Effect of twelve-months therapy with oral ambroxol in preventing exacerbations in patients with COPD. Double-blind, randomized, multicenter, placebo-controlled study (the AMETHIST Trial)

Efficacy and safety of mucolytics in patients with stable chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

The efficacy and safety of mucolytics in patients with chronic obstructive pulmonary disease (COPD) and chronic bronchitis or exacerbations of COPD have been reported. We conducted a systematic review and meta-analysis of mucolytics in patients with stable COPD.

METHODS

Reports from randomized controlled trials to evaluate the efficacy and safety of mucolytics, including ambroxol, bromhexine, carbocisteine, erdosteine, fudosteine, l-methylcysteine, and N-acetylcysteine used in patients with stable COPD were searched for in PubMed, Scopus, Embase, Web of Science, the Cochrane Library, and the Igaku Cyuo Zasshi database.

RESULTS

Twenty-three reports with ambroxol, carbocisteine, erdosteine, l-methylcysteine, or N-acetylcysteine were included in the review. Mucolytics significantly reduced the rates of exacerbation and hospitalization, shortened the duration of antibiotic use and exacerbations, prolonged the time to first exacerbation, and had a tendency to reduce the occurrence of two or more exacerbations in patients with stable COPD compared to placebo. Mucolytics did not improve mortality, number of lost workdays, scores on St. George's respiratory questionnaire, forced expiratory volume in 1 s, or forced vital capacity. The safety profile of mucolytics was comparable to that of placebo.

CONCLUSIONS

Mucolytics reduce exacerbations and hospitalizations in patients with stable COPD and have a safety profile comparable to that of placebo.

Evaluation of safety and efficacy of inhaled ambroxol in hospitalized adult patients with mucopurulent sputum and expectoration difficulty

Background

Ambroxol is a widely used mucoactive drug in sputum clearance of respiratory diseases taken orally and by injection. However, there is a paucity of evidence for inhaled ambroxol in sputum clearance.

Methods

This study performed a multicenter, randomized, double-blind, placebo-controlled, phase 3 trial at 19 centers in China. Hospitalized adult patients with mucopurulent sputum and expectoration difficulty were recruited. Patients were randomized by 1:1 to receive inhalation of either ambroxol hydrochloride solution 3 mL (22.5 mg) + 0.9% sodium chloride 3 mL or 0.9% sodium chloride 6 mL twice daily for 5 days, with an interval of more than 6 h. The primary efficacy endpoint was the absolute change in the sputum property score after treatment compared to the baseline in the intention-to-treat population.

Results

Between 10 April 2018 and 23 November 2020, 316 patients were recruited and assessed for eligibility, of whom 138 who received inhaled ambroxol and 134 who received a placebo were included. Patients who received inhaled ambroxol had a significantly greater decrease in the sputum property score compared with patients who received inhalation of placebo (difference: -0.29; 95% CI: -0.53 to -0.05; p = 0.0215). Compared with the placebo, inhaled ambroxol also significantly reduced more expectoration volume in 24 h (difference: -0.18; 95% CI: -0.34 to -0.03; p  = 0.0166). There was no significant difference in the proportion of adverse events between the two groups, and no deaths were reported.

Discussion

In hospitalized adult patients with mucopurulent sputum and expectoration difficulty, inhaled ambroxol was safe and effective for sputum clearance compared with a placebo.

Clinical trial registration

[https://www.chictr.org.cn/showproj.html?proj=184677], Chinese Clinical Trial Registry [ChiCTR2200066348].

COPD Maintenance Pharmacotherapy

Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death worldwide and will likely be the third most common cause by the end of 2020. It is felt to be caused by repetitive noxious stimuli to the lung, most commonly from smoking, with persistent symptoms of cough, wheeze, and shortness of breath. Most patients will have these baseline symptoms, with periodic flare-ups known as exacerbations. This article focuses on pharmacological therapy in a stable COPD patient. Pharmacological treatment of a stable COPD patient focuses on minimizing symptoms, improving exercise tolerance, and preventing exacerbations. Nonpharmacological management of stable COPD, smoking cessation, and treatment of exacerbations are covered in other sections.

Pharmacokinetics of Ambroxol Sustained Release (Mucosolvan® Retard) Compared with Other Formulations in Healthy Volunteers

INTRODUCTION

Ambroxol is used in the treatment of acute and chronic respiratory conditions characterized by abnormal mucus secretion and impaired mucus transport and is available in a variety of formulations. This study aimed to compare the steady-state (SS) pharmacokinetic characteristics of extended-release (ER) 75-mg retard capsules with two immediate-release (IR) formulations (60-mg effervescent tablets and 30-mg tablets) over a 24-h period.

METHODS

An open-label, randomized, three-period, six-sequence crossover study was conducted in healthy volunteers aged 18-45 years who had a normal body mass index. The test (ER 75-mg retard capsule once daily) and reference treatments (half of IR 60-mg effervescent tablet twice daily or 30-mg IR tablet twice daily) were administered on days 1-5 of each treatment period. Meals were standardized and concomitant therapy was prohibited. Blood samples for pharmacokinetic assessment were collected on day 5 (SS) of each treatment period. The co-primary endpoints were exposure (AUCSS 0-24) and maximum plasma level (Cmax SS).

RESULTS

Twenty-four participants received ambroxol (male n = 13, 54.2%; mean ± standard deviation [SD] age 25.0 ± 6.4 years) and 23 completed the study. ER retard capsules provided similar AUCSS 0-24 compared to IR tablets (geometric means ratio [GMR] 110.7%; 90% confidence interval [CI] 99.8%, 122.7%) and effervescent tablets (GMR 106.9%; 90% CI 100.3%, 114.0%). ER retard capsules provided similar Cmax SS compared to IR tablets (GMR 84.7%, 90% CI 77.0%, 93.3%), and lower Cmax SS compared to effervescent tablets (GMR 80.9%, 90% CI 73.9%, 88.6%). Time to Cmax SS (tmax SS) was longer with ER retard capsules (6.0 h) than with IR tablets (2.0 h) or effervescent tablets (1.0 h).

CONCLUSIONS

ER ambroxol 75-mg retard capsules given once daily showed a similar pharmacokinetic profile to IR ambroxol formulations and therefore can be used instead of these in the treatment of respiratory conditions. CLINICALTRIALS.

