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Wu Y, Song W, Zhu D, Wang Y, Che G. Risk factors for cough after pulmonary resection. World J Surg Oncol 2023; 21:348. [PMID: 37924125 PMCID: PMC10623749 DOI: 10.1186/s12957-023-03235-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: 08/22/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023] Open
Abstract
BACKGROUND To investigate the risk factors for cough after pulmonary resection. METHODS The PubMed, Embase, Web of Science, ClinicalTrials.gov, and China National Knowledge Network databases were searched from inception to November 2022. The Q tests and I2 statistic were used to evaluate the heterogeneity. Odds ratios (OR) were combined using the inverse variance method. All statistical analyses were performed by RevMan 5.4.1. RESULTS Nineteen studies with 4755 patients were included, the incidence of postoperative cough was 21.1%-55.8%. The results showed that young age [OR = 0.66, 95% CI (0.46, 0.96), p = 0.03], female sex [OR = 1.69, 95% CI (1.07, 2.66), p = 0.02], preoperative cough [OR = 5.96, 95% CI (2.58, 13.73), p < 0.01], right lobe operation [OR = 2.14, 95% CI (1.44, 3.19), p < 0.01], lobectomy [OR = 3.70, 95% CI (1.73, 7.90), p < 0.01], subcarinal lymph node dissection [OR = 3.45, 95% CI (1.86, 6.39), p < 0.01], mediastinal lymph node removal [OR = 3.49, 95% CI (2.07, 5.89), p < 0.01], closure of bronchial stump with stapler [OR = 5.19, 95% CI (1.79, 15.07), p < 0.01], peritracheal lymph node resection [OR = 3.05, 95%CI (1.40,6.64), p < 0.01], postoperative acid reflux [OR = 11.07, 95%CI (4.38,28.02), p < 0.01] were independent risk factors for cough after pulmonary resection. CONCLUSIONS Young age, female sex, preoperative cough, right lobe operation, lobectomy, subcarinal lymph node dissection, mediastinal lymph node removal, closure of bronchial stump with stapler, peritracheal lymph node resection, and postoperative acid reflux are independent risk factors for cough after pulmonary resection.
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Affiliation(s)
- Yongming Wu
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Lung Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wenpeng Song
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Lung Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Dongmei Zhu
- Bengbu Medical College, Bengbu, Anhui, China
- The People's Hospital of Bozhou, Bozhou, Anhui, China
| | - Yan Wang
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Guowei Che
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
- Lung Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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Abstract
Cough sensitivity can be described as the reaction intensity of the cough reflex to different stimuli which activate chemically and mechanically sensitive vagal afferent nerves innervating airways and lungs. Measurement of cough reflex sensitivity plays an important role in revealing the underlying mechanisms of cough and evaluating the effects of pharmacological interventions. Besides, different responses to cough suppression therapies indicate the existence of cough hypersensitivity. In consideration of these factors stated above, cough sensitivity should therefore be assessed with a variety of cough challenge tests. Based on the neuroanatomical characteristics of the cough reflex, chemical challenge tests have been developed to objectively assess cough sensitivity. In cough inhalation challenges, capsaicin and citric acid are commonly used as the tussive agents to induce cough, which are validated for describing a profile of cough sensitivity to chemical irritants. Recently, mechanical methodologies have also been tried to measure the mechanical sensitivity of the cough reflex. Methodological consideration and selection are necessary for the reasonable assessment of cough sensitivity while employing cough challenges in clinical trials. Thus, in this review, we will focus on describing various methodologies of cough sensitivity measurement and, detailing some factors influencing on the accuracy of outcomes in the experimentally induced cough.
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Affiliation(s)
- Yonglin Mai
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Nanshan School of Medicine, Guangzhou Medical University, Guangzhou, China
| | - Liman Fang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Shuxin Zhong
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - S Dushinka Shaniya Helen de Silva
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,International College of Education, Guangzhou Medical University, Guangzhou, China
| | - Ruchong Chen
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Kefang Lai
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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Abstract
Chronic cough is a common condition, and generally affects about 3% of Korean adults with a significant influence on quality of life (QoL). Despite continued clinical and academic efforts, there are unmet needs for chronic cough prevention and management in Korea. Epidemiologically, there are two major challenges: an aging population and air pollution. Korea is one of the most rapidly aging countries, and the relative proportion of elderly to younger people is expected to double within the next two decades. Air pollution is a major concern, but there is very limited evidence on the effects of air pollutant on cough in Korean patients. Clinically, upper and lower airway diseases, such as rhinitis/rhinosinusitis and cough variant asthma/eosinophilic bronchitis, are reported to account for about 75% of chronic cough in Korean adults, which formed the basis in formulating clinical practice guidelines. However, further studies are warranted to resolve clinical uncertainty, particularly for the evaluation and treatment of upper airway conditions in chronic cough. The prevalence of gastroesophageal reflux disease (GERD) is increasing, thus its relevance to cough among Koreans may warrant re-evaluation. Infection-associated chronic cough, such as tuberculosis, is another continuing concern. The proportion of chronic refractory or unexplained cough is assumed to be 10–20% among patients visiting referral clinics for chronic cough. This review presents our perspectives on current epidemiological and clinical issues of chronic cough in Korea, and addresses major knowledge gaps and future research priorities.
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Affiliation(s)
- Ji-Hyang Lee
- Department of Allergy and Clinical Immunology, Airway Sensation and Cough Research Laboratory, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Woo-Jung Song
- Department of Allergy and Clinical Immunology, Airway Sensation and Cough Research Laboratory, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Campi G, Noale M, Fabbrizzi A, Lavorini F, Maggi S, Fontana G. The demographic and clinical characteristics of an Italian population of adult outpatients with chronic cough. Aging Clin Exp Res 2020; 32:741-746. [PMID: 31950437 DOI: 10.1007/s40520-019-01464-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/23/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Chronic cough is a major health problem worldwide and patients are best managed in specialised tertiary centres. Little information is available on the characteristics of chronic cough patients in several European countries, including Italy. AIMS We report on the demographic, anthropometric and clinical features of a large Italian population of adult chronic cough outpatients (about 1200), who were referred to a specialised clinic in Florence, Italy, from 2008 to 2018. METHODS Demographic, environmental, lifestyle and clinical information was collected at enrolment by means of a custom-designed electronic questionnaire that only allowed for uniform responses. A subjective measure of cough-related discomfort (cough score) was also obtained using a modified Borg Scale. A multivariable logistic regression model was defined to identify the patients' characteristics associated with the cough score. RESULTS The characteristics of the examined population (n = 1204 outpatients) were strikingly similar to those described elsewhere. Female patients outnumbered the males [n = 847 females, (70.0%)]; both females and males displayed the same average cough score. The median age of outpatients was 61 (quartile 1 = 48; quartile 3 = 70) years; age and cough duration were unrelated to the cough score. Nasal obstruction, coughing during consultation, coughing during meals, throat clearing and the presence of respiratory abnormalities were correlated with the degree of discomfort caused by coughing. DISCUSSION The features of chronic cough patients are similar worldwide. The process of cough reflex hypersensitisation may soothe sex-related perceptual differences, leading to similar levels of discomfort. CONCLUSIONS There seem to be clinical indicators that help in assessing the level of cough-related discomfort.
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Wallace E, Guiu Hernandez E, Ang A, Macrae P. Quantifying test-retest variability of natural and suppressed citric acid cough thresholds and urge to cough ratings. Pulm Pharmacol Ther 2019; 58:101838. [DOI: 10.1016/j.pupt.2019.101838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 11/25/2022]
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Wallace E, Guiu Hernandez E, Ang A, Hiew S, Macrae P. A systematic review of methods of citric acid cough reflex testing. Pulm Pharmacol Ther 2019; 58:101827. [PMID: 31326628 DOI: 10.1016/j.pupt.2019.101827] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION This systematic review summarises and appraises methods of citric acid cough reflex testing (CRT) documented in published literature. METHODS Electronic databases, MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus were searched up to and including 11th February 2018. Studies reporting a method of citric acid CRT, published in peer-reviewed journals in English or Spanish, were assessed for the inclusion criteria. Of the selected studies, information on the instrumentation and CRT protocol was extracted. RESULTS A total of 129 studies were included. Instrumentation and protocols differed widely across studies. Reporting of methods of citric acid CRT was sub-standard, with many crucial methodological components omitted from published manuscripts, preventing their full replication. CONCLUSIONS Considerable methodological variability exists for citric acid CRT in published literature. The findings suggest that caution is warranted in comparing citric acid cough thresholds across studies. Full replication of previously published methods of citric acid CRT is limited due to crucial elements of the citric acid CRT protocol being omitted from published manuscripts. These findings have implications on the use of citric acid CRT in clinical and pharmaceutical studies to evaluate the effects of antitussive medications and cough therapies.
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Affiliation(s)
- Emma Wallace
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand.
| | - Esther Guiu Hernandez
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Alicia Ang
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Sarah Hiew
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
| | - Phoebe Macrae
- University of Canterbury, Rose Centre for Stroke Recovery and Research, Dept of Communication Disorders, Christchurch, New Zealand
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Song WJ, Chang YS, Faruqi S, Kang MK, Kim JY, Kang MG, Kim S, Jo EJ, Lee SE, Kim MH, Plevkova J, Park HW, Cho SH, Morice AH. Defining Chronic Cough: A Systematic Review of the Epidemiological Literature. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2015; 8:146-55. [PMID: 26739408 PMCID: PMC4713878 DOI: 10.4168/aair.2016.8.2.146] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/09/2015] [Indexed: 01/29/2023]
Abstract
Purpose Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. Methods A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. Results A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I2=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity. Conclusions This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required.
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Affiliation(s)
- Woo Jung Song
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Yoon Seok Chang
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.,Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Shoaib Faruqi
- Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital, University of Hull, Cottingham, East Yorkshire, United Kingdom
| | - Min Koo Kang
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Ju Young Kim
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Min Gyu Kang
- Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Sujeong Kim
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
| | - Eun Jung Jo
- Department of Internal Medicine, Pusan National University College of Medicine, Busan, Korea
| | - Seung Eun Lee
- Department of Internal Medicine, Pusan National University College of Medicine, Busan, Korea
| | - Min Hye Kim
- Department of Internal Medicine, Ewha Woman's University School of Medicine, Seoul, Korea
| | - Jana Plevkova
- Department of Pathophysiology and Simulation Centre, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic
| | - Heung Woo Park
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Sang Heon Cho
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
| | - Alyn H Morice
- Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Castle Hill Hospital, University of Hull, Cottingham, East Yorkshire, United Kingdom.
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Morice AH, Jakes AD, Faruqi S, Birring SS, McGarvey L, Canning B, Smith JA, Parker SM, Chung KF, Lai K, Pavord ID, van den Berg J, Song WJ, Millqvist E, Farrell MJ, Mazzone SB, Dicpinigaitis P. A worldwide survey of chronic cough: a manifestation of enhanced somatosensory response. Eur Respir J 2014; 44:1149-55. [PMID: 25186267 DOI: 10.1183/09031936.00217813] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reports from individual centres suggest a preponderance of females with chronic cough. Females also have heightened cough reflex sensitivity. Here we have reviewed the age and sex of unselected referrals to 11 cough clinics. To investigate the cause of any observed sex dimorphism, functional magnetic resonance imaging of putative cough centres was analysed in normal volunteers. The demographic profile of consecutive patients presenting with chronic cough was evaluated. Cough challenge with capsaicin was undertaken in normal volunteers to construct a concentration-response curve. Subsequent functional magnetic resonance imaging during repeated inhalation of sub-tussive concentrations of capsaicin observed areas of activation within the brain and differences in the sexes identified. Of the 10,032 patients presenting with chronic cough, two-thirds (6591) were female (mean age 55 years). The patient profile was largely uniform across centres. The most common age for presentation was 60-69 years. The maximum tolerable dose of inhaled capsaicin was lower in females; however, a significantly greater activation of the somatosensory cortex was observed. Patients presenting with chronic cough from diverse racial and geographic backgrounds have a strikingly homogeneous demographic profile, suggesting a distinct clinical entity. The preponderance of females may be explained by sex-related differences in the central processing of cough sensation.
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Affiliation(s)
- Alyn H Morice
- Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK
| | - Adam D Jakes
- Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK
| | - Shoaib Faruqi
- Respiratory Medicine, Castle Hill Hospital, Centre for Cardiovascular and Metabolic Research, Hull York Medical School, Cottingham, UK
| | - Surinder S Birring
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Lorcan McGarvey
- Dept of Medicine, Institute of Clinical Science, The Queen's University of Belfast, Belfast, UK
| | - Brendan Canning
- Dept of Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, MD, USA
| | - Jaclyn A Smith
- Centre for Respiratory and Allergy, University of Manchester, University Hospital of South Manchester, Manchester, UK
| | - Sean M Parker
- Dept of Respiratory Medicine, North Tyneside General Hospital, Northumbria Healthcare NHSFT, North Shields, UK
| | - Kian Fan Chung
- Royal Brompton and Harefield NHS Trust and National Heart and Lung Institute, Imperial College, London, UK
| | - Kefang Lai
- Dept of Clinical Research, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
| | - Ian D Pavord
- Nuffield Dept of Medicine Research Building, University of Oxford, Oxford, UK
| | | | - Woo-Jung Song
- Dept of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea
| | - Eva Millqvist
- Dept of Internal Medicine/Respiratory Medicine and Allergology, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Michael J Farrell
- Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Stuart B Mazzone
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Peter Dicpinigaitis
- Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
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Monroe MD, Manco K, Bennett R, Huckabee ML. Citric acid cough reflex test: Establishing normative data. SPEECH LANGUAGE AND HEARING 2014. [DOI: 10.1179/2050572814y.0000000041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Weimer K, Gulewitsch MD, Schlarb AA, Schwille-Kiuntke J, Klosterhalfen S, Enck P. Placebo effects in children: a review. Pediatr Res 2013; 74:96-102. [PMID: 23598811 DOI: 10.1038/pr.2013.66] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 12/23/2012] [Indexed: 12/19/2022]
Abstract
Of more than 155,000 PubMed citations found with the search term "placebo," only ~9,000 (5.8%) included the terms "children" or "adolescents." When all these papers were screened, only ~2,000 of them investigated the placebo effect per se, and of those, only ~50 (2.5%) discussed the placebo effect in children and adolescents. In this narrative review, we explore four aspects of the placebo response in children and adolescents: (i) the legal and ethical limitations and restrictions for the inclusion of children in clinical trials as well as in experimental (placebo) research that may explain the poor knowledge base; (ii) the question of whether or not the placebo effect is larger in children and adolescents as compared with adults; (iii) whether the mechanisms underlying the placebo effect are similar between children and adults; and (iv) whether mediators and moderators of the placebo effect are comparable between children and adults. We finally discuss some of the consequences from the current placebo research in adults that may affect both experimental and clinical research in children and adolescents.
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Affiliation(s)
- Katja Weimer
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital TĂĽbingen, TĂĽbingen, Germany.
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11
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Comparison of cough reflex test against instrumental assessment of aspiration. Physiol Behav 2013; 118:25-31. [DOI: 10.1016/j.physbeh.2013.05.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 04/21/2013] [Accepted: 05/05/2013] [Indexed: 11/20/2022]
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12
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Dickinson GL, Rezaee S, Proctor NJ, Lennard MS, Tucker GT, Rostami-Hodjegan A. Incorporating In Vitro Information on Drug Metabolism Into Clinical Trial Simulations to Assess the Effect of CYP2D6 Polymorphism on Pharmacokinetics and Pharmacodynamics: Dextromethorphan as a Model Application. J Clin Pharmacol 2013; 47:175-86. [PMID: 17244768 DOI: 10.1177/0091270006294279] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In vitro-in vivo extrapolation of clearance, embedded in a clinical trial simulation, was used to investigate differences in the pharmacokinetics and pharmacodynamics of dextromethorphan between CYP2D6 poor and extensive metabolizer phenotypes. Information on the genetic variation of CYP2D6, as well as the in vitro metabolism and pharmacodynamics of dextromethorphan and its active metabolite dextrorphan, was integrated to assess the power of studies to detect differences between phenotypes. Whereas 6 subjects of each phenotype were adequate to achieve 80% power in showing pharmacokinetic differences, the power required to detect a difference in antitussive response was less than 80% with 500 subjects in each study arm. Combining in vitro-in vivo extrapolation with a clinical trial simulation is useful in assessing different elements of study design and could be used a priori to avoid inconclusive pharmacogenetic studies.
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Affiliation(s)
- Gemma L Dickinson
- Academic Unit of Clinical Pharmacology, School of Medicine, University of Sheffield, M-floor, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF, UK
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Faruqi S, Molyneux ID, Fathi H, Wright C, Thompson R, Morice AH. Chronic cough and esomeprazole: a double-blind placebo-controlled parallel study. Respirology 2012; 16:1150-6. [PMID: 21707852 DOI: 10.1111/j.1440-1843.2011.02014.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND OBJECTIVE Gastro-oesophageal reflux has been implicated in the pathogenesis of chronic cough. Guidelines on management suggest a therapeutic trial of anti-reflux medication. Esomeprazole is a proton pump inhibitor licensed for the long-term treatment of acid reflux in adults and we compared the effects of esomeprazole and placebo on patients with chronic cough. METHODS This was a prospective, single-centre, randomized, double-blind, placebo-controlled, parallel group study conducted over 8weeks. Fifty adult non-smokers with chronic cough and normal spirometry were randomized. Patients completed cough-related quality-of-life and symptom questionnaires and subjective scores of cough frequency and severity at the beginning and end of the study. They also kept a daily diary of symptom scores. Citric acid cough challenge and laryngoscopic examination were performed at baseline and the end of the study. The primary outcome was improvement in cough score. RESULTS There were no differences in cough scores in the placebo and treatment arms of the study although some significant improvements were noted when compared to baseline. In the cough diary scores there was a trend towards greater improvement in the treatment arm in patients with dyspepsia. CONCLUSIONS Esomeprazole did not have a clinically important effect greater than placebo in patients with cough. It suggests a marked placebo effect in the treatment of cough.
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Affiliation(s)
- Shoaib Faruqi
- Division of Cardiovascular and Respiratory Studies, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, UK.
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14
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Wright CE, Jackson J, Thompson RL, Morice AH. Validation of the ERS standard citric acid cough challenge in healthy adult volunteers. COUGH 2010; 6:8. [PMID: 20698995 PMCID: PMC2925329 DOI: 10.1186/1745-9974-6-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 08/10/2010] [Indexed: 11/10/2022]
Abstract
UNLABELLED Protocols measuring cough sensitivity can vary in terms of nebuliser, tussive agent, single and dose response. A definitive method for measuring cough sensitivity needs to be established.The ERS guidelines recommend the KoKo DigiDoser (KD) delivery system. Study aim, was to compare the reproducibility of this citric acid (CA) cough challenge and previously established Mefar dosimeter (MD) protocol.39 (female 26) volunteers mean age (40.4 yrs) were randomised to either KD or MD. Intra-day and inter-day reproducibility was compared.We calculated the concentration of citric acid evoking 2 coughs (C2).The geometric mean C2 (95%CI) was similar for both KD and MD, of 263 (200,339) mM and 209 (151,288) mM respectively.The mean KD C2 was not significantly different. (F = 0.807, p = 0.93) from baseline over 1, 2, and 4 hrs however, the MD demonstrated significant variability (F = 7.85, P < 0.001)Measuring mean log C2 at baseline and at 2 weeks, the KD demonstrated a stronger intraclass correlation of log C2 at baseline with 2 week log C2, ICC = 0.70 than was shown with the Mefar, ICC = 0.41Administering CA from KD offers a reproducible cough challenge in healthy volunteers. The results correlate well with the MD challenge but offer greater intra-day and inter-day reproducibility. TRIAL REGISTRATION Current controlled trials ISRCTN98385033.
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Affiliation(s)
- Caroline E Wright
- Division of Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, UK
| | - Jennifer Jackson
- Division of Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, UK
| | - Rachel L Thompson
- Division of Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, UK
| | - Alyn H Morice
- Division of Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, UK
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15
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Eccles R. Importance of placebo effect in cough clinical trials. Lung 2009; 188 Suppl 1:S53-61. [PMID: 19760296 DOI: 10.1007/s00408-009-9173-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 08/24/2009] [Indexed: 01/31/2023]
Abstract
Cough is a unique symptom because, unlike sneeze and other symptoms, it can be under voluntary control and this complicates clinical trials on cough medicines. All over-the-counter cough medicines (OTC) are very effective treatments because of their placebo effect. The placebo effect is enhanced by expectancy related to advertising, brand, packaging, and formulation. This placebo effect creates a problem for the conduct of clinical trials on OTC cough medicines that attempt to demonstrate the efficacy of a pharmacological agent above that of any placebo effect. Up to 85% of the efficacy of some cough medicines can be attributed to a placebo effect. The placebo effect apparent in clinical trials consists of several components: natural recovery, regression of cough response toward mean, demulcent effect, effect of sweetness, voluntary control, and effects related to expectancy and meaning of the treatment. The placebo effect has been studied most in the pain model, and placebo analgesia is reported to depend on the activation of endogenous opioid systems in the brain; this model may be applicable to cough. A balanced placebo design may help to control for the placebo effect, but this trial design may not be acceptable due to deception of patients. The placebo effect in clinical trials may be controlled by use of a crossover design, where feasible, and the changes in the magnitude of the placebo effect in this study design are discussed.
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Affiliation(s)
- Ron Eccles
- Common Cold Centre, Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, Wales, UK,
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Abstract
As interest in clinical cough research grows, measurement of cough reflex sensitivity will assume an increasingly important role. With proper equipment and meticulous attention to methodological details, cough reflex sensitivity can be safely, accurately, and reproducibly determined. Such precise measurement allows the evaluation of the effect of pharmacological or nonpharmacological interventions on the sensitivity of the cough reflex, or the comparison of cough reflex sensitivity between different subject populations. In addition to the method, other vital components of optimal cough challenge testing include proper interpretation of data and appropriate selection of study populations.
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Ramsay J, Wright C, Thompson R, Hull D, Morice AH. Assessment of antitussive efficacy of dextromethorphan in smoking related cough: objective vs. subjective measures. Br J Clin Pharmacol 2008; 65:737-41. [PMID: 18279476 DOI: 10.1111/j.1365-2125.2008.03115.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Dextromethorphan is widely used as a cough suppressant in over the counter medications. Its efficacy in altering cough reflex sensitivity has been shown in healthy volunteers. In contrast evidence for an effect on clinically important cough is poor. WHAT THIS STUDY ADDS A significant decrease in evoked cough was seen with dextromethorphan compared with placebo. However, both placebo and active treatment improved subjective data to a similar degree. We doubt the validity of currently used objective tests in the investigation of antitussives. AIMS Using an established model of smokers cough we measured the antitussive effects of dextromethorphan compared with placebo. METHODS The study was a randomized, double-blind placebo controlled, crossover comparison of 22 mg 0.8 ml(-1) dextromethorphan delivered pregastrically with matched placebo. Objective and subjective measurements of cough were recorded. Subjective measures included a daily diary record of cough symptoms and the Leicester quality of life questionnaire. Cough frequency was recorded using a manual cough counter. The objective measure of cough reflex sensitivity was the citric acid, dose-response cough challenge. RESULTS Dextromethorphan was significantly associated with an increase in the concentration of citric acid eliciting an average of two coughs/inhalation (C2) when compared with placebo, 1 h post dose by 0.49 mM (95% CI 0.05, 0.45, geometric mean 3.09) compared with placebo 0.24 mM (geometric mean 1.74) P < 0.05 and at 2 h 0.57 mM (95% CI 0.01, 0.43, geometric mean 3.75) compared with placebo 0.34 mM (geometric mean 2.19) P < 0.05). There was a highly significant improvement in the subjective data when compared with baseline. However, there was no significant difference between placebo and active treatment. No correlation was seen between cough sensitivity to citric acid and recorded cough counts or symptoms. When both subjective and objective data were compared with screening data there was evidence of a marked 'placebo' effect. CONCLUSIONS The objective measure of cough sensitivity demonstrates dextromethorphan effectively diminishes the cough reflex sensitivity. However, subjective measures do not support this. Other studies support these findings, which may represent a profound sensitivity of the cough reflex to higher influences.
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Affiliation(s)
- James Ramsay
- University of Hull, Cardiovascular and Respiratory Studies, Castle Hill Hospital, Cottingham, East Yorkshire, UK
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18
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Abstract
The experimental induction of cough has become an important component of clinical cough research. Measurement of cough reflex sensitivity allows the evaluation of the effect of pharmacological and other interventions on the cough reflex, as well as the performance of epidemiological studies relevant to cough. The most commonly used tussive agents include capsaicin, citric acid and ultrasonically nebulized distilled water (fog). Methodological considerations are vital to the performance of high quality, reproducible cough challenge, which is especially important when measuring the effect of an experimental intervention on cough reflex sensitivity. For the optimal execution of clinical trials employing inhalation cough challenge, the subject population must be carefully selected, and the usefulness and potential limitations of data obtained from cough challenge studies need to be appreciated.
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Affiliation(s)
- Peter V Dicpinigaitis
- Albert Einstein College of Medicine and Montefiore Medical Center, 1825 Eastchester Road, Bronx, New York, USA.
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Sievenpiper JL, Ezatagha A, Dascalu A, Vuksan V. When a placebo is not a 'placebo': a placebo effect on postprandial glycaemia. Br J Clin Pharmacol 2007; 64:546-9. [PMID: 17509038 PMCID: PMC2048544 DOI: 10.1111/j.1365-2125.2007.02929.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS Placebo effects in clinical trials remain uncertain. To investigate a placebo effect on acute postprandial plasma glucose, we conducted a follow-up investigation on a previous study. METHODS The effect of placebo (9 g encapsulated cornstarch +500 ml water, taken at -40 min) on the plasma glucose response to a 75-g oral glucose tolerance test (OGTT) was assessed in a previous study in 12 healthy subjects (gender, five male, seven female; age 27 +/- 6 years; body mass index 24 +/- 3.4 kg m(-2)). This was compared with the effect of a water control (500 ml water taken alone at -40 min) on the same outcome in the same subjects in a follow-up study. RESULTS Cornstarch placebo decreased plasma glucose area under the curve during the 75-g OGTT by 28% [Delta (95% confidence interval) -63.3 min mmol(-1) l(-1) (-218.33, 91.66), P < 0.02] compared with the water control (P < 0.05). CONCLUSIONS Postprandial plasma glucose outcomes may be vulnerable to placebo effects.
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Affiliation(s)
- John L Sievenpiper
- Risk Factor Modification Centre, St Michael's Hospital and Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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20
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Morice AH, Menon MS, Mulrennan SA, Everett CF, Wright C, Jackson J, Thompson R. Opiate therapy in chronic cough. Am J Respir Crit Care Med 2006; 175:312-5. [PMID: 17122382 DOI: 10.1164/rccm.200607-892oc] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Cough is the most common complaint for which medical attention is sought, and chronic cough can be both physically and mentally debilitating. There is currently no evidence supporting the use of antitussives in chronic treatment-resistant cough. OBJECTIVES We tested the hypothesis that morphine sulfate in the dose of 5 mg twice daily would bring about a reduction in cough frequency and severity in patients failing to respond to specific measures. METHODS Patients recruited from the Hull Cough Clinic were enrolled into a randomized double-blind placebo-controlled study using 4 weeks of slow-release morphine sulfate and a corresponding period of matched placebo. An open-labeled extension of the core study allowed dose escalation to 10 mg twice daily. Cough was assessed using the Leicester Cough Questionnaire, daily symptom diary, and citric acid cough challenge. RESULTS Twenty-seven patients completed the core study. A significant improvement of 3.2 points over baseline was noted on the Leicester Cough Questionnaire (p < 0.01). A rapid and highly significant reduction by 40% in daily cough scores was noted among patients on slow-release morphine sulfate (p < 0.01). Objective testing of the cough reflex using citric acid cough challenge tests did not show any significant changes. Eighteen patients continued into the extension study. Two-thirds of these patients opted to increase the morphine to 10 mg twice daily. At the end of 3 months, there was a similar improvement in cough between the 5- and 10-mg groups. CONCLUSION Morphine sulfate is an effective antitussive in intractable chronic cough at the doses of 5 to 10 mg twice daily.
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Affiliation(s)
- Alyn H Morice
- Department of Academic Medicine, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK.
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McGarvey LPA, Morice AH. Clinical cough and its mechanisms. Respir Physiol Neurobiol 2006; 152:363-71. [PMID: 16406741 DOI: 10.1016/j.resp.2005.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 11/18/2005] [Accepted: 11/22/2005] [Indexed: 11/22/2022]
Abstract
Cough is the commonest symptom of clinical importance and the most frequent reason for new consultations with a doctor. Although therapy directed at any underlying cause for cough can be effective there is a clinical need for new treatments specifically directed at the cough itself. A major obstacle to the development of such therapy has been an imprecise understanding of the pathophysiological mechanisms responsible for cough. In this article, we review the important clinical aspects of both acute and chronic cough, offer practical insight into the existing treatment options, highlight the current understanding of cough pathophysiology and identify important areas for future research effort.
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Affiliation(s)
- L P A McGarvey
- Department of Medicine, The Queen's University of Belfast, Grosvenor Road, Belfast BT12 6BJ, N Ireland, UK.
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Klosterhalfen S, Kellermann S, Stockhorst U, Wolf J, Kirschbaum C, Hall G, Enck P. Latent inhibition of rotation chair-induced nausea in healthy male and female volunteers. Psychosom Med 2005; 67:335-40. [PMID: 15784802 DOI: 10.1097/01.psy.0000156930.00201.e0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Pre-exposure to an environment in which a nausea-inducing body rotation will subsequently be given constitutes a latent inhibition procedure that might act to reduce anticipatory and postrotation nausea. METHODS This was tested in 24 healthy subjects randomly assigned to receive no pre-exposure (group 0), a single pre-exposure (group 1), or three pre-exposures (group 3). Rotation was standardized as 5 x 1 minute rotation, but the subjects could terminate it on request. Nausea was determined on a 7-item symptom rating scale before, during, and after rotation on days 3 and 4, whereas anticipatory nausea was measured before presumed rotation on day 5. Saliva cortisol and tumor necrosis factor alpha (TNF-alpha) levels were determined at baseline before, directly, and 15 and 30 minutes after rotation every day, and before presumed rotation on day 5. RESULTS Pre-exposure significantly reduced the degree of anticipatory nausea on day 5. Cortisol levels increased with rotation and were higher at baseline on days 4 and 5, but subjects habituated from day 3 to day 4; levels were lower in women than in men. In contrast, TNF-alpha decreased with rotation but showed no habituation. For both cortisol and TNF-alpha, no effects on postrotational nausea were found. CONCLUSION It is concluded that repetitive pre-exposure (latent inhibition) reduces anticipatory but not postrotation nausea; behavioral measures (rotation time) and measures of acute stress (cortisol, TNF-alpha) do not respond to latent inhibition. Thus, Pavlovian conditioning rules are effective in healthy humans with anticipatory nausea but not with postrotation nausea. Hormonal responses--TNF-alpha decrease with stress, compensatory cortisol increase--and gender-related effects on learning and habituation are discussed with regard to psychophysiological and psychoimmunological processes.
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Affiliation(s)
- Sibylle Klosterhalfen
- Institute of Medical Psychology, University Hospitals DĂĽsseldorf, DĂĽsseldorf, Germany
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Ebihara S, Saito H, Kanda A, Nakajoh M, Takahashi H, Arai H, Sasaki H. Impaired efficacy of cough in patients with Parkinson disease. Chest 2003; 124:1009-15. [PMID: 12970031 DOI: 10.1378/chest.124.3.1009] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
STUDY OBJECTIVES Aspiration pneumonia, a leading cause of death in patients with Parkinson disease (PD), usually occurs at the advanced stages of the disease. We investigated both motor and sensory components of cough and induced-sputum substance P (SP) concentrations in patients with early and advanced stages of PD to assess whether cough efficacy is impaired in PD. SUBJECTS Fifteen female patients with early stages of PD (Hoehn and Yahr stage II-III), 10 patients with advanced stages of PD (Hoehn and Yahr stage IV), and 15 age-matched female control subjects were investigated. MEASUREMENTS The motor component of cough efficacy was assessed by monitoring voluntary maximal cough peak flow. The sensory component of cough efficacy was assessed by measuring cough reflex sensitivity to citric acid inhalation. Sputum SP concentrations were measured in sputum induced by hypertonic saline solution inhalation. RESULTS The mean (+/- SD) cough peak flow rates in patients with both early PD (230 +/- 74 L/min; p < 0.005) and advanced PD (186 +/- 60 L/min; p < 0.0001) were significantly weaker than that in control subjects (316 +/- 70 L/min). Cough reflex sensitivity in patients with advanced PD (46.7 +/- 49.3 g/L) was significantly lower compared to control subjects (14.5 +/- 16.6 g/L; p < 0.01) and patients with early PD (11.2 +/- 14.8 g/L; p < 0.005). The sputum SP concentration was significantly lower in patients with advanced PD (11.2 +/- 8.4 pg/mL) compared to that in control subjects (35.6 +/- 15.4 pg/mL) and patients with early PD (28.5 +/- 16.4 pg/mL). CONCLUSION In the early stages of the disease, mainly the motor component of cough was impaired. In advanced stages of the disease, both the motor and sensory components of cough were impaired. Sputum SP concentration significantly declined in patients with advanced PD. The results suggest that the combination of impaired motor and sensory components of cough may play an important role in the development of aspiration pneumonia in PD.
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Affiliation(s)
- Satoru Ebihara
- Department of Geriatric and Respiratory Medicine, Tohoku University School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan
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Moghadamnia AA, Rostami-Hodjegan A, Abdul-Manap R, Wright CE, Morice AH, Tucker GT. Physiologically based modelling of inhibition of metabolism and assessment of the relative potency of drug and metabolite: dextromethorphan vs. dextrorphan using quinidine inhibition. Br J Clin Pharmacol 2003; 56:57-67. [PMID: 12848776 PMCID: PMC1884341 DOI: 10.1046/j.1365-2125.2003.01853.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To define the relative antitussive effect of dextromethorphan (DEX) and its primary metabolite dextrorphan (DOR) after administration of DEX. METHODS Data were analysed from a double-blind, randomized cross-over study in which 22 subjects received the following oral treatments: (i) placebo; (ii) 30 mg DEX hydro-bromide; (iii) 60 mg DEX hydro-bromide; and (iv) 30 mg DEX hydro-bromide preceded at 1 h by quinidine HCl (50 mg). Cough was elicited using citric acid challenge. Pharmacokinetic data from all non-placebo arms of the study were fitted simultaneously. The parameters were then used as covariates in a link PK-PD model of cough suppression using data from all treatment arms. RESULTS The best-fit PK model assumed two- and one-compartment PK models for DEX and DOR, respectively, and competitive inhibition of DEX metabolism by quinidine. The intrinsic clearance of DEX estimated from the model ranged from 59 to 1536 l x h(-1), which overlapped with that extrapolated from in vitro data (12-261 l x h(-1)) and showed similar variation (26- vs. 21-fold, respectively). The inhibitory effect of quinidine ([I]/Ki) was 19 (95% confidence interval of mean: 18-20) with an estimated average Ki of 0.017 microM. Although DEX and DOR were both active, the potency of the antitussive effect of DOR was 38% that of DEX. A sustained antitussive effect was related to slow removal of DEX/DOR from the effect site (ke0 = 0.07 h(-1)). CONCLUSIONS Physiologically based PK modelling with perturbation of metabolism using an inhibitor allowed evaluation of the antitussive potency of DOR without the need for separate administration of DOR.
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Affiliation(s)
- A A Moghadamnia
- Molecular Pharmacology & Pharmacogenetics, Division of Clinical Sciences (South), University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK
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Affiliation(s)
- A H Morice
- Academic Department of Medicine, Respiratory Medicine, University of Hull, Castle Hill Hospital, Castle Road, Cottingham HU16 5JQ.
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