDM, drug analysis, reporting and interpretation of results, and adequate use of information for patient treatment TDM is a complex process that needs optimal interdisciplinary coordination of a procedure implicating patients, treating physicians, clinical pharmacologists, and clinical laboratory specialists. These consensus guidelines should be helpful for optimizing TDM of antidepressants.
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Affiliation(s)
- Pierre Baumann
- Department of Psychiatry, University of Lausanne, Prilly Lausanne, Switzerland.
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17
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Kirchheiner J, Henckel HB, Franke L, Meineke I, Tzvetkov M, Uebelhack R, Roots I, Brockmöller J. Impact of the CYP2D6 ultra-rapid metabolizer genotype on doxepin pharmacokinetics and serotonin in platelets. Pharmacogenet Genomics 2005; 15:579-87. [PMID: 16007002 DOI: 10.1097/01.fpc.0000167331.30905.9e] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION CYP2D6 gene duplication causing ultrafast metabolism is one reason for failure in responding to CYP2D6-metabolized antidepressants. We studied the effect of the CYP2D6 duplication genotype on doxepin pharmacokinetics and platelet serotonin uptake and concentrations. METHODS Pharmacokinetics of trans (E)- and cis (Z)-doxepin and N-desmethyldoxepin were analyzed after a single dose of 75 mg doxepin in 11 ultrafast metabolizers (UM), 11 extensive metabolizers (EM) and 3 poor metabolizers (PM), identified by genotyping for CYP2D6 alleles *2, *3, *4, *5, *6, *9, *10, *35, *41 and specific analyses to characterize gene duplication. Platelet serotonin concentrations were measured by HPLC. RESULTS A trend for lower AUC of the active principle (sum of doxepin and N-desmethyldoxepin) in UMs versus EMs was detected (575 versus 1,000 nmol h/l, P=0.07), mainly due to the differences in desmethyldoxepin concentrations (P=0.003). Stereoselective analysis showed a significant effect of the UM genotype on (E)-doxepin pharmacokinetic parameters whereas those of (Z)-doxepin did not differ between the CYP2D6 genotype groups. The 75-mg doxepin dose had no effect on platelet serotonin concentration and uptake, but serotonin concentrations in platelets were significantly higher in UM in comparison to the EM and PM groups. At baseline, these concentrations were 462, 399, and 292 ng/10 platelets in UM, EM and PM (P<0.0001 for trend). CONCLUSIONS At the same dose, internal exposure to doxepin differed by more than ten-fold between the CYP2D6 genotype groups. CYP2D6 may have an effect on platelet serotonin explained by salvage pathways of 5-methoxytryptamine to serotonin mediated by CYP2D6; however, this finding requires further confirmatory experiments.
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Affiliation(s)
- Julia Kirchheiner
- Institute of Clinical Pharmacology, Laboratory of Clinical Neurobiology, Charité University Medicine, Berlin, Germany.
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Kirchheiner J, Meineke I, Müller G, Roots I, Brockmöller J. Contributions of CYP2D6, CYP2C9 and CYP2C19 to the biotransformation of E- and Z-doxepin in healthy volunteers. PHARMACOGENETICS 2002; 12:571-80. [PMID: 12360109 DOI: 10.1097/00008571-200210000-00010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In-vitro data indicated a contribution of cytochrome P450 enzymes 1A2, 3A4, 2C9, 2C19 and 2D6 to biotransformation of doxepin. We studied the effects of genetic polymorphisms in CYP2D6, CYP2C9 and CYP2C19 on E- and Z-doxepin pharmacokinetics in humans. Doxepin kinetics was studied after a single oral dose of 75 mg in healthy volunteers genotyped as extensive (EM), intermediate (IM) and poor (PM) metabolizers of substrates of CYP2D6 and of CYP2C19 and as slow metabolizers with the CYP2C9 genotype *3/*3. E-, Z-doxepin and -desmethyldoxepin were quantified in plasma by HPLC. Data were analyzed by non-parametric pharmacokinetics and statistics and by population pharmacokinetic modeling considering effects of genotype on clearance and bioavailability. Mean E-doxepin clearance (95% confidence interval) was 406 (390-445), 247 (241-271), and 127 (124-139) l h(-1) in EMs, IMs and PMs of CYP2D6. In addition, EMs had about 2-fold lower bioavailability compared with PMs indicating significant contribution of CYP2D6 to E-doxepin first-pass metabolism. E-doxepin oral clearance was also significantly lower in carriers of CYP2C9*3/*3 (238 l h(-1) ). CYP2C19 was involved in Z-doxepin metabolism with 2.5-fold differences in oral clearances (73 l h(-1) in CYP2C19 PMs compared with 191 l h(-1) in EMs). The area under the curve (0-48 h) of the active metabolite -desmethyldoxepin was dependent on CYP2D6 genotype with a median of 5.28, 1.35, and 1.28 nmol l h(-1) in PMs, IMs, and EMs of CYP2D6. The genetically polymorphic enzymes exhibited highly stereoselective effects on doxepin biotransformation in humans. The CYP2D6 polymorphism had a major impact on E-doxepin pharmacokinetics and CYP2D6 PMs might be at an elevated risk for adverse drug effects when treated with common recommended doses.
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Affiliation(s)
- Julia Kirchheiner
- Institute of Clinical Pharmacology, University Medical Center Charité, Humboldt University Berlin, Berlin, Germany.
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