Use of mucolytics in COPD: A Delphi consensus study

BACKGROUND

International guidelines recommend mucolytic agents as add-on therapy in selected patients with COPD because they may reduce exacerbations and improve health status. As the evidence varies among mucolytic agents, we used the Delphi method to assess consensus amongst an international panel of COPD experts on mucolytics use in COPD.

METHODS

53 COPD experts from 12 countries were asked to complete an online questionnaire and rate their agreement with 15 statements using a 5-point scale. The mucolytic agents evaluated were carbocysteine, erdosteine and N-acetylcysteine (NAC). Data were collected anonymously and consensus presented using descriptive statistics.

RESULTS

The 47 respondents reached consensus on the statements. They agreed that regular treatment with mucolytic agents effectively reduces the frequency of exacerbations, reduces the duration of mild-to-moderate exacerbations, and can increase the time to first exacerbation and symptom-free time in COPD patients. Consensus was consistently highest for erdosteine. The experts agreed that all three mucolytics display antioxidant and anti-inflammatory activity. Erdosteine and NAC were thought to improve the efficacy of some classes of antibacterial drugs. All three mucolytics were considered effective for the short-term treatment of symptoms of acute exacerbations when added to other drugs. The panel agreed that approved doses of mucolytic agents have favorable side-effect profiles and can be recommended for regular use in patients with a bronchitic phenotype.

CONCLUSIONS

Consensus findings support the wider use of mucolytic agents as add-on therapy for COPD. However, the differences in pharmacological actions and clinical effectiveness must be considered when deciding which mucolytic to use.

A 2 × 2 factorial, randomised, open-label trial to determine the clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care over 52 weeks in adults with bronchiectasis: a protocol for the CLEAR clinical trial

BACKGROUND

Current guidelines for the management of bronchiectasis (BE) highlight the lack of evidence to recommend mucoactive agents, such as hypertonic saline (HTS) and carbocisteine, to aid sputum removal as part of standard care. We hypothesise that mucoactive agents (HTS or carbocisteine, or a combination) are effective in reducing exacerbations over a 52-week period, compared to usual care.

METHODS

This is a 52-week, 2 × 2 factorial, randomized, open-label trial to determine the clinical effectiveness and cost effectiveness of HTS 6% and carbocisteine for airway clearance versus usual care - the Clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care (CLEAR) trial. Patients will be randomised to (1) standard care and twice-daily nebulised HTS (6%), (2) standard care and carbocisteine (750 mg three times per day until visit 3, reducing to 750 mg twice per day), (3) standard care and combination of twice-daily nebulised HTS and carbocisteine, or (4) standard care. The primary outcome is the mean number of exacerbations over 52 weeks. Key inclusion criteria are as follows: adults with a diagnosis of BE on computed tomography, BE as the primary respiratory diagnosis, and two or more pulmonary exacerbations in the last year requiring antibiotics and production of daily sputum.

DISCUSSION

This trial's pragmatic research design avoids the significant costs associated with double-blind trials whilst optimising rigour in other areas of trial delivery. The CLEAR trial will provide evidence as to whether HTS, carbocisteine or both are effective and cost effective for patients with BE.

TRIAL REGISTRATION

EudraCT number: 2017-000664-14 (first entered in the database on 20 October 2017). ISRCTN.com, ISRCTN89040295. Registered on 6 July/2018. Funder: National Institute for Health Research, Health Technology Assessment Programme (15/100/01).

SPONSOR

Belfast Health and Social Care Trust. Ethics Reference Number: 17/NE/0339. Protocol version: v3.0 Final_14052018.

Nebulized and oral thiol derivatives for pulmonary disease in cystic fibrosis

BACKGROUND

Cystic fibrosis is an inherited condition resulting in thickened, sticky respiratory secretions. Respiratory failure, due to recurrent pulmonary infection and inflammation, is the most common cause of mortality. Muco-active therapies (e.g. dornase alfa and nebulized hypertonic saline) may decrease sputum viscosity, increase airway clearance of sputum, reduce infection and inflammation and improve lung function. Thiol derivatives, either oral or nebulized, have shown benefit in other respiratory diseases. Their mode of action is likely to differ according to the route of administration. There are several thiol derivatives, and it is unclear which of these may be beneficial in cystic fibrosis.

OBJECTIVES

To evaluate the efficacy and safety of nebulized and oral thiol derivatives in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, hand searches of relevant journals, abstract books and conference proceedings.Most recent search: 13 June 2013.We also conducted a PubMed search on 26 February 2013 for relevant published articles.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing nebulized or oral thiol derivatives to placebo or another thiol derivative in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

The authors independently assessed trials for inclusion, analysed risk of bias and extracted data.

MAIN RESULTS

Searches identified 23 trials; nine trials (255 participants) are included, of these seven trials are more than 10 years old. Three trials of nebulized thiol derivatives were identified (one compared 20% N-acetylcysteine to 2% N-acetylcysteine; another compared sodium-2-mercaptoethane sulphonate to 7% hypertonic saline; and another compared glutathione to 4% hypertonic saline). Although generally well-tolerated with no significant adverse effects, there was no evidence of significant clinical benefit in our primary outcomes in participants receiving these treatments.Six trials of oral thiol derivatives were identified. Three trials compared N-acetylcysteine to placebo; one compared N-acetylcysteine, ambroxol and placebo; one compared carbocysteine to ambroxol; and one compared low and high-dose N-acetylcysteine. Oral thiol derivatives were generally well-tolerated with no significant adverse effects, however there was no evidence of significant clinical benefit in our primary outcomes in participants receiving these treatments.

AUTHORS' CONCLUSIONS

We found no evidence to recommend the use of either nebulized or oral thiol derivatives in people with cystic fibrosis. There are very few good quality trials investigating the effect of these medications in cystic fibrosis, and further research is required to investigate the potential role of these medications in improving the outcomes of people with cystic fibrosis.

The effect and mechanism of action of carbocysteine on airway bacterial load in rats chronically exposed to cigarette smoke

BACKGROUND AND OBJECTIVE

Carbocysteine (S-carboxymethylcysteine) is a mucoactive drug with in vitro free radical scavenging and anti-inflammatory properties. Several clinical trials have indicated that carbocysteine reduces exacerbation rates in COPD. In the present study, the effect of carbocysteine on the airway load of Haemophilus influenzae was assessed in rats chronically exposed to cigarette smoke (CS). In addition, the effects of carbocysteine on airway mucus hypersecretion and mucociliary clearance (MCC) associated with the adherence and clearance of H. influenzae were investigated.

METHODS

Wistar rats were randomly divided into control, carbocysteine vehicle, CS exposure and carbocysteine treatment groups. After 12 weeks, rats were selected for quantitative inoculation of H. influenzae. BAL fluid and lungs were collected aseptically after 3 h for quantitative culture of H. influenzae. MCC was measured by quantifying the clearance of (99m)Tc-Sc. Goblet cell metaplasia and the presence of mucoid matter were evaluated by Alcian blue/periodic acid-Schiff staining. Mucin 5AC (Muc5AC) expression was detected by western blotting and real-time reverse transcription-PCR.

RESULTS

Exposure to CS increased airway H. influenzae load, aggravated mucus hypersecretion and delayed MCC. Treatment with carbocysteine decreased airway H. influenzae load, and attenuated airway mucus hypersecretion, with improved MCC associated with adherence and clearance of H. influenzae.

CONCLUSIONS

These results suggest that carbocysteine may be beneficial in patients with COPD by increasing the clearance of bacteria and decreasing bacterial load.

Nebulized and oral thiol derivatives for pulmonary disease in cystic fibrosis

BACKGROUND

Cystic fibrosis is an inherited condition resulting in thickened, sticky respiratory secretions. Respiratory failure, due to recurrent pulmonary infection and inflammation, is the most common cause of mortality. Muco-active therapies (e.g. dornase alfa and nebulized hypertonic saline) may decrease sputum viscosity, increase airway clearance of sputum, reduce infection and inflammation and improve lung function. Thiol derivatives, either oral or nebulized, have shown benefit in other respiratory diseases. Their mode of action is likely to differ according to the route of administration. There are several thiol derivatives, and it is unclear which of these may be beneficial in cystic fibrosis.

OBJECTIVES

To evaluate the efficacy and safety of nebulized and oral thiol derivatives in people with cystic fibrosis.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, hand searches of relevant journals, abstract books and conference proceedings.Most recent search: November 2008.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing nebulized or oral thiol derivatives to placebo or another thiol derivative in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

The authors independently assessed trials for inclusion, analysed methodological quality and extracted data.

MAIN RESULTS

Searches identified 18 trials; eight (seven older than 10 years) (234 participants) are included. Three trials of nebulized thiol derivatives were identified (one compared 20% n-acetylcysteine to 2% n-acetylcysteine; another compared sodium-2-mercaptoethane sulphonate to 7% hypertonic saline; and another compared glutathione to 4% hypertonic saline). Although generally well-tolerated with no significant adverse effects, there was no evidence of significant clinical benefit in our primary outcomes in participants receiving these treatments.Five studies of oral thiol derivatives were identified. Three studies compared n-acetylcysteine to placebo; one compared n-acetylcysteine, ambroxol and placebo; and one compared carbocysteine to ambroxol. Oral thiol derivatives were generally well-tolerated with no significant adverse effects, however there was no evidence of significant clinical benefit in our primary outcomes in participants receiving these treatments.