GOV IDENTIFIER

NCT02036775.

Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume or purulence of sputum, or both. Personal and healthcare costs associated with exacerbations indicate that therapies that reduce the occurrence of exacerbations are likely to be useful. Mucolytics are oral medicines that are believed to increase expectoration of sputum by reducing its viscosity, thus making it easier to cough it up. Improved expectoration of sputum may lead to a reduction in exacerbations of COPD.

OBJECTIVES

Primary objective• To determine whether treatment with mucolytics reduces exacerbations and/or days of disability in patients with chronic bronchitis or COPDSecondary objectives• To assess whether mucolytics lead to improvement in lung function or quality of life• To determine frequency of adverse effects associated with use of mucolytics SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register and reference lists of articles on 12 separate occasions, most recently on 23 April 2019.

SELECTION CRITERIA

We included randomised studies that compared oral mucolytic therapy versus placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

DATA COLLECTION AND ANALYSIS

This review analysed summary data only, most derived from published studies. For earlier versions, one review author extracted data, which were rechecked in subsequent updates. In later versions, review authors double-checked extracted data and then entered data into RevMan 5.3 for analysis.

MAIN RESULTS

We added four studies for the 2019 update. The review now includes 38 trials, recruiting a total of 10,377 participants. Studies lasted between two months and three years and investigated a range of mucolytics, including N-acetylcysteine, carbocysteine, erdosteine, and ambroxol, given at least once daily. Many studies did not clearly describe allocation concealment, and we had concerns about blinding and high levels of attrition in some studies. The primary outcomes were exacerbations and number of days of disability.Results of 28 studies including 6723 participants show that receiving mucolytics may be more likely to be exacerbation-free during the study period compared to those given placebo (Peto odds ratio (OR) 1.73, 95% confidence interval (CI) 1.56 to 1.91; moderate-certainty evidence). However, more recent studies show less benefit of treatment than was reported in earlier studies in this review. The overall number needed to treat with mucolytics for an average of nine months to keep an additional participant free from exacerbations was eight (NNTB 8, 95% CI 7 to 10). High heterogeneity was noted for this outcome (I² = 62%), so results need to be interpreted with caution. The type or dose of mucolytic did not seem to alter the effect size, nor did the severity of COPD, including exacerbation history. Longer studies showed smaller effects of mucolytics than were reported in shorter studies.Mucolytic use was associated with a reduction of 0.43 days of disability per participant per month compared with use of placebo (95% CI -0.56 to -0.30; studies = 9; I² = 61%; moderate-certainty evidence). With mucolytics, the number of people with one or more hospitalisations was reduced, but study results were not consistent (Peto OR 0.68, 95% CI 0.52 to 0.89; participants = 1788; studies = 4; I² = 58%; moderate-certainty evidence). Investigators reported improved quality of life with mucolytics (mean difference (MD) -1.37, 95% CI -2.85 to 0.11; participants = 2721; studies = 7; I² = 64%; moderate-certainty evidence). However, the mean difference did not reach the minimal clinically important difference of -4 units, and the confidence interval includes no difference. Mucolytic treatment was associated with a possible reduction in adverse events (OR 0.84, 95% CI 0.74 to 0.94; participants = 7264; studies = 24; I² = 46%; moderate-certainty evidence), but the pooled effect includes no difference if a random-effects model is used. Several studies that could not be included in the meta-analysis reported high numbers of adverse events, up to a mean of five events per person during follow-up. There was no clear difference between mucolytics and placebo for mortality, but the confidence interval is too wide to confirm that treatment has no effect on mortality (Peto OR 0.98, 95% CI 0.51 to 1.87; participants = 3527; studies = 11; I² = 0%; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, we are moderately confident that treatment with mucolytics leads to a small reduction in the likelihood of having an acute exacerbation, in days of disability per month and possibly hospitalisations, but is not associated with an increase in adverse events. There appears to be limited impact on lung function or health-related quality of life. Results are too imprecise to be certain whether or not there is an effect on mortality. Our confidence in the results is reduced by high levels of heterogeneity in many of the outcomes and the fact that effects on exacerbations shown in early trials were larger than those reported by more recent studies. This may be a result of greater risk of selection or publication bias in earlier trials, thus benefits of treatment may not be as great as was suggested by previous evidence.

Safety of ambroxol in the treatment of airway diseases in adult patients

INTRODUCTION

Ambroxol is a widely used secretolytic and mucoactive over-the-counter agent primarily used to treat respiratory diseases associated with viscid mucus. Following post-marketing reports of hypersensitivity reactions and severe cutaneous adverse reactions (SCARs) possibly linked to ambroxol, the European Union's Pharmacovigilance Risk Assessment Committee (PRAC) initiated in April 2014 a review of the safety of ambroxol in all its registered indications, which was finalized in 2016. Areas covered: Here, we evaluate the clinical safety of ambroxol and provide an expert opinion on the benefit-risk balance of ambroxol in the treatment of adult patients with bronchopulmonary diseases. The evidence for this review is derived from clinical trials of ambroxol that were provided to the PRAC by the marketing authorization holders of ambroxol-containing medicines. Expert opinion: Clinical experience accumulated from randomized clinical trials and observational studies suggests that ambroxol is a safe and well-tolerated treatment of bronchopulmonary diseases, with a well-balanced and favorable benefit-risk profile. All reported adverse events were mild and self-limiting, and the risk of SCARs with ambroxol is low. Further investigations could address the safety and efficacy of ambroxol in pediatric lung diseases and in additional therapeutic indications, such as biofilm-dependent airway disease and lysosomal storage disorders.

Management of airway mucus hypersecretion in chronic airway inflammatory disease: Chinese expert consensus (English edition)

Airway mucus hypersecretion is one of the most important characteristics of chronic airway inflammatory diseases. Evaluating and managing airway mucus hypersecretion is of great importance for patients with chronic airway inflammatory diseases. This consensus statement describes the pathogenesis, clinical features, and the management of airway mucus hypersecretion in patients with chronic airway inflammatory diseases in the People's Republic of China. The statement has been written particularly for respiratory researchers, pulmonary physicians, and patients.

Ambroxol for the treatment of fibromyalgia: science or fiction?

Fibromyalgia appears to present in subgroups with regard to biological pain induction, with primarily inflammatory, neuropathic/neurodegenerative, sympathetic, oxidative, nitrosative, or muscular factors and/or central sensitization. Recent research has also discussed glial activation or interrupted dopaminergic neurotransmission, as well as increased skin mast cells and mitochondrial dysfunction. Therapy is difficult, and the treatment options used so far mostly just have the potential to address only one of these aspects. As ambroxol addresses all of them in a single substance and furthermore also reduces visceral hypersensitivity, in fibromyalgia existing as irritable bowel syndrome or chronic bladder pain, it should be systematically investigated for this purpose. Encouraged by first clinical observations of two working groups using topical or oral ambroxol for fibromyalgia treatments, the present paper outlines the scientific argument for this approach by looking at each of the aforementioned aspects of this complex disease and summarizes putative modes of action of ambroxol. Nevertheless, at this point the evidence basis for ambroxol is not strong enough for clinical recommendation.

[More than expectorant: new scientific data on ambroxol in the context of the treatment of bronchopulmonary diseases]

BACKGROUND

Ambroxol has been established for decades in the treatment of acute and chronic respiratory diseases. In 2015, the European Medicines Agency reassessed the clinical benefit-risk ratio of the drug.

OBJECTIVE

What new scientific data on ambroxol, which are relevant to the treatment of bronchopulmonary diseases, are available?

METHOD

The review is based on a systematic literature research in medline with the search term "ambroxol" during the publication period 2006-2015. Non-relevant publications were excluded manually.

RESULTS AND CONCLUSIONS

Ambroxol is still intensively researched. The traditional indication as an expectorant is confirmed. But there is also an ever better understanding of the various mechanisms of action as well as the ever more exact modeling of the structures under investigation. New fields of application are conceivable, e. g. in patients with severe pulmonary disease who undergo surgery or who are in intensive care, as an adjuvant in anti-infective therapies, especially in infections with biofilm-producing pathogens, or in rare diseases such as lysosomal storage diseases. However, final evidence of the clinical relevance in these fields of application is still missing.

Mucoactive and antioxidant medicines for COPD: consensus of a group of Chinese pulmonary physicians

Airway mucus hypersecretion is a frequent symptom associated with acute and chronic airway disease. Inhibition of mucus production or promotion of mucolysis not only relieved symptoms but also improved disease outcomes. There are numerous available mucoactive medicines for prescription, and how to select them properly for different diseases is important for clinical practice. So far, there is no one consensus or guideline reported. A group of Chinese pulmonary physicians worked together to complete this consensus based on literature review, summarized mechanism and usage of each classical mucoactive medicine. In general, antioxidant mucoactive medicines play an important role in chronic airway disease, including but not limited to airway mucus clearance, reduced acute exacerbation and improved pulmonary function.

Immunomodulatory Effects of Ambroxol on Airway Hyperresponsiveness and Inflammation

Ambroxol is used in COPD and asthma to increase mucociliary clearance and regulate surfactant levels, perhaps through anti-oxidant and anti-inflammatory activities. To determine the role and effect of ambroxol in an experimental model of asthma, BALB/c mice were sensitized to ovalbumin (OVA) followed by 3 days of challenge. Airway hyperresponsiveness (AHR), lung cell composition and histology, and cytokine and protein carbonyl levels in bronchoalveolar lavage (BAL) fluid were determined. Ambroxol was administered either before the first OVA challenge or was begun after the last allergen challenge. Cytokine production levels from lung mononuclear cells (Lung MNCs) or alveolar macrophages (AM) were also determined. Administration of ambroxol prior to challenge suppressed AHR, airway eosinophilia, goblet cell metaplasia, and reduced inflammation in subepithelial regions. When given after challenge, AHR was suppressed but without effects on eosinophil numbers. Levels of IL-5 and IL-13 in BAL fluid were decreased when the drug was given prior to challenge; when given after challenge, increased levels of IL-10 and IL-12 were detected. Decreased levels of protein carbonyls were detected in BAL fluid following ambroxol treatment after challenge. In vitro, ambroxol increased levels of IL-10, IFN-γ, and IL-12 from Lung MNCs and AM, whereas IL-4, IL-5, and IL-13 production was not altered. Taken together, ambroxol was effective in preventing AHR and airway inflammation through upregulation of Th1 cytokines and protection from oxidative stress in the airways.

Pharmacological effects of lysozyme on COPD and bronchial asthma with sputum: A randomized, placebo-controlled, small cohort, cross-over study

BACKGROUND

Mucolytic agents are often used in Japan to ease excessive mucus production in patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma (BA); the treatment ameliorates dyspnea and improves quality of life (QOL).

AIM

Efficacy and safety of lysozyme hydrochloride (LYS), an oral mucolytic enzyme preparation, for patients with COPD or BA were investigated.

PATIENTS AND METHODS

This study was a placebo-controlled, double-blind, randomized, cross-over design. Twenty-four patients with COPD and twenty-four patients with BA were enrolled. LYS or placebo was administered for 28 days in each treatment period, with a 28-day washout between the first and second treatment periods. The results of spirometry, impulse oscillometry system (IOS) examination, fractional exhaled nitric oxide (FeNO) measurement, as well as the changes in the subjective symptoms, were evaluated after the treatment period.

RESULTS

On spirometry, airway function (FEV1) improved in patients with COPD after administration of LYS (LYS vs placebo: 0.08 L vs 0.029 L, p = 0.030). Similar trends were also found in %FEV1 in COPD patients. On IOS examination, resistance of the respiratory system at 5 Hz levels was significantly improved only in patients with COPD (LYS vs placebo: -0.455 cm H2O/L/s vs 0.095 cmH2O/L/s, p = 0.012). Similar trends were found in terms of the resistance of the respiratory system at 20 Hz, and of the reactance area. In the COPD assessment test, subjective symptoms also significantly improved in patients with COPD during the LYS treatment period (improvement rates-LYS vs. placebo: 69.6% vs. 39.1%; p = 0.022). A similar effect of LYS was not seen in BA patients.

CONCLUSION

LYS, a mucolytic agent, has capability to improve the function of peripheral airways in patients with COPD, which leads to improvements of the patients' symptoms and QOL.

Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume or purulence of sputum, or both. Personal and healthcare costs associated with exacerbations indicate that any therapy that reduces the occurrence of exacerbations is useful. A marked difference among countries in terms of prescribing of mucolytics reflects variation in perceptions of their effectiveness.

OBJECTIVES

Primary objective• To determine whether treatment with mucolytics reduces frequency of exacerbations and/or days of disability in patients with chronic bronchitis or chronic obstructive pulmonary disease. Secondary objectives• To assess whether mucolytics lead to improvement in lung function or quality of life.• To determine frequency of adverse effects associated with use of mucolytics.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register and reference lists of articles on 10 separate occasions, most recently in July 2014.

SELECTION CRITERIA

We included randomised studies that compared oral mucolytic therapy versus placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

DATA COLLECTION AND ANALYSIS

This review analysed summary data only, most derived from published studies. For earlier versions, one review author extracted data, which were rechecked in subsequent updates. In later versions, review authors double-checked extracted data and then entered data into RevMan for analysis.

MAIN RESULTS

We added four studies for the 2014 update. The review now includes 34 trials, recruiting a total of 9367 participants. Many studies did not clearly describe allocation concealment; hence selection bias may have inflated the results, which reduces our confidence in the findings.Results of 26 studies with 6233 participants show that the likelihood that a patient could be exacerbation-free during the study period was greater among mucolytic groups (Peto odds ratio (OR) 1.75, 95% confidence interval (CI) 1.57 to 1.94). However, more recent studies show less benefit of treatment than was reported in earlier studies in this review. The overall number needed to treat with mucolytics for an additional beneficial outcome for an average of 10 months - to keep an additional participant free from exacerbations - was eight (NNTB 8, 95% CI 7 to 10). Use of mucolytics was associated with a reduction of 0.03 exacerbations per participant per month (mean difference (MD) -0.03, 95% CI -0.04 to -0.03; participants = 7164; studies = 28; I(2) = 85%) compared with placebo, that is, about 0.36 per year, or one exacerbation every three years. Very high heterogeneity was noted for this outcome, so results need to be interpreted with caution. The type or dose of mucolytic did not seem to alter the effect size, nor did the severity of COPD, including exacerbation history. Longer studies showed smaller effects of mucolytics than were reported in shorter studies.Mucolytic use was associated with a reduction of 0.43 days of disability per participant per month compared with placebo (95% CI -0.56 to -0.30; studies = 13; I(2) = 61%). With mucolytics, the number of people with one or more hospitalisations was reduced, but study results were not consistent (Peto OR 0.68, 95% CI 0.52 to 0.89; participants = 1788; studies = 4; I(2) = 58%). Investigators reported improved quality of life with mucolytics (MD -2.64, 95% CI -5.21 to -0.08; participants = 2231; studies = 5; I(2) = 51%). Although this mean difference did not reach the minimal clinically important difference of -4 units, we cannot assess the population impact, as we do not have the data needed to carry out a responder analysis. Mucolytic treatment was not associated with any significant increase in the total number of adverse effects, including mortality (Peto OR 1.03, 95% CI 0.52 to 2.03; participants = 2931; studies = 8; I(2) = 0%), but the confidence interval is too wide to confirm that the treatment has no effect on mortality.

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, we are moderately confident that treatment with mucolytics may produce a small reduction in acute exacerbations and a small effect on overall quality of life. Our confidence in the results is reduced by the fact that effects on exacerbations shown in early trials were larger than those reported by more recent studies, possibly because the earlier smaller trials were at greater risk of selection or publication bias, thus benefits of treatment may not be as great as was suggested by previous evidence.

Effect of Ambroxol and Beclomethasone on Lipopolysaccharide-Induced Nitrosative Stress in Bronchial Epithelial Cells

BACKGROUND

Nitrosative stress is involved in different airway diseases. Lipopolysaccharide (LPS) induces neutrophil-related cytokine release and nitrosative stress in human bronchial epithelial (BEAS-2B) cells alone or with human polymorphonuclear neutrophils (PMNs). Ambroxol protects against oxidative stress, and beclomethasone dipropionate is an anti-inflammatory drug.

OBJECTIVES

We evaluated the ability of ambroxol and/or beclomethasone dipropionate to inhibit LPS-induced expression/release of RANTES, IL-8, inducible NO synthase (iNOS), myeloperoxidase (MPO) and 3-nitrotyrosine (3-NT: nitrosative stress biomarker) in BEAS-2B ± PMNs stimulated with LPS (1 μg/ml).

METHODS

The effect of ambroxol and/or beclomethasone dipropionate on IL-8, RANTES and iNOS levels was assessed by Western blot analysis; IL-8, MPO and 3-NT levels were measured by ELISA. Cell viability was assessed by the trypan blue exclusion test.

RESULTS

In BEAS-2B alone, LPS (at 12 h) increased RANTES/iNOS expression and IL-8 levels (p < 0.001). Ambroxol suppressed LPS-induced RANTES expression and IL-8 release (p < 0.001), whilst inhibiting iNOS expression (p < 0.05). Beclomethasone dipropionate had no effect on RANTES but halved iNOS expression and IL-8 release. Coculture of BEAS-2B with PMNs stimulated IL-8, MPO and 3-NT production (p < 0.001), potentiated by LPS (p < 0.001). Ambroxol and beclomethasone dipropionate inhibited LPS-stimulated IL-8, MPO and 3-NT release (p < 0.05). Ambroxol/beclomethasone dipropionate combination potentiated the inhibition of IL-8 and 3-NT production in BEAS-2B with PMNs (p < 0.05 and p < 0.01, respectively). Ambroxol and/or beclomethasone dipropionate inhibited nitrosative stress and the release of neutrophilic inflammatory products in vitro.

CONCLUSION

The additive effect of ambroxol and beclomethasone dipropionate on IL-8 and 3-NT inhibition suggests new therapeutic options in the treatment of neutrophil-related respiratory diseases such as chronic obstructive pulmonary disease and respiratory infections.

Biofilm-dependent airway infections: a role for ambroxol?

Biofilms are a key factor in the development of both acute and chronic airway infections. Their relevance is well established in ventilator associated pneumonia, one of the most severe complications in critically ill patients, and in cystic fibrosis, the most common lethal genetic disease in Caucasians. Accumulating evidence suggests that biofilms could have also a role in chronic obstructive pulmonary disease and their involvement in bronchiectasis has been proposed as well. When they grow in biofilms, microorganisms become multidrug-resistant. Therefore the treatment of biofilm-dependent airway infections is problematic. Indeed, it still largely based on measures aiming to prevent the formation of biofilms or remove them once that they are formed. Here we review recent evidence suggesting that the mucokinetic drug ambroxol has specific anti-biofilm properties. We also discuss how additional pharmacological properties of this drug could be beneficial in biofilm-dependent airway infections. Specifically, we review the evidence showing that: 1-ambroxol exerts anti-inflammatory effects by inhibiting at multiple levels the activity of neutrophils, and 2-it improves mucociliary clearance by interfering with the activity of airway epithelium ion channels and transporters including sodium/bicarbonate and sodium/potassium/chloride cotransporters, cystic fibrosis transmembrane conductance regulator and aquaporins. As a whole, the data that we review here suggest that ambroxol could be helpful in biofilm-dependent airway infections. However, considering the limited clinical evidence available up to date, further clinical studies are required to support the use of ambroxol in these diseases.

A thioredoxin reductase and/or thioredoxin system-based mechanism for antioxidant effects of ambroxol

Long-term treatment with ambroxol (ABX), a bronchial expectorant, was found to prevent acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The underlying mechanism remains unclear. To address this, we have investigated the effect of ABX on critical antioxidant proteins thioredoxin (Trx) and thioredoxin reductase (TrxR) that are decreased in patients with AECOPD. Trx, TrxR and NADP(H) form Trx system, which is involved in regulating numerous oxidative stress-related events. In human bronchial epithelial cells, treatment with ABX from 0 to 200 μM gradually increased mRNA and protein levels of TrxR/Trx. At these ABX concentrations, TrxR activity was elevated progressively, whereas Trx activity exhibited a dose-dependent biphasic response, increasing at 50 and 75 μM, but decreasing at ABX over 150 μM. Pre-treatment with 75 μM ABX enhanced the capacity of the cells to eliminate reactive oxygen species, which was largely prevented by knockdown of cytosolic Trx (hTrx1). In a purified system, ABX shortened the initial lag phase during the reduction of insulin disulfide by Trx system. Pre-treatment of NADPH-reduced TrxR with ABX caused a dose- and time-dependent increase in thiolate/selenolate species, i.e. the catalytically active form of TrxR. Kinetic analysis demonstrated that the reduction of H2O2 by TrxR or Trx system were enhanced by 100 or 200 μM ABX. When hTrx1 was mixed with ABX in a molar ratio of 1:1 to 1:100 (which could occur in human plasma), changes in intrinsic Trp fluorescence occurred, and the response of reduced hTrx1 was especially remarkable. These data reveal an ABX-sensing mechanism of TrxR/Trx. We therefore conclude that the antioxidant actions of ABX at physiological concentrations are, at least partially, mediated by TrxR and/or Trx system.

Ambroxol inhibits rhinovirus infection in primary cultures of human tracheal epithelial cells

The mucolytic drug ambroxol hydrochloride reduces the production of pro-inflammatory cytokines and the frequency of exacerbation in patients with chronic obstructive pulmonary disease (COPD). However, the inhibitory effects of ambroxol on rhinovirus infection, the major cause of COPD exacerbations, have not been studied. We examined the effects of ambroxol on type 14 rhinovirus (RV14) infection, a major RV group, in primary cultures of human tracheal epithelial cells. RV14 infection increased virus titers and cytokine content in the supernatants and RV14 RNA in the cells. Ambroxol (100 nM) reduced RV14 titers and cytokine concentrations of interleukin (IL)-1β, IL-6 and IL-8 in the supernatants and RV14 RNA in the cells after RV14 infection, in addition to reducing susceptibility to RV14 infection. Ambroxol also reduced the expression of intercellular adhesion molecule-1 (ICAM-1), the receptor for RV14, and the number of acidic endosomes from which RV14 RNA enters the cytoplasm. In addition, ambroxol reduced the activation of the transcription factor nuclear factor kappa B (NF-κB) in the nucleus. These results suggest that ambroxol inhibits RV14 infection partly by reducing ICAM-1 and acidic endosomes via the inhibition of NF-κB activation. Ambroxol may modulate airway inflammation by reducing the production of cytokines in rhinovirus infection.

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume or purulence of sputum, or both. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is useful. There is a marked difference among countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

PRIMARY OBJECTIVE

to determine if treatment with mucolytics reduces the frequency of exacerbations, days of disability, or both, in participants with chronic bronchitis or chronic obstructive pulmonary disease, or both.

SECONDARY OBJECTIVES

to determine if mucolytics lead to an improvement in lung function or quality of life and to determine the frequency of adverse effects associated with mucolytics.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register and reference lists of articles on ten separate occasions, the most recent being in July 2012.

SELECTION CRITERIA

We included randomised studies that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

DATA COLLECTION AND ANALYSIS

The review analysed summary data only, the majority from published studies. For earlier versions, one author extracted data, which was rechecked in subsequent updates. In later versions, we double-checked data extraction. We then entered data into RevMan for analysis.

MAIN RESULTS

Two further trials have been added to the review for the 2012 update. There are now 30 trials in the review, recruiting a total of 7436 participants. Allocation concealment was not clearly described in the early trials, and selection bias may have inflated the results, which reduces our confidence in the findings of these trials.The likelihood of being exacerbation-free during the study period (22 trials in 4886 participants with a mean duration of 10 months) was greater in the mucolytic group for the double-blind trials (Peto odds ratio (OR) 1.84; 95% confidence interval (CI) 1.63 to 2.07). However, the more recent trials show less benefit of treatment than the earlier trials included in this review. The overall number needed to treat with mucolytics to keep an additional participant free from exacerbations over 10 months was seven (NNTB 7; 95% CI 6 to 9). The use of mucolytics was associated with a reduction of 0.04 exacerbations per participant per month (95% CI -0.04 to -0.03) compared with placebo; that is about 0.48 per year, or one exacerbation every two years. There was very high heterogeneity in this outcome (I(2) = 87%) so results need to be interpreted with caution.The number of days of disability per month also fell (mean difference (MD) -0.48; 95% CI -0.65 to -0.30) in 12 trials on 2305 participants. There was no clinically important improvement in lung function or consistent impact on quality of life with mucolytics. Mucolytic treatment was not associated with any significant increase in adverse effects, including mortality (Peto OR 0.75; 95% CI 0.35 to 1.64) in six trials on 1821 participants.

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, treatment with a mucolytic may produce a small reduction in acute exacerbations, but may have little or no effect on the overall quality of life. The effects on exacerbations shown in early trials were larger than those found in the more recent studies. This may be because the earlier smaller trials were at higher risk of selection or publication bias, so the benefits of treatment may not be as large as suggested by the previous evidence.

Ambroxol: a multifaceted molecule with additional therapeutic potentials in respiratory disorders of childhood

INTRODUCTION

Mucoactive drugs are currently used to cleanse the respiratory tract following disturbance of the normal mucociliary clearance due to mucous hyperproduction and/or modification of its physicochemical characteristics. However, in addition to possessing the ability to perform specific actions on airway secretion, these compounds have the capability to modulate the mechanisms involved in abnormal secretions. Indeed, over the years, in the postmarketing phase, a large number of studies have been published showing interesting pharmacological activities in addition to their secretagogue activity.

AREAS COVERED

This article collates available data on ambroxol (2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine), a metabolite of bromhexine, used as a secretagogue in the treatment of childhood airway diseases. This article goes beyond the mucoactive aspects of the drug covering its multiple pharmacological properties.

EXPERT OPINION

The non-mucoactive functions exhibited by the compound may provide beneficial effects on airway structure and function in health and disease. Beyond the mucokinetic and secretagogue effects, ambroxol showed great antioxidant, anti-inflammatory, local anesthetic and surfactant synthesis stimulatory activities. Moreover, some antiviral and antibacterial activities were shown. These findings may better explain the clinical results observed in a variety of airway disorders and suggest additional therapeutic potential. Further studies are needed to better define the clinical relevance of these non-mucolytic activities.

Association between lung function and exacerbation frequency in patients with COPD

PURPOSE

To quantify the relationship between severity of chronic obstructive pulmonary disease (COPD) as expressed by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and the annual exacerbation frequency in patients with COPD.

METHODS

We performed a systematic literature review to identify randomized controlled trials and cohort studies reporting the exacerbation frequency in COPD patients receiving usual care or placebo. Annual frequencies were determined for total exacerbations defined by an increased use of health care (event-based), total exacerbations defined by an increase of symptoms, and severe exacerbations defined by a hospitalization. The association between the mean forced expiratory volume in one second (FEV(1))% predicted of study populations and the exacerbation frequencies was estimated using weighted log linear regression with random effects. The regression equations were applied to the mean FEV(1)% predicted for each GOLD stage to estimate the frequency per stage.

RESULTS

Thirty-seven relevant studies were found, with 43 reports of total exacerbation frequency (event-based, n = 19; symptom-based, n = 24) and 14 reports of frequency of severe exacerbations. Annual event-based exacerbation frequencies per GOLD stage were estimated at 0.82 (95% confidence interval 0.46-1.49) for mild, 1.17 (0.93-1.50) for moderate, 1.61 (1.51-1.74) for severe, and 2.10 (1.51-2.94) for very severe COPD. Annual symptom-based frequencies were 1.15 (95% confidence interval 0.67-2.07), 1.44 (1.14-1.87), 1.76 (1.70-1.88), and 2.09 (1.57-2.82), respectively. For severe exacerbations, annual frequencies were 0.11 (95% confidence interval 0.02-0.56), 0.16 (0.07-0.33), 0.22 (0.20-0.23), and 0.28 (0.14-0.63), respectively. Study duration or type of study (cohort versus trial) did not significantly affect the outcomes.

CONCLUSION

This study provides an estimate of the exacerbation frequency per GOLD stage, which can be used for health economic and modeling purposes.

Clinical efficacy of farcosolvin syrup (ambroxol-theophylline-guaiphenesin mixture) in the treatment of acute exacerbation of chronic bronchitis

BACKGROUND

Acute exacerbations of chronic bronchitis (AECB) are defined as recurrent attacks of worsening bronchial inflammation that are marked by an increase in the volume of daily sputum produced, a change in color of the expectorated sputum, and worsening dyspnea. Farcosolvin (Pharco Pharmaceuticals, Alexandria, Egypt) is a mixture of ambroxol (15 mg); theophylline (50 mg); and guaiphenesin (30 mg), per 5 mL syrup.

OBJECTIVE

To test the clinical efficacy of Farcosolvin in the treatment of AECB in a randomized, single-blinded, controlled study design.

PATIENTS AND METHODS

One hundred patients with AECB were randomized to either Farcosolvin or guaiphenesin treatment groups, in addition to the standard medical treatment for their cases. Baseline clinical symptomatolgy of breathlessness, cough, and sputum severity scoring were compared before and after 3 and 7 days of treatment in both groups and the differences compared between groups. Changes in perceived improvement were also compared between groups using the Clinical Global Impression of Improvement or Change Scale (CGIC).

RESULTS

There were statistically significant improvements in breathlessness and cough scores in both groups (pretreatment versus posttreatment at day 3 and at day 7; P < 0.05). There were highly statistically significant differences between groups in improvement in breathlessness and cough scores, after 3 and 7 days treatment, in favor of the Farcosolvin treatment group (P < 0.001). Out of 50 patients, 48 (96%) in the Farcosolvin-treated group rated their improvement on the CGIC scale as "much" and "very much" improved, while only 41 patients (82%) reported such a degree of improvement in the control group. The difference was statistically significant (P < 0.05).

CONCLUSION

We concluded from our study that Farcosolvin syrup might be safe and effective in improving symptoms in cases of acute exacerbation of chronic bronchitis.

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is useful. There is a marked difference between countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

OBJECTIVES

To assess the effects of oral mucolytics in adults with stable chronic bronchitis or COPD.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register and reference lists of articles on eight separate occasions, the most recent being in September 2008.

SELECTION CRITERIA

Randomised trials that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

DATA COLLECTION AND ANALYSIS

One review author extracted data. We contacted study authors and drug companies for missing information.

MAIN RESULTS

Twenty-eight trials involving 7042 participants were included. Compared with placebo, there was a significant reduction in the number of exacerbations per patient with oral mucolytics (weighted mean difference (WMD) -0.04 per month, 95% confidence interval -0.05 to -0.03). Using a weighted annualised rate of exacerbations in the control patients of 2.4 per year, this is a 21% reduction. The number of days of disability also fell (WMD -0.56, 95% confidence interval (CI) -0.77 to -0.35). One recent study has shown that the benefit may apply only to patients not already receiving inhaled corticosteroids. The number of patients who remained exacerbation-free was greater in the mucolytic group (odds ratio (OR) 1.93 (95% CI 1.71 to 2.17)). There is no strong evidence of improvement in lung function and treatment is not associated with any increase in adverse effects. Patients on mucolytics may be less likely to be hospitalised during the study period.

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, treatment with mucolytics was associated with a small reduction in acute exacerbations and a reduction in total number of days of disability. Benefit may be greater in individuals who have frequent or prolonged exacerbations, or those who are repeatedly admitted to hospital with exacerbations with COPD. Mucolytics should be considered for use, through the winter months at least, in patients with moderate or severe COPD in whom inhaled corticosteroids (ICS) are not prescribed.

The evidence for the use of oral mucolytic agents in chronic obstructive pulmonary disease (COPD)

INTRODUCTION

Oral mucolytics are now recommended in some treatment guidelines for the management of chronic obstructive pulmonary disease (COPD). This article reviews the evidence for their use and their possible benefits.

SOURCES OF DATA

The review is based upon peer reviewed publications relating to the use of mucolytics in COPD cited in PubMed.

AREAS OF AGREEMENT

Much of the published evidence is of somewhat poor quality and many studies include patients with both chronic bronchitis and COPD. Mucolytics reduce exacerbations by up to 0.8 exacerbations per year, but have little additional benefit in those on standard maximum therapy.

AREAS OF CONTROVERSY

Data that mucolytics improve symptoms, alter mucus or impact health-related quality of life in COPD patients receiving other standard therapy are unconvincing. In those on little or no other treatment, they may reduce exacerbation rate.

GROWING POINTS

The use of mucolytics to treat acute exacerbations is promising.

AREAS TIMELY FOR DEVELOPING RESEARCH

Head-to-head trials of mucolytics versus long-acting bronchodilators and/or inhaled corticosteroids are lacking. Even in patients with severe COPD who remain symptomatic despite maximal inhaled therapy the role of mucolytics remains unproven.

Ambroxol in the 21st century: pharmacological and clinical update

BACKGROUND

Belonging to the group of expectorants, ambroxol is an active substance with a long history that influences parameters considered to be the basis for the physiological production and the transport of the bronchial mucus. Therefore, ambroxol's indication is 'secretolytic therapy in acute and chronic bronchopulmonary diseases associated with abnormal mucus secretion and impaired mucus transport'.

OBJECTIVE

The aim of this review is to evaluate the pharmacological and clinical data on the mucokinetic compound ambroxol.

METHODS

The existing database that covers >40 years of pharmacological research and clinical development was analysed. Only studies with adequate study design were evaluated.

CONCLUSION

Ambroxol is shown to exert several activities: i) secretolytic activity (i.e., promotes mucus clearance, facilitates expectoration, and eases productive cough); ii) anti-inflammatory and antioxidant activity; and iii) a local anaesthetic effect through sodium channel blocking at the level of the cell membrane. The reduction on chronic obstructive pulmonary disease exacerbations is consistent and clinically relevant. The anaesthetic effect is a new pharmacological action that could be beneficial in the management of acute respiratory tract infections. The efficacy and safety of ambroxol is well established.

Role of mucolytics in the management of COPD

There is, to date, no medical therapy that modifies the decline in lung function that occurs in COPD. As the disease becomes more severe, exacerbations of COPD become increasingly common, affecting patient quality of life and increasing health care costs. Mucolytic agents, through their actions on inflammatory and oxidative pathways, have potential benefits in COPD. This paper reviews the randomized controlled trial (RCT) evidence for the effectiveness of at least 2 months of daily therapy with oral mucolytics in COPD. Based on evidence from 26 RCTs, mucolytics reduce exacerbations by up to 0.8 exacerbations per year, with a greater effect in patients with more severe COPD. This effect appears to be of a similar magnitude to the reduction in exacerbations seen with tiotropium and inhaled corticosteroids (ICS), but RCTs that compared the agents would be required to confirm this. Mucolytics do not affect the rate of lung function decline, but they do not have any significant adverse effects. Mucolytic treatment should be considered in: patients with more severe COPD who have frequent or prolonged exacerbations; those who are repeatedly admitted to hospital; or in those patients with frequent exacerbations who are unable to take tiotropium or ICS.

From Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines to current clinical practice : an overview of the pharmacological therapy of stable chronic obstructive pulmonary disorder

BACKGROUND

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines have been promulgated to improve the management of chronic obstructive pulmonary disorder (COPD).

OBJECTIVE

To evaluate the extent to which the current therapeutic approach to COPD conforms to GOLD guidelines.

METHODS

This was a multicentre observational study of elderly COPD patients enrolled for acute care in general medicine or geriatric wards in tertiary hospitals in Italy in April 2002. Our series consisted of 471 patients >64 years of age consecutively admitted for acute exacerbations of COPD to wards participating in the study. Data describing drugs used prior to exacerbation and prescribed at discharge were collected using a standardised protocol. Changes in prescription at discharge were then compared with home therapy. Demographic variables and indices of COPD severity and co-morbidity were tested as potential correlates for the main outcome measure 'variant prescription', i.e. prescription of a drug considered as a third-line treatment (e.g. methylxanthines) or not recommended (e.g. mucolytics) by GOLD guidelines. The correlation was assessed first by univariate analysis and then by logistic regression analysis.

RESULTS

At discharge, prescription of short-acting beta(2)-adrenoceptor agonists had decreased from 26.3% to 14.0%. Conversely, increases in prescription of long-actingbeta(2)-adrenoceptor agonists (from 43.1% to 68.4%), inhaled corticosteroids (50.7% to 69.6%) and anticholinergics (17.2% to 22.3%) were seen. The rate of use of methylxanthines was 49.7% before admission and 44.8% at discharge, with previous use being the main correlate of discharge prescription for this class of drugs (odds ratio [OR] = 4.35; 95% CI 2.88, 6.54). The rate of use of mucolytics was 26.3% before admission and 26.8% at discharge, with use of mucolytics prior to admission being the only correlate of discharge prescription (OR = 4.10; 95% CI 2.47, 6.82).

CONCLUSIONS

Hospitalisation resulted in increased adherence to GOLD guidelines in patients with COPD, but the rate of use of anticholinergics was distinctly low and that of methylxanthines and mucolytics surprisingly high. A carry-over effect (i.e. of therapy prescribed by general practitioners on that prescribed by hospital-based physicians) likely accounts for most of the 'variant prescriptions' seen at discharge from the acute care hospital.

Handle with care: targeting neutrophils in chronic obstructive pulmonary disease and severe asthma?

Neutrophils play an important role in the pathogenesis of airway inflammation in both chronic obstructive pulmonary disease (COPD) and severe asthma. Currently available drugs have only limited effects on neutrophilic airway inflammation, particularily in COPD. Therefore, great efforts are undertaken to address neutrophilic inflammation in chronic respiratory disorders, in particular COPD. This review summarizes the rationale for anti-neutrophilic treatment in COPD and asthma and gives a critical overview of current developments in drug therapy. Moreover, unanswered questions and limitations of clinical trial design and choice of outcome parameters for proof-of-concept studies with novel anti-neutrophilic drugs are discussed as well as potential safety issues.

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is useful. There is a marked difference between countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

OBJECTIVES

To assess the effects of oral mucolytics in adults with stable chronic bronchitis or COPD.

SEARCH STRATEGY

We have searched the Cochrane Airways Group Specialised Register and reference lists of articles on four separate occasions, the most recent being in June 2005. This is the third major update.

SELECTION CRITERIA

Randomised trials that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. Studies of people with asthma and cystic fibrosis were excluded.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data. Study authors and drug companies were contacted for missing information.

MAIN RESULTS

Twenty six trials were included (7335 participants). Compared with placebo, there was a significant reduction in the number of exacerbations per patient with oral mucolytics (weighted mean difference (WMD) -0.05 per month, 95% confidence interval -0.05, -0.04). Using the annualised rate of exacerbations in the control patients of 2.6 per year, this is a 20% reduction. The number of days of disability also fell (WMD -0.56, 95% confidence interval -0.77, -0.35). A recent study has shown that the benefit may apply only to those patients not already receiving inhaled corticosteroids. The number of patients who remained exacerbation-free was greater in the mucolytic group (OR 2.13 (95% CI 1.86 to 2.42)). There was no difference in lung function or in adverse effects reported between the treatments.

AUTHORS' CONCLUSIONS

In subjects with chronic bronchitis or COPD, treatment with mucolytics was associated with a small reduction in acute exacerbations and a reduction in total number of days of disability. Benefit may be greater in individuals who have frequent or prolonged exacerbations, or those who are repeatedly admitted to hospital with exacerbations with COPD. They should be considered for use, through the winter months at least, in patients with moderate or severe COPD in whom inhaled corticosteroids (ICS) are not prescribed.

Enfermedad pulmonar obstructiva crónica

Treatment of chronic obstructive pulmonary disease (COPD) has underwent a very important advance in the last five years. It has been developed a new long-lasting anticholynergic drug, tiotrope bromure, which has been found to improve lung function and exercise capacity and to decrease relapses. Also the combined treatment of long lasting beta 2 adrenergics with inhaled steroids (salmeterol/fluticasone and formoterol/budesonide) has proven similar results. However, the response to these new drugs is not the same in all patients. Individual characteristics such as gravity, degree of bronchial hyperresponsiveness, frequency of relapses, comorbidity, etc will determine the response to several agents. Thus, it is necessary to perform a detailed diagnostic study in COPD patients in order to select the best treatment in an individualized form. In the future, new specific antiinflammatories such as phosphodiesterase 4 inhibitors or agents with a potential action in tissue regeneration could lead to new perspectives, as well as to new questions, in COPD treatment.

Increased morbidity associated with chronic infection by an epidemic Pseudomonas aeruginosa strain in CF patients

BACKGROUND

Chronic pulmonary infection with transmissible Pseudomonas aeruginosa strains in individuals with cystic fibrosis (CF) has been reported, raising issues of cross infection and patient segregation. The first such strain to be described (the Liverpool epidemic strain, LES) is now widespread in many UK CF centres. However, whether such infection carries a worse prognosis is unknown. To address this, the clinical course of a group of CF patients chronically infected by LES was compared with that in patients harbouring unique strains.

METHODS

Using P aeruginosa strain genotyping, two cohorts of CF patients attending the Liverpool CF service were identified who were LES positive or negative in 1998 and remained so until 2002. From these, two groups of 12 patients were matched in 1998 for age, spirometric parameters, and nutritional state and their clinical course was followed for 5 years. Patients chronically infected with Burkholderia cepacia were excluded.

RESULTS

Patients chronically infected with LES had a greater annual loss of lung function than those not chronically infected by LES (mean difference between groups -4.4% (95% CI -8.1 to -0.9; p<0.02)), and by 2002 their percentage predicted forced expiratory volume in 1 second (FEV1) was worse (mean 65.0% v 82.6%, p<0.03). Their nutritional state also deteriorated over the study period (mean difference between groups in body mass index -0.7 (95% CI -1.2 to -0.2; p<0.01)), such that by 2002 they were malnourished compared with LES negative patients (mean BMI 19.4 v 22.7, p<0.02).

CONCLUSIONS

Chronic infection with the Liverpool epidemic P aeruginosa strain in CF patients confers a worse prognosis than infection with unique strains alone, confirming the need for patient segregation. Since this strain is common in many CF units, strain identification in all CF centres is essential. This can only be carried out using genomic typing methods.