{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T01:36:07Z","timestamp":1787016967735,"version":"build-2736575974"},"reference-count":39,"publisher":"BMJ","issue":"7297","license":[{"start":{"date-parts":[[2001,5,26]],"date-time":"2001-05-26T00:00:00Z","timestamp":990835200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/www.bmj.com\/company\/legal-information\/terms-conditions\/legal-information\/tdm-licencepolicy"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["BMJ"],"accepted":{"date-parts":[[2001,2,28]]},"published-print":{"date-parts":[[2001,5,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    <jats:bold>Objective:<\/jats:bold>\n                    To assess the effects of oral mucolytics in adults with stable chronic bronchitis and chronic obstructive pulmonary disease.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:bold>Design:<\/jats:bold>\n                    Systematic review of randomised controlled trials that compared at least two months of regular oral mucolytic drugs with placebo.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:bold>Studies:<\/jats:bold>\n                    Twenty three randomised controlled trials in outpatients in Europe and United States.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:bold>Main outcome measures:<\/jats:bold>\n                    Exacerbations, days of illness, lung function, adverse events.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:bold>Results:<\/jats:bold>\n                    Compared with placebo, the number of exacerbations was significantly reduced in subjects taking oral mucolytics (weighted mean difference \u22120.07 per month, 95% confidence interval \u22120.08 to \u22120.05, P&lt;0.0001). Based on the annualised rate of exacerbations in the control subjects of 2.7 a year, this is a 29% reduction. The number needed to treat for one subject to have no exacerbation in the study period would be 6. Days of illness also fell (weighted mean difference \u22120.56, \u22120.77 to \u22120.35, P&lt;0.0001). The number of subjects who had no exacerbations in the study period was greater in the mucolytic group (odds ratio 2.22, 95% confidence interval 1.93 to 2.54, P&lt;0.0001). There was no difference in lung function or in adverse events reported between treatments.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:bold>Conclusions:<\/jats:bold>\n                    In chronic bronchitis and chronic obstructive pulmonary disease, treatment with mucolytics is associated with a reduction in acute exacerbations and days of illness. As these drugs have to be taken long term, they could be most useful in patients who have repeated, prolonged, or severe exacerbations of chronic obstructive pulmonary disease.\n                  <\/jats:p>\n                  <jats:p>\n                    <jats:boxed-text position=\"float\">\n                      <jats:sec>\n                        <jats:title>What is already known on this topic<\/jats:title>\n                        <jats:p>Mucolytic drugs have properties that may be beneficial in chronic obstructive pulmonary disease<\/jats:p>\n                        <jats:p>These drugs are not prescribed in the United Kingdom and Australasia, although they are widely used in many other countries<\/jats:p>\n                        <jats:p>Drugs that reduce exacerbations may reduce the morbidity and healthcare costs associated with progressively severe disease<\/jats:p>\n                      <\/jats:sec>\n                      <jats:sec>\n                        <jats:title>What this study adds<\/jats:title>\n                        <jats:p>Regular use of mucolytic drugs for at least two months significantly reduces exacerbations and days of illness compared with placebo in patients with chronic bronchitis and chronic obstructive pulmonary disease<\/jats:p>\n                        <jats:p>Exacerbations that do occur may not be as severe, and the benefit may be greater in those with more severe disease<\/jats:p>\n                        <jats:p>Reductions are modest and treatment may not be cost effective<\/jats:p>\n                      <\/jats:sec>\n                    <\/jats:boxed-text>\n                  <\/jats:p>","DOI":"10.1136\/bmj.322.7297.1271","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T06:43:06Z","timestamp":1027752186000},"page":"1271","source":"Crossref","is-referenced-by-count":175,"title":["Oral mucolytic drugs for exacerbations of chronic obstructive pulmonary disease: systematic review"],"prefix":"10.1136","volume":"322","author":[{"given":"Phillippa J","family":"Poole","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter N","family":"Black","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2001,5,26]]},"reference":[{"key":"2025122109302693000_322.7297.1271.1","unstructured":"Redline S .Epidemiology of COPD.In: Cherniack N ed.Chronic obstructive pulmonary disease. 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Oxford: Oxford University Press,1976."},{"key":"2025122109302693000_322.7297.1271.3","doi-asserted-by":"crossref","first-page":"1418","DOI":"10.1164\/ajrccm.157.5.9709032","article-title":"Effect of exacerbation on quality of life in patients with chronic obstructive pulmonary disease","volume":"157","author":"Seemungal","year":"1998","journal-title":"Am J Respir Crit Care Med"},{"key":"2025122109302693000_322.7297.1271.4","doi-asserted-by":"crossref","first-page":"S9","DOI":"10.1164\/ajrccm\/140.3_Pt_2.S9","article-title":"Trends in COPD morbidity and mortality in the United States","volume":"140","author":"Feinleib","year":"1989","journal-title":"Am Rev Respir Dis"},{"key":"2025122109302693000_322.7297.1271.5","first-page":"714","article-title":"Mucoactive drugs in the management of chronic obstructive pulmonary disease","volume":"53","author":"Del Donno","year":"1998","journal-title":"Monaldi Arch Chest Dis"},{"key":"2025122109302693000_322.7297.1271.6","doi-asserted-by":"publisher","DOI":"10.1136\/thx.52.6.565"},{"key":"2025122109302693000_322.7297.1271.7","unstructured":"British Medical Association, Royal Pharmaceutical Society of Great Britain .British National Formulary. 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