AUTHORS' CONCLUSIONS

We found no evidence to recommend the use of either nebulized or oral thiol derivatives in people with cystic fibrosis. There are very few good quality trials investigating the effect of these medications in cystic fibrosis, and further research is required to investigate the potential role of these medications in improving the outcomes of people with cystic fibrosis.

The role for S-carboxymethylcysteine (carbocisteine) in the management of chronic obstructive pulmonary disease

Prescription of mucoactive drugs for chronic obstructive pulmonary disease (COPD) is increasing. This development in clinical practice arises, at least in part, from a growing understanding of the important role that exacerbation frequency, systemic inflammation and oxidative stress play in the pathogenesis of respiratory disease. S-carboxymethylcysteine (carbocisteine) is the most frequently prescribed mucoactive agent for long-term COPD use in the UK. In addition to its mucoregulatory activity, carbocisteine exhibits free-radical scavenging and anti-inflammatory properties. These characteristics have stimulated interest in the potential that this and other mucoactive drugs may offer for modification of the disease processes present in COPD. This article reviews the pharmacology, in vivo and in vitro properties, and clinical trial evidence for carbocisteine in the context of guidelines for its use and the current understanding of the pathogenic processes that underlie COPD.

A phase II study with antioxidants, both in the diet and supplemented, pharmaconutritional support, progestagen, and anti-cyclooxygenase-2 showing efficacy and safety in patients with cancer-related anorexia/cachexia and oxidative stress

PURPOSE

To test the efficacy and safety of an integrated treatment based on a pharmaconutritional support, antioxidants, and drugs, all given orally, in a population of advanced cancer patients with cancer-related anorexia/cachexia and oxidative stress.

PATIENTS AND METHODS

An open early-phase II study was designed according to the Simon two-stage design. The integrated treatment consisted of diet with high polyphenols content (400 mg), antioxidant treatment (300 mg/d alpha-lipoic acid + 2.7 g/d carbocysteine lysine salt + 400 mg/d vitamin E + 30,000 IU/d vitamin A + 500 mg/d vitamin C), and pharmaconutritional support enriched with 2 cans per day (n-3)-PUFA (eicosapentaenoic acid and docosahexaenoic acid), 500 mg/d medroxyprogesterone acetate, and 200 mg/d selective cyclooxygenase-2 inhibitor celecoxib. The treatment duration was 4 months. The following variables were evaluated: (a) clinical (Eastern Cooperative Oncology Group performance status); (b) nutritional [lean body mass (LBM), appetite, and resting energy expenditure]; (c) laboratory [proinflammatory cytokines and leptin, reactive oxygen species (ROS) and antioxidant enzymes]; (d) quality of life (European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D, and MFSI-SF).

RESULTS

From July 2002 to January 2005, 44 patients were enrolled. Of these, 39 completed the treatment and were assessable. Body weight increased significantly from baseline as did LBM and appetite. There was an important decrease of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha, and a negative relationship worthy of note was only found between LBM and IL-6 changes. As for quality of life evaluation, there was a marked improvement in the European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D(VAS), and multidimensional fatigue symptom inventory-short form scores. At the end of the study, 22 of the 39 patients were "responders" or "high responders." The minimum required was 21; therefore, the treatment was effective and more importantly was shown to be safe.

CONCLUSION

The efficacy and safety of the treatment have been shown by the study; therefore, a randomized phase III study is warranted.

A comparative bioavailability study of a generic capsule formulation containing carbocysteine

The bioequivalence of two carbocysteine capsulae preparations was assessed in 18 healthy volunteers who received a single 750 mg dose of each carbocysteine formulation, and a new sensitive method for the quantification of carbocysteine in human plasma was developed. The study was conducted using an open, randomized, two-sequence, two-period crossover design with a week washout period between the succesive treatments. Plasma samples were obtained over a 12-hour period and analyzed by high performance liquid chromatography coupled to electrospray ionization-mass spectrometry. Either a multiplicative statistic model for concentration-dependent parameters or an additive approach for time-related parameters were used for the comparison of pharmacokinetic parameters describing both the early and total exposure to carbocysteine. The respective 90% confidence limits [CL] of the individual ratios of geometric means were 0.898 to 1.112 [point estimate 0.999] for Cmax and 0.923 to 1.210 [point estimate 1.057] for AUC(0-infinity), while the difference between times elapsed to reach Cmax was insignificant [p = 0.4497]. Since both 90% CL for the log-transformed AUC(0-infinity) and Cmax geometric mean ratios were included in the proposed 0.80-1.25 interval, test drug (Bronchobos capsules) was considered bioequivalent to the reference one (Mucopront capsules).

Exhaled Interleukine-6 and 8-isoprostane in chronic obstructive pulmonary disease: effect of carbocysteine lysine salt monohydrate (SCMC-Lys)

Chronic obstructive pulmonary disease (COPD) is characterized by an airways inflammation and by an enhanced generation of reactive oxygen species. The aim of our study was to assess the inflammation and the oxidative stress in airways of COPD patients with acute exacerbation of disease and in stability. Furthermore, we investigated the anti-inflammatory and antioxidant effects of 6 months treatment with carbocysteine lysine salt monohydrate (SCMC-Lys) in COPD. We studied 30 mild acute COPD, 10 mild stable COPD and 15 healthy subjects. 8-isoprostane and Interleukine-6 were measured in their breath condensate through immunoassay. Significantly higher concentrations of exhaled 8-isoprostane and Interleukine-6 were found in acute COPD patients compared to stable COPD and healthy controls (21.8+/-5.1 vs. 13.2+/-2.0 vs. 4.7+/-1.8 pg/ml and 7.4+/-0.9 vs. 5.8+/-0.2 vs. 2.7+/-0.6 pg/ml, p<0.0001). COPD patients treated with SCMC-Lys showed a marked reduction of exhaled 8-isoprostane and Interleukine-6 (8.9+/-1.5 and 4.6+/-0.8 pg/ml, p<0.0001). These findings suggest that there is an increase of 8-isoprostane and Interleukine-6 concentrations in the breath condensate of COPD patients compared to healthy controls especially during acute exacerbations of the disease. Moreover, we showed an anti-inflammatory and antioxidant effect of short-term administration of SCMC-Lys in COPD, suggesting the importance of a further placebo-controlled study that should evaluate the effects of this drug.

The effect of cysteine analogues on the excretion of urinary sulphate in the rat following cysteine administration

A major pathway for the production of sulphate within the mammalian body is known to be via the oxidative degradation of the sulphur moiety within the amino acid, L-cysteine. The ability of two structurally similar sulphur-containing drugs, the anti-rheumatic agent, D-penicillamine, and the mucoactive compound, S-carboxymethyl-L-cysteine, to interfere with this sulphate production was investigated. Co-administration to the male rat of D-penicillamine (p.o.) and S-carboxymethyl-L-cysteine (p.o.) with [35S]-L-cysteine (i.p.) led to a significant decrease in the subsequent urinary elimination of inorganic sulphate whilst having no measurable effect on organic sulphate excretion. The co-administration of L-valine, an amino acid not containing sulphur, had no effect. It is not known where, within the complex sequence of events surrounding the degradation of cysteine to sulphate, that D-penicillamine or S-carboxymethyl-L-cysteine may interact.

Thirty-five cases of S-carboxymethylcysteine use in paraquat poisoning

The herbicide paraquat is associated with a high mortality rate. It produces multiorgan damage through the induction of acute oxidative stress, by generation of reactive oxygen species that cause oxidative damage to biomolecules. In addition to general supportive measures, the management of paraquat poisoning includes gastric washing, forced diuresis, haemodialysis and the use of antioxidants, such as N-acetylcysteine. However, this drug is rather unavailable in Venezuela and S-carboxymethylcysteine has been used. We report 35 patients with mild to severe paraquat poisoning, which beside standard supportive treatment received 1500 mg S-carboxymethylcysteine, up to 2-3 w. The mortality rate was 22.86% (8 deaths/35 cases) and was related to the severity of paraquat poisoning (as assessed by urine dithionite tests). We conclude that S-carboxymethylcysteine is a reliable alternative in managing patients with paraquat poisoning.

Effects of carbocysteine on antigen-induced increases in cough sensitivity and bronchial responsiveness in guinea pigs

Carbocysteine is a mucoactive drug and is being used for both acute and chronic infectious airway diseases. Although carbocysteine can repair the damage of epithelial cells caused by exposure to various agents, the effects of this agent on allergic airway diseases such as asthma and eosinophilic bronchitis with an isolated chronic cough, in both of which epithelial damage may be characteristic, is not clear. We investigated the effects of carbocysteine on antigen-induced cough hypersensitivity to inhaled capsaicin at 48 h and bronchial hyperresponsiveness to inhaled methacholine at 72 h after challenge with an aerosolized antigen in actively sensitized guinea pigs. After measuring bronchial responsiveness, we examined neutral endopeptidase (NEP) activity in the tracheal tissue. Carbocysteine (10, 30, or 100 mg/kg) was given intraperitoneally every 12 h for 3 days after antigen challenge. The number of coughs elicited by an aerosol of capsaicin (10(-4) M) was significantly (p < 0.01) decreased in carbocysteine groups (6.13 +/- 0.59 at 10 mg/kg, 4.88 +/- 0.67 at 30 mg/kg, and 4.50 +/- 0.33 at 100 mg/kg during 3 min measurement) compared with the control group (9.75 +/- 0.53). Furthermore, carbocysteine dose dependently repaired the antigen-induced decrease of NEP activity in the tracheal tissue, but it did not influence the bronchial hyperresponsiveness or bronchoalveolar lavage cell component. These findings suggest that carbocysteine promotes the repair of damaged epithelium by allergic reaction and may be useful in allergic airway diseases accompanied by isolated chronic coughing, especially eosinophilic bronchitis without asthma and tracheobronchitis with cough hypersensitivity.

Diurnal variation in the metabolism of S-carboxymethyl-L-cysteine in humans

The routes of metabolism of S-carboxymethyl-L-cysteine in humans are dependent on the time of dosing. Administration of 750 mg of S-carboxymethyl-L-cysteine (Day 1) during the day at 8:00 AM followed by a 8:00 AM to 4:00 PM urine collection revealed that S-carboxymethyl-L-cysteine S-oxide was the major urinary metabolite produced. The 4:00 PM to midnight urine collection resulted in S-(carboxymethylthio)-L-cysteine being identified as the major urinary metabolite. However, the administration of 750 mg of S-carboxymethyl-L-cysteine (day 15) during the night at midnight and analysis of the midnight to 8:00 AM urine collection found that thiodiglycolic acid was the major urinary metabolite, whereas thiodiglycolic S-oxide was identified as the major urinary metabolite in the 8:00 AM to 4:00 PM urine collection. A diurnal variation in the metabolism of S-carboxymethyl-L-cysteine was seen and, in particular, the timing of S-carboxymethyl-L-cysteine administration had a profound effect on the identity of urinary S-oxide metabolites produced. After administration at 8:00 AM the urinary S-oxides produced were S-carboxymethyl-L-cysteine S-oxide and S-methyl-L-cysteine S-oxide but at midnight the major urinary S-oxide metabolite produced was thiodiglycolic acid S-oxide.

Clinical efficacy of an antiallergic drug on otitis media with effusion in association with allergic rhinitis

OBJECTIVE

The effect of azelastine hydrochloride (AZ), an oral antiallergic drug, was evaluated in patients displaying otitis media with effusion (OME) accompanying allergic rhinitis.

METHODS

A total of 53 patients diagnosed with OME accompanied by symptomatic perennial allergic rhinitis were randomized to receive in an open fashion 2 mg of AZ in combination with 750 mg of S-carboxymethyl cysteine (SCMC) per day, or 750 mg of SCMC only (controls) for 8 weeks. Efficacy was assessed according to the global improvement rating (GIR) of six nasal or four ear symptoms or signs.

RESULTS

Patients treated with AZ and SCMC had superior improvements in their nasal symptom GIRs compared to controls overall across the 8 week trial, but not in their ear symptom GIRs. However, the clinical course of patients treated with AZ and SCMC tended to be better than that of patients treated with SCMC only, and the nasal and ear symptom GIRs were significantly correlated in the AZ-treated group.

CONCLUSION

These data suggest that AZ may not provide direct efficacy on the ear symptoms in OME patients with allergic rhinitis, but that there might be a possibility of its indirect efficacy in the patients in part by relieving the allergic rhinitis.

Nebulization of S-carboxymethylcysteine does not adversely affect the mucociliary system in the paranasal sinus and trachea of the healthy rabbit

Chronic sinusitis is a persistent inflammatory impairment of the paranasal sinus. Disturbance of the mucociliary function in the paranasal sinus is the most common finding in chronic sinusitis. S-carboxymethylcysteine (S-CMC) has been shown to directly enhance the ciliary activity of the chronic sinusitis mucosa. Direct contact of the disturbed cilia with S-CMC may recover the reduced beating activity of cilia in chronic sinusitis and the mucosal pathology of the disease can thus be improved. Before S-CMC as medicine for nebulization in the treatment of chronic sinusitis can be clinically applied, however, it should be experimentally established whether nebulization of S-CMC has any adverse effects on the mucociliary system of the respiratory mucosa. The present study was designed to experimentally examine the safety of nebulization of S-CMC especially with regard to the respiratory mucosa. Rabbits were treated with nebulization of three different concentrations of S-CMC solution for 20 min a day for 14 successive days, and their mucosal pathology of the sinus and trachea was examined and compared with that of healthy animals. Nebulization of concentrations of 0.5-10% of S-CMC solution did not affect the ciliary activity in the sinus and tracheal mucosa, nor did this treatment induce pathological changes such as epithelial injury and inflammatory cell accumulation. It is therefore concluded that concentrations of 0.5-10% S-CMC solution are quite safe for the use of nebulization in the treatment of chronic sinusitis.

[Decongestant nasal spray. Results of a rhinomanometric double-blind study]

Between november 1993 and july 1995 60 patients with a common cold underwent randomized and double-blind testing of 3 commercial nasal sprays-benzydamine, xylometazoline combined with the secretolytic S-carboxymethylcysteine, and phenylephrine combined with the antihistaminic dimethindene maleate. After prior active rhinomanometric measurement of the untreated nose, the test substance was applied. The change of nasal patency was registered after 3 and 10 minutes and then after 2, 4, 6 and 8 hours. At the end the patient gave a subjective evaluation of the used spray. There was no change in nasal obstruction following application of NaCl or benzydamine. Xylometazoline/S-carboxymethylcysteine (+87%) or phenylephrine/ dimethindene maleate (+113%) augmented nasal patency within minutes. Using phenylephrine/dimethindene maleate the effect lasted less than 2 hours, while after xylometazoline/S-carboxymethylcysteine decongestion lasted more than 6 hours. The patients also subjectively reported an increase in nasal patency after the use of benzydamine and placebo. But only phenylephrine/ dimethindene maleate or xylometazoline/S-carboxymethylcysteine were judged good. Using benzydamine or phenylephrine + dimethindene maleate, more side-effects (mainly dryness and burning) were mentioned. Considering the subjective assessment of side-effects and duration of action, as well as objective parameters, derivatives of imidazole (oxymetazoline and xylometazoline) are first choice in treatment of the common cold.

[Inhalation and peroral mucolytic therapy in mucoviscidosis in children]

The paper summarizes the results of clinical studies of 98 children with mucoviscidosis whose age was 7 to 18 years. There is research evidence for possibility and expediency of using new classes of mucolytic agents in the therapy of mucoviscidosis in children. Analysis of the rheological properties of sputum showed the advantage of inhalation route of mucolytics over their oral administration. There is evidence for the advantage of mucosolvan over carbocysteine and unithiol via all routes of administration, the optimal methods of administration and differentiated indications have been developed.

Otitis media with effusion and S-carboxymethylcysteine and/or its lysine salt: a critical overview

An overview of the placebo-comparative articles retrieved by a literature search on Medline - Embase - Biosis data banks from 1972 to 1993 was performed to evaluate the therapeutic relevance of the medical treatment with S-carboxymethylcysteine (SCMC) and its monohydrate lysine salt (SCMC-LYS) in patients with otitis media with effusion (OME). Ten original published studies were reviewed by an independent physician who assessed their quality by standard nine-items methodology. A meta-analytical approach was used to compare outcomes across all qualifying studies. Because of the heterogeneity of clinical endpoints, a new outcome measure was defined, i.e. overall clinical improvement, which consisted of the number of patients with complete resolution of clinical signs and symptoms and no need for surgical intervention. The objective evaluation criteria of normalisation of tympanogram was an additional end-point. Potential confounding variables such as eligibility criteria, treatment protocol and study design of the six methodologically complying studies were statistically homogeneous. No association was found between treatment effect-size and publication date or patients' age. Outpatients with disease duration of < 6 months, not previously treated, with bilateral ear involvement were included in the studies; half of them presented hyperplasia or hypertrophy of the pharyngeal or the adenoid tissue. Out of 483 patients, 430 (89%) terminated studies and were evaluable. Results from this meta-analysis indicate that patients with OME receiving oral SCMC/-lys benefit from the medical treatment to the extent of avoiding surgical intervention approximately 2.31 times more often than similar patients receiving placebo (ratio of active drug to placebo-effect on overall clinical improvement: 2.31; C.I. 1.28-4.20, P < 0.01) and attain reversion to normal of the tympanogram at an extent close to statistical significance (odds ratio: 2.25, C.I. 0.97-5.22, P = 0.058). In conclusion, the use of this new methodology for the evaluation of the mucoactive drug effect in OME has shed light into methodological pitfalls of clinical trials to date and underlines the need for agreed outcome measures, which may modify medical policy, which addresses more and more often to symptomatic treatment.

Mucolytic activity of azelastine in mice and rats

The mucolytic activity of azelastine, an antiallergic/antiasthmatic drug, in mice and rats was investigated. The oral administration of test compounds 30 min before phenol red i.p. injection stimulated dye secretion in the trachea of mice. The resulting oral ED50's (mg/kg) were: azelastine, 0.16; salbutamol, 2.5; N-acetylcysteine, 61.8; S-Carboxymethyl-l-cysteine, < 100; bromhexine, > 100; and potassium iodide, approximately 200. In rats, several drugs stimulated secretion of fluorescein sodium (FINa) in the tracheobronchial lumen. The resulting oral ED50's (mg/kg) were: azelastine, 0.33; terbutaline, 0.3; salbutamol, 0.89; and S-carboxymethyl-l-cysteine, 56.8. Terfenadine and diphenhydramine (1-10 mg/kg, p.o.) did not stimulate tracheal secretion in rats and mice. The mucolytic activity of azelastine may contribute to its overall effectiveness, including antitussive activity in asthmatics. Finally, this activity seems to be dissociated from its H1-histamine receptor blocking activity.

Effects of S-carboxymethyl-L-cysteine on pulmonary sialyl transferase activity in vitro, in healthy and in sulphur-dioxide-induced bronchitic rats

S-carboxymethyl-L-cysteine (carbocysteine) improves the visco-elastic properties of bronchial mucus in vivo, possibly as a result of an increase in the relative proportions of sialomucins in bronchial mucus. Carbocysteine was therefore studied in vitro and ex vivo in both normal and bronchitic rats on pulmonary sialyl transferase, responsible for the addition of sialic acid to mucus glycoproteins. Bronchitis was induced in male Sprague-Dawley rats by repeated exposure to sulphur dioxide for two weeks. During this time they received either 500 mg kg-1 day-1 carbocysteine or its vehicle by the oral route. Rats not being exposed to SO2 received the same treatment. The animals were then killed, and subcellular fractions prepared by differential centrifugation of lung homogenates. Sialyl transferase was assayed using CMP-14C sialic acid as substrate and desialysed fetuin as exogenous acceptor. Enzyme activity was located in both the (Golgi-containing) 10,000 g and 100,000 g pellets with minor activity in the cytosolic supernatants. When tested in vitro between 10(-6) and 10(-3) M, carbocysteine had no effect on sialyl transferase activity in microsomes taken from healthy or bronchitis rats. Repeated administration of carbocysteine was without effect on the sialyl transferase activity in 10,000 g pellets taken from healthy rats. However, in bronchitic rats there was a small but statistically significant (P less than 0.05) increase in enzymic activity in the treated group compared to the animals receiving the vehicle. There was no difference in the activity of the microsomal enzyme compared to vehicle-treated controls in either healthy or bronchitic rats. We conclude that it is possible that an increase in sialyl transferase activity in a Golgi-containing fraction of bronchitic lungs could explain the relative increase in sialomucins in bronchitic subjects.

Tracing the human metabolism of stable isotope-labelled drugs by ex vivo NMR spectroscopy. A revision of S-carboxymethyl-L-cysteine biotransformation

A direct structural identification, and quantitative assessment below the 50 nmol/ml level, of the full pattern of renally excreted metabolites is made possible by 13C NMR measurements of untreated urine samples when stable isotope-labelled (13C) drug analogues are administered to humans. The full potential of the new ex vivo NMR approach is exemplified by a study, for a group of volunteers, of S-carboxymethyl-L-cysteine metabolism. The metabolic sulphoxidation pathway of S-carboxymethyl-L-cysteine in man, accepted so far, needs to be profoundly revised on the basis of the 13C NMR results.

Effects of myringotomy and orally administered drugs on viscosity and elasticity of middle ear effusions from children with otitis media with effusion

Clinical and rheological studies were performed on 42 children with otitis media with effusion. Twenty-one patients received S-carboxymethylcysteine (group A), and the other 21 patients were administered Kampo medicine (group B), a Japanese traditional herbal medicine, for 4 weeks following myringotomy. At the end of the 4-week treatment period, 47.2% of the ears in group A and 40.5% in group B were regarded as being free from middle ear effusion (MEE). For rheologically thick MEEs, where the viscosity (eta') and elasticity (G') are much greater than the optimal values for mucociliary transport, post-treatment values of eta' for group A decreased significantly, but those of G' did not, in comparison with pre-treatment values. No such changes in either eta' or G' were observed in group B. Results suggests that the combined therapy for myringotomy and oral SCMC is effective for improving the rheological properties of thick MEE in children.

Relative bioavailability of carbocysteine from three dosage forms, investigated in healthy volunteers

The aim of the present study was to evaluate the bioavailability of a new tablet formulation of carbocysteine relative against two other oral carbocysteine containing dosage forms, viz. a syrup and capsules. Plasma levels and urine concentrations of carbocysteine were monitored, following oral administration of all three dosage forms to healthy human volunteers, by direct derivatization of carbocysteine using dabsylchloride and subsequent high performance liquid chromatography. There was no difference in bioavailability of carbocysteine from these dosage forms as expressed by the respective areas under the plasma concentration-time curves and total amounts of unchanged carbocysteine excreted in urine.

Clinical evaluation of S-CMC syrup applied in the treatment of otitis media with effusion. Double blind comparative test with placebo

We carried out a double blind comparative trial with placebo serving as control using 250 cases of infant otitis media with effusion (OME) in order to objectively evaluate the clinical usefulness of S-carboxymethylcysteine (S-CMC), an oral mucolytic agent, against OME. The results obtained were as follows. 1) Global improvement rate, when judged in items of overall improvement, was 79.8% in S-CMC group and 58.2% in placebo group, S group being significantly better when compared to P. 2) The degree of improvement in each item for evaluation revealed significantly better results in S group compared to P, in both objective findings of the effusion amount and its property, and in audiological findings. 3) Adverse reactions observed in 3 cases (2.5%) in S group and in 2 (1.5%) in P group were not serious, and were eliminated through suspension or discontinuation of the medication. The results obtained suggested the usefulness of S-CMC when used in the treatment of OME.

Bronchial drainage prior to bronchography--a possible modification

Bronchography results were studied in 110 cases between the ages of 14 and 68 years. In each case the mucolytic agent Carbocysteine was used to increase the effectiveness of postural drainage prior to bronchography. Insufficient filling of the bronchial tree occurred in only one case. These results suggest that Carbocysteine increases the effectiveness of postural drainage prior to bronchography and indicates the need for further careful controlled studies.

Comparative bioavailability of S-carboxymethylcysteine from two dosage forms: hard gelatin capsule and syrup

Measurement of plasma concentrations after the oral administration of S-carboxymethylcysteine in two different dosage forms, as a hard gelatin capsule and as a syrup, shows its relative bioavailability from the two formulations to be similar. With the exception of the time required to reach peak concentration, which shows a slight variation attributable to the time taken for the drug to be released from the capsule and to dissolve, parameters such as peak concentration, biological half-life and area under the serum-concentration curve whether from t = 0 to t = 8 h or from t = 0 to t = infinity, are not statistically different. The areas under the plasma-concentration curves between t = 0 and t = 8 h and between t = 0 and t = infinity shows that for a confidence limit of 95 per cent, the mean for the capsular form does not differ by more than 3.3-10.3 per cent from the mean for the syrup.

[Effect of S-carboxymethylcysteine on blood levels of amoxycillin and its diffusion through lung parenchyma and pleural exudate in the rat]

The fixed combination (10 : 3) of amoxycillin and S-carboxymethylcysteine, which is indicated in the therapy of the respiratory tract infections, was given to rats by oral route to determine the blood levels and the concentrations in the pulmonary parenchyma and pleural exudate. In comparison with the antibiotic alone the combination determined higher levels of amoxycillin in the blood (0.5, 1.2 hours after administration) in the homogenized lung tissue (2 hours after administration) and in pleural inflammatory exudate (0.5, 1, 2 hours after administration) caused by intrapleural injection of carrageenan. The enhanced distribution of the antibiotic in the target tissues further supports the clinical usefulness of this combination.

S-carboxymethylcysteine in the fluidification of sputum and treatment of chronic airway obstruction

The clinical results and changes in sputum found in both a short-term inpatient trial and a subsequent long-term outpatient investigation (three-month double-blind controlled study) of 82 patients with chronic bronchitis treated with a new mucolytic agent, S-carboxymethylcysteine (Mucodyne), are reported. Fluidification of sputum with reduction in certain measurements of the viscosity of morning sputum aliquots, associated with improvement in the ability to cough up bronchial secretions, significant increase in sputum volume output, and improvement in ventilation (as estimated by the forced expiratory volume in one second), were observed in both trials as dose-related responses, with an increase in the ease of expectoration and a reduction in cough frequency and dyspnea. Therapy with S-carboxymethylcysteine was well tolerated, and there were no serious adverse effects, either immediate or delayed. We suggest that the effect of the drug in fluidifying sputum may be due to a mucoregulatory mechanism which reverses the sputum macromolecular disturbances seen in chronic bronchitis.

No demonstrable effect of S-carboxymethylcysteine on clearance of secretions from the human lung

The mucolytic efficacy of S-carboxymethylcysteine has been assessed in a double-blind crossover trial in 16 patients with chronic obstructive bronchitis. No significant difference was found between drug and placebo after four or seven days' treatment in the rate of clearance of secretions from the lung. This was measured by external counting of previously inhaled polystyrene tracer particles tagged with technetium-99m (99mTc). Lateral scans across the right chest after inhaling the aerosol showed equal penetration of particles towards the periphery of the lung in drug and placebo runs; this indicated that the airways had not been cleared of mucus by the drug. There was no significant difference between drug and placebo runs in the number of coughs or the weight and radioactive content of sputum voided or raised at the end of the run by chest percussion and postural drainage. Ventilatory capacity was not significantly changed nor was there any subjective improvement in the patients as a result of taking the drug.