An evaluation of the effect of nebulized N-acetylcysteine on sputum consistency

The effect of nebulized N-acetylcysteine on the phlegm of chronic obstructive pulmonary disease: the NEWEST study

BACKGROUND

Phlegm is prevalent symptom in patients with chronic obstructive pulmonary disease (COPD). Few studies have investigated the effectiveness of N-acetylcysteine (NAC) nebulizer therapy in COPD patients. We evaluated the effect of nebulized NAC on the improvement of phlegm symptom in COPD patients.

METHODS

This was a 12-week, prospective, single-arm, open-label, phase IV multi-center trial (NCT05102305, Registration Date: 20-October-2021). We enrolled patients aged ≥ 40 years with post bronchodilator forced expiratory volume in one second/forced vital capacity (FEV1/FVC) < 0.7 and COPD assessment test (CAT) phlegm score ≥ 2; the patients were current or ex-smoker with smoking pack-years ≥ 10. The primary endpoint was to determine the change in CAT phlegm score at 12 weeks compared to the baseline. Patients were assessed at baseline, 4, 8, and 12 weeks of treatment using the CAT score.

RESULTS

In total, 100 COPD patients were enrolled from 10 hospitals. The mean age of the patients was 71.42 ± 8.20 years, with 19.78% being current-smokers and 80.22% being ex-smokers. The mean smoking pack-years was 40.32 ± 35.18. The mean FVC, FEV1, and FEV1/FVC were 3.94 L (75.44%), 2.22 L (58.50%), and 0.53, respectively. The CAT phlegm score at baseline was 3.47 ± 1.06, whereas after 12 weeks of nebulized NAC it significantly decreased to 2.62 ± 1.30 (p < 0.01). More than half (53.5%) of the patients expressed satisfaction with the effects of nebulized NAC therapy. Adverse events occurred in 8 (8.0%) patients. Notably, no serious adverse drug reactions were reported.

CONCLUSION

In this study, we have established the effectiveness and safety of nebulized NAC over 12 weeks.

The effect of N-acetyl cysteine on the volume of uterine leiomyoma: A randomized clinical trial

OBJECTIVE

To conduct a clinical trial to investigate the effect of N-acetyl cysteine (NAC), a non-hormonal drug, on the volume of leiomyoma, the most common benign tumor in women.

METHODS

This study is a randomized clinical trial, which was performed in Semnan, Iran. Eligible women who were diagnosed with uterine leiomyoma using vaginal ultrasound were randomly assigned to receive NAC or placebo for 12 weeks. The change in the volume of Leiomyoma was considered to be the main variable in the efficacy evaluation. Reduction in the leiomyoma volume was calculated after intervention and data were entered in SPSS version 23.

RESULTS

Fifty individuals were enrolled in our study. 25 women received NAC, while 25 women took placebo. The mean volume of leiomyoma in group A was 5.71 cm³ and in group B was 6.56 cm³ . The mean rate of volume reduction in the A and B groups was 25.25 % and 1.08 %, respectively, which demonstrated a significant difference between the two groups (P < 0.004).

CONCLUSION

Although this trial recommends the use of NAC as a non-hormonal drug in the treatment of leiomyoma of the uterus, the possibility of treatment failure in controlling abnormal uterine bleeding cannot be ignored. Nevertheless, we can say it is feasible and effective in the reduction of leiomyoma volume.

Intratracheal N-acetylcysteine use in infants with chronic lung disease

To evaluate the effect of intratracheal administration of N-acetylcysteine (Mucomyst) on the clinical status, pulmonary function and gas exchange in premature infants with chronic lung disease, we conducted a randomized, placebo-controlled, crossover trial. Ten mechanically ventilated infants (gestational age 27 +/- 1 week; postnatal age 22 +/- 6 days) with clinical and radiological evidence of chronic lung disease and increased airway secretion were enrolled in the study. Each infant received tracheal administration of 5% N-acetylcysteine for one week and saline placebo every 4 h for another week. N-acetylcysteine was associated with a 59 +/- 26% increase in total airway resistance by the third day of treatment (p less than 0.01). A two-fold increase in airway resistance associated with an increased frequency of bradycardia and cyanosis spells was seen in two of the infants following three days of N-acetylcysteine administration, with a rapid improvement in their condition when subsequently switched to saline. Overall, N-acetylcysteine administration had no effect on the variables measured. We conclude that intratracheal administration of N-acetylcysteine to liquefy airway mucus neither improves the clinical condition nor hastens recovery in premature infants with chronic lung disease and its administration may lead to increased total airway resistance and cyanotic spells. The present data do not support the use of N-acetylcysteine as a mucolytic agent in premature infants with chronic lung disease.

A double-blind parallel study of acetylcysteine-isoproterenol and saline-isoproterenol in patients with chronic obstructive lung disease

A double-blind parallel study in patients with asthma compared the safety and efficacy of saline-isoproterenol (SI) and acetylcysteine-isoproterenol (AI), when administered at home as an aerosol, over a one-week period, using a conventional nebulizer compressor. Measurements of pulmonary function revealed statistically significant differences between the two therapies for FEV1 and FVC in favour of AI. In the group treated with AI, the average sputum viscosity after six days of treatment was significantly less than pre-treatment values, or when compared to the results with SI treatment. No serious side-effects were reported during treatment with either therapy. These results indicate that acetylcysteine combined with a bronchodilator, such as isoproterenol, may be safe and of significant value in the treatment of patients with asthma who are also sputum producers.

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.

Clinical and physiological evaluation of mucolytic agents nebulized with soproterenol: 10 per cent N-acetylcysteine verus 10 per cent 2-mercaptoethane sulphonate

In a controlled five-week cross-over study in 12 patients with chronic bronchitis, the effects of nebulized 10% N-acetylcysteine plus isoproterenol were compared with a new drug, sodium 2-mercaptoethane sulphonate, in 10% concentration also nebulized with isoproterenol. Both combinations were compared with a control aerosol of saline and a second control aerosol of saline plus isoproterenol. Both 10% 2-mercaptoethane sulphonate and 10% N-acetylcysteine were highly effective in thinning mucoid, mucopurulent or purulent sputum. Subjective improvement in these patients, however, was related to the isoproterenol rather than to the mucolytic agents. When nebulized with isoproterenol, neither mucolytic agent was associated with bronchospasm in any patient. Physical findings, spirometric values, and sputum volume were unaffected by these mucolytic agents.

Rheological assessment of mucolytic agents on sputum of chronic bronchitics

In vitro and in vivo studies were made on the sputum of chronic bronchitics using a Ferranti-Shirley cone and plate viscometer and a new stress relaxation method. The latter utilized a modified chemical balance and permitted study at very low shear rates. The results from simpler apparatus correlated well with the data obtained with the cone and plate viscometer. Significant reduction in four chosen parameters of viscosity occurred in vitro with N-acetylcysteine and with ascorbic acid-hydrogen peroxide-cupric ion complex (A.A.H.Cu.), but not with 4-molar urea. In vivo studies showed that, using freshly prepared A.A.H.Cu in an efficient hospital nebulizer, a statistically significant reduction in the four viscosity parameters occurred with subjective ease of expectoration. Nebulization of A.A.H.Cu performed with a simpler domestic-type nebulizer did not produce satisfactory reduction of viscosity or ease of expectoration. Rheological methