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Wallace E, Guiu Hernandez E, Epton M, Ploen L, Huckabee ML, Macrae P. A Sensory Stimulation Protocol to Modulate Cough Sensitivity: A Randomized Controlled Trial Safety Study. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2020; 29:1423-1433. [PMID: 32379483 DOI: 10.1044/2020_ajslp-19-00180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose This study evaluated the safety and efficacy of a sensory stimulation protocol that was designed to modulate citric acid cough thresholds as a potential treatment for silent aspiration. Method Healthy adults (n = 24) were randomly assigned to one of three sensory stimulation groups: (a) high-intensity ultrasonically nebulized distilled water (UNDW) inhalations (1.6 ml/min); (b) low-intensity UNDW inhalations (0.5 ml/min); and (3) control, 0.9% saline inhalations (1.6 ml/min). Sensory stimulation was delivered once a day, for 4 consecutive days. Citric acid cough thresholds were determined at baseline, Day 3, and Day 5 to evaluate changes in cough sensitivity. Spirometry was undertaken before, during, and after each sensory stimulation session to monitor for bronchoconstriction. Results No participant showed evidence of bronchoconstriction during the sensory stimulation protocol. There was an interaction effect between day and group on suppressed cough thresholds, χ2(4) = 11.32, p = .02. When compared to the control group, there was a decrease in citric acid cough thresholds across Days 1-5 in the high-intensity (-1.8 doubling concentrations, 95% confidence interval [-2.88, -0.72], p = .01) and low-intensity (-1.3 doubling concentrations, 95% confidence interval [-2.4, -0.2], p = .03) UNDW inhalation groups, representing a sensitization effect of UNDW inhalations on cough sensitivity. Conclusions The UNDW sensory stimulation protocol was safe in healthy adults. The findings provide preliminary evidence that UNDW inhalations sensitize laryngeal afferents related to citric acid-induced cough induction. The therapeutic potential of the UNDW sensory stimulation protocol will be explored in patients with reduced cough sensitivity who are at risk of silent aspiration and aspiration pneumonia. Plain Language Summary This study explored the safety and efficacy of a sensory stimulation protocol that was designed to modulate cough sensitivity as a potential treatment for silent aspiration. The study revealed that inhalations of nebulized distilled water were safe and increased cough sensitivity, when compared to control saline inhalations.
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Affiliation(s)
- Emma Wallace
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Esther Guiu Hernandez
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Michael Epton
- Canterbury Respiratory Research Group, Christchurch Hospital, New Zealand
| | - Laura Ploen
- Respiratory Physiology Laboratory, Christchurch Hospital, New Zealand
| | - Maggie-Lee Huckabee
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
| | - Phoebe Macrae
- Department of Communication Disorders, Rose Centre for Stroke Recovery and Research, University of Canterbury, Christchurch, New Zealand
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Silva AR, Dinis-Oliveira RJ. Pharmacokinetics and pharmacodynamics of dextromethorphan: clinical and forensic aspects. Drug Metab Rev 2020; 52:258-282. [DOI: 10.1080/03602532.2020.1758712] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Ana Rita Silva
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Ricardo Jorge Dinis-Oliveira
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, Porto, Portugal
- Department of Sciences, IINFACTS – Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, Gandra, Portugal
- Department of Biological Sciences, Faculty of Pharmacy, Laboratory of Toxicology, UCIBIO, REQUIMTE, University of Porto, Porto, Portugal
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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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Faruqi S, Wright C, Thompson R, Morice AH. A randomized placebo controlled trial to evaluate the effects of butamirate and dextromethorphan on capsaicin induced cough in healthy volunteers. Br J Clin Pharmacol 2015; 78:1272-80. [PMID: 24995954 DOI: 10.1111/bcp.12458] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 06/27/2014] [Indexed: 11/27/2022] Open
Abstract
AIMS The examination of cough reflex sensitivity through inhalational challenge can be utilized to demonstrate pharmacological end points. Here we compare the effect of butamirate, dextromethorphan and placebo on capsaicin-induced cough in healthy volunteers. METHODS In this randomized, placebo-controlled, six way crossover study the effect of dextromethrophan 30 mg, four doses of butamirate and placebo was evaluated on incremental capsaicin challenges performed at baseline and 2, 4, 6, 8, 12 and 24 h following dosing. The primary end point was the area under the curve (AUC(0,12h)) of log10 C5 from pre-dose to 12 h after dosing. Plasma butamirate metabolites were analyzed to evaluate pharmacokinetic and pharmacodynamic relationships. RESULTS Thirty-four subjects (13 males, median age 25 years) completed the study. Cough sensitivity decreased from baseline in all arms of the study. Dextromethorphan was superior to placebo (P = 0.01) but butamirate failed to show significant activity with maximum attenuation at the 45 mg dose. There was no apparent relationship between pharmacokinetic and pharmacodynamic parameters for butamirate. CONCLUSIONS We have demonstrated for the first time that dextromethorphan attenuates capsaicin challenge confirming its broad activity on the cough reflex. The lack of efficacy of butamirate could be due to formulation issues at higher doses.
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Affiliation(s)
- Shoaib Faruqi
- Department of Cardiovascular and Respiratory Studies, University of Hull and Hull York Medical School, Castle Hill Hospital, Cottingham, HU16 5JQ, UK
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Morice AH. Over-the-counter cough medicines: New approaches. Pulm Pharmacol Ther 2015; 35:149-51. [PMID: 26232720 DOI: 10.1016/j.pupt.2015.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/14/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
The global market for over-the-counter (OTC) medicines in the category cough/cold is enormous amounting to 5.77 billion euro in 2014 (source IMS). Despite this enormous healthcare investment, mainly by direct consumer purchase, evidence for efficacy is poor by modern standards. Because of a lack of new drug development existing OTC medicines are supported by trials of inadequate design. This has led to the claim that cough medicines are inefficacious. Recent developments in measuring cough support some existing agents but investment in modern studies to provide comprehensive proof of efficacy has not happened. The switch from prescription medicine to OTC which has occurred in other markets will not occur in antitussives since novel therapies have yet to be developed. One area, that of herbal derived medicines, has seen innovation because it is less hampered by regulatory constraints.
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Affiliation(s)
- Alyn H Morice
- Centre for Cardiovascular & Metabolic Research, HYMS, University of Hull, Castle Hill Hospital, Castle Road, Cottingham, East Yorkshire, HU16 5JQ, UK.
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Boulet LP, Coeytaux RR, McCrory DC, French CT, Chang AB, Birring SS, Smith J, Diekemper RL, Rubin B, Irwin RS. Tools for assessing outcomes in studies of chronic cough: CHEST guideline and expert panel report. Chest 2015; 147:804-814. [PMID: 25522203 PMCID: PMC5991766 DOI: 10.1378/chest.14-2506] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Since the publication of the 2006 American College of Chest Physicians (CHEST) cough guidelines, a variety of tools has been developed or further refined for assessing cough. The purpose of the present committee was to evaluate instruments used by investigators performing clinical research on chronic cough. The specific aims were to (1) assess the performance of tools designed to measure cough frequency, severity, and impact in adults, adolescents, and children with chronic cough and (2) make recommendations or suggestions related to these findings. METHODS By following the CHEST methodologic guidelines, the CHEST Expert Cough Panel based its recommendations and suggestions on a recently published comparative effectiveness review commissioned by the US Agency for Healthcare Research and Quality, a corresponding summary published in CHEST, and an updated systematic review through November 2013. Recommendations or suggestions based on these data were discussed, graded, and voted on during a meeting of the Expert Cough Panel. RESULTS We recommend for adults, adolescents (≥ 14 years of age), and children complaining of chronic cough that validated and reliable health-related quality-of-life (QoL) questionnaires be used as the measurement of choice to assess the impact of cough, such as the Leicester Cough Questionnaire and the Cough-Specific Quality-of-Life Questionnaire in adult and adolescent patients and the Parent Cough-Specific Quality of Life Questionnaire in children. We recommend acoustic cough counting to assess cough frequency but not cough severity. Limited data exist regarding the performance of visual analog scales, numeric rating scales, and tussigenic challenges. CONCLUSIONS Validated and reliable cough-specific health-related QoL questionnaires are recommended as the measurement of choice to assess the impact of cough on patients. How they compare is yet to be determined. When used, the reporting of cough severity by visual analog or numeric rating scales should be standardized. Previously validated QoL questionnaires or other cough assessments should not be modified unless the new version has been shown to be reliable and valid. Finally, in research settings, tussigenic challenges play a role in understanding mechanisms of cough.
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Key Words
- ahrq, agency for healthcare research and quality
- cb, consensus-based
- cer, comparative effectiveness review
- chest, american college of chest physicians
- coi, conflict of interest
- cqlq, cough-specific quality-of-life questionnaire
- lcq, leicester cough questionnaire
- pcq, pediatric cough questionnaire
- pc-qol, parent cough-specific quality of life questionnaire
- picots, population of interest, interventions, comparators, outcomes, timing of outcomes, and settings
- qol, quality of life
- vas, visual analog scale
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Affiliation(s)
- Louis-Philippe Boulet
- Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada.
| | - Remy R Coeytaux
- Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC
| | - Douglas C McCrory
- Duke Evidence-based Practice Center, Duke Clinical Research Institute, Duke University, Durham, NC
| | - Cynthia T French
- Pulmonary, Allergy and Critical Care Medicine, UMass Memorial Medical Center, Worcester, MA
| | - Anne B Chang
- Department of Respiratory Medicine, Royal Children's Hospital, Herston, QLD, Australia
| | - Surinder S Birring
- Division of Asthma, Allergy and Lung Biology, King's College London, London, England
| | - Jaclyn Smith
- University Hospital of South Manchester, Manchester, England
| | | | - Bruce Rubin
- Virginia Commonwealth University, Richmond, VA
| | - Richard S Irwin
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Massachusetts Medical School, Worcester, MA
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Dickinson RS, Morjaria JB, Wright CE, Morice AH. Is opiate action in cough due to sedation? Ther Adv Chronic Dis 2014; 5:200-5. [PMID: 25177477 DOI: 10.1177/2040622314543220] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Opiates have been used for cough suppression for centuries. It is unclear whether this antitussive action is due to their known sedative effects. We aimed to assess correlation between cough suppression and opiate usage. METHODS We performed a post hoc analysis of two published trials with three opioids. In study one, patients with chronic cough were treated with 4 weeks of modified release morphine sulphate (5 mg twice daily) or placebo in a double-blinded placebo-controlled fashion. Cough suppression was assessed subjectively by the Leicester Cough Questionnaire and objectively by citric acid aerosol (CAA) induced cough challenge. In study 2, normal volunteers were given single doses of placebo, codeine 30 mg or dextromethorphan 50 mg and cough suppression assessed using the CAA-induced cough challenge. Sedation was contemporaneously assessed by direct questioning. RESULTS There were 14 episodes of patient-reported sedation; 2 with modified release morphine sulphate, 9 with codeine and 3 with dextromethorphan. There was no correlation between change in the Leicester Cough Questionnaire or the CAA-induced cough challenge and reported sedation. CONCLUSION This observational study suggests that sedation is unlikely to underlie the antitussive properties of these opioids. Eliciting the mechanism of these medications in cough may be a target for future tailored drug development.
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Affiliation(s)
- Rebecca S Dickinson
- Academic Department of Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, UK
| | - Jaymin B Morjaria
- Academic Department of Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, UK
| | - Caroline E Wright
- Academic Department of Respiratory Medicine, Hull York Medical School, University of Hull, Castle Hill Hospital, Cottingham, UK
| | - Alyn H Morice
- Main Administration Building, Castle Hill Hospital, Castle Road, Cottingham HU16 5JQ, UK
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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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Nilius B, Szallasi A. Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine. Pharmacol Rev 2014; 66:676-814. [DOI: 10.1124/pr.113.008268] [Citation(s) in RCA: 348] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Dicpinigaitis PV, Morice AH, Birring SS, McGarvey L, Smith JA, Canning BJ, Page CP. Antitussive drugs--past, present, and future. Pharmacol Rev 2014; 66:468-512. [PMID: 24671376 PMCID: PMC11060423 DOI: 10.1124/pr.111.005116] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cough remains a serious unmet clinical problem, both as a symptom of a range of other conditions such as asthma, chronic obstructive pulmonary disease, gastroesophageal reflux, and as a problem in its own right in patients with chronic cough of unknown origin. This article reviews our current understanding of the pathogenesis of cough and the hypertussive state characterizing a number of diseases as well as reviewing the evidence for the different classes of antitussive drug currently in clinical use. For completeness, the review also discusses a number of major drug classes often clinically used to treat cough but that are not generally classified as antitussive drugs. We also reviewed a number of drug classes in various stages of development as antitussive drugs. Perhaps surprising for drugs used to treat such a common symptom, there is a paucity of well-controlled clinical studies documenting evidence for the use of many of the drug classes in use today, particularly those available over the counter. Nonetheless, there has been a considerable increase in our understanding of the cough reflex over the last decade that has led to a number of promising new targets for antitussive drugs being identified and thus giving some hope of new drugs being available in the not too distant future for the treatment of this often debilitating symptom.
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Affiliation(s)
- P V Dicpinigaitis
- King's College London, Franklin Wilkins Building, 100 Stamford St., London, SE1 9NH, UK.
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Yancy WS, McCrory DC, Coeytaux RR, Schmit KM, Kemper AR, Goode A, Hasselblad V, Heidenfelder BL, Sanders GD. Efficacy and tolerability of treatments for chronic cough: a systematic review and meta-analysis. Chest 2014; 144:1827-1838. [PMID: 23928798 DOI: 10.1378/chest.13-0490] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Understanding the comparative effectiveness of treatments for patients with unexplained or refractory cough is important to increase awareness of proven therapies and their potential adverse effects in this unique population. METHODS We performed a literature search for English-language studies published up to June 2012 that compared symptomatic therapies for chronic cough. Two investigators screened each abstract and full-text article for inclusion, abstracted data, and rated quality. Meta-analysis with random-effects models was used to summarize effects of treatments. RESULTS We identified 49 studies (3,067 patients) comprising 68 therapeutic comparisons. Of the studied agents, opioid and certain nonopioid and nonanesthetic antitussives had demonstrated efficacy for chronic cough in adults. Compared with placebo, effect sizes (standardized mean differences for cough severity and rate ratios for cough frequency) for opioids were 0.55 (95% CI, 0.38-0.72; P < .0001) and 0.57 (95% CI, 0.36-0.91; P = .0260), respectively. For dextromethorphan, effect sizes were 0.37 (95% CI, 0.19-0.56; P = .0008) and 0.40 (95% CI, 0.18-0.85; P = .0248), respectively. The overall strength of evidence was limited by inconsistency and imprecision of results and by small numbers of direct comparisons. Nonpharmacologic therapies and the management of cough in children were infrequently studied. CONCLUSIONS Although evidence is limited, opioid and certain nonopioid and nonanesthetic antitussives demonstrated efficacy for treating chronic cough in adults. There is a need for further studies in patients with unexplained or refractory cough as well as for more systematic study designs, assessment of patient-centered outcomes, and reporting.
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Affiliation(s)
- William S Yancy
- Department of Medicine, Duke University School of Medicine, Durham, NC; Center for Health Services Research in Primary Care, Veterans Affairs Medical Center, Durham, NC.
| | - Douglas C McCrory
- Department of Medicine, Duke University School of Medicine, Durham, NC; Center for Health Services Research in Primary Care, Veterans Affairs Medical Center, Durham, NC; Duke Evidence-based Practice Center, Duke Clinical Research Institute, Durham, NC
| | - Remy R Coeytaux
- Doctor of Physical Therapy Division, Duke University School of Medicine, Durham, NC; Duke Evidence-based Practice Center, Duke Clinical Research Institute, Durham, NC
| | - Kristine M Schmit
- Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC
| | - Alex R Kemper
- Department of Pediatrics, Duke University School of Medicine, Durham, NC
| | - Adam Goode
- Doctor of Physical Therapy Division, Duke University School of Medicine, Durham, NC
| | - Victor Hasselblad
- Department of Biostatistics & Bioinformatics, Duke University School of Medicine, Durham, NC
| | | | - Gillian D Sanders
- Department of Medicine, Duke University School of Medicine, Durham, NC; Duke Evidence-based Practice Center, Duke Clinical Research Institute, Durham, NC
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Novel antitussive strategies. Drug Discov Today 2012; 18:380-8. [PMID: 23159360 DOI: 10.1016/j.drudis.2012.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/17/2012] [Accepted: 11/08/2012] [Indexed: 01/25/2023]
Abstract
Acute and chronic cough represent one of the most common symptoms of medical importance but effective pharmacotherapy is, to all intents and purposes, absent. Numerous initiatives targeting the recently discovered tussive pathways are in progress. Here, we review the current antitussive armamentarium and provide an update on the novel strategies and compounds in development.
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Dicpinigaitis PV. Cough: an unmet clinical need. Br J Pharmacol 2011; 163:116-24. [PMID: 21198555 PMCID: PMC3085873 DOI: 10.1111/j.1476-5381.2010.01198.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/20/2010] [Accepted: 11/23/2010] [Indexed: 12/13/2022] Open
Abstract
Cough is among the most common complaints for which patients worldwide seek medical attention. Thus, the evaluation and treatment of cough result in tremendous financial expenditure and consumption of health care resources. Yet, despite the clinical significance of cough, research efforts aimed at improving diagnostic capabilities and developing more effective therapeutic agents have been, to date, disappointing in their limited scope and outcomes. Acute cough due to the common cold represents the most common type of cough. Currently, available medications for the symptomatic management of acute cough are inadequate due to lack of proven efficacy and/or their association with undesirable or intolerable side effects at anti-tussive doses. Subacute cough, often representing a prolonged post-viral response, is typically refractory to standard anti-tussive therapy. Few clinical trials have evaluated therapeutic options for subacute cough. Diagnostic challenges facing the clinician in the management of chronic cough include the determination of whether symptoms of upper airway cough syndrome (formerly, postnasal drip syndrome) or gastro-oesophageal reflux disease are indeed the underlying cause of cough. Chronic, refractory unexplained (formerly, idiopathic) cough must be distinguished from cough that has not been fully evaluated and treated according to current guideline recommendations. Eagerly awaited are new safe and effective anti-tussive agents for use when cough suppression is desired, regardless of underlying aetiology of cough, as well as practical, validated ambulatory cough counters to aid clinical assessment and future research in the field of cough.
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Affiliation(s)
- Peter V Dicpinigaitis
- Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA.
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Abstract
This review is an update of recent advances in our understanding of cough suppressants and impairment of cough. Low-dose oral morphine has recently been shown to significantly suppress chronic cough, but the side effect profile of this opioid may limit its widespread utility. Several studies have demonstrated a dissociation between the efficacy of antitussives in some metrics of pathologic cough and their effects on cough sensitivity to inhaled irritants. The relevance of widely used inhaled irritants in understanding pathologic cough and its response to antitussives is questionable. A recent advance in the field is the identification and measurement of an index of sensation related to cough: the urge to cough. This measure highlights the potential involvement of suprapontine regions of the brain in the genesis and potential suppression of cough in the awake human. There are no new studies showing that mucolytic agents are of value as monotherapies for chronic cough. However, some of these drugs, presumably because of their antioxidant activity, may be of use as adjunct therapies or in selected patient populations. The term dystussia (impairment of cough) has been coined recently and represents a common and life-threatening problem in patients with neurologic disease. Dystussia is strongly associated with severe dysphagia and the occurrence of both indicates that the patient has a high risk for aspiration. No pharmacologic treatments ae available for dystussia, but scientists and clinicians with experience in studying chronic cough are well qualified to develop methodologies to address the problem of impaired cough.
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Affiliation(s)
- Donald C Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0144, USA.
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Abstract
Many common treatments for rhinitis symptoms are inadequate or ineffective. This may be in part because the drug does not address the pathologically altered mechanism of the rhinopathy. Objective measures may not detect treatment effects, or the treatment end points may be only subjective in nature. In many cases, these issues have not arisen because of potent placebo effects. Understanding the psychological, pharmacologic, and physiologic components of placebos is important for separating true treatment effects from those of the excipients in the vehicle. Separating the wasteful and potentially harmful effects of those excipients from the harmless and often partially beneficial effects on temporary symptom control is an important issue in clinical pharmacology that can aid in effective clinical trial design, use of objective and subjective test measures, and development of drugs to treat rhinitis.
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Loke YK, Somogyi A, Lewis LD, Schachter M, Cohen AF, Ritter JM. Looking back: editors' pick of 2008. Br J Clin Pharmacol 2009; 67:1-4. [PMID: 19133056 PMCID: PMC2668078 DOI: 10.1111/j.1365-2125.2008.03354.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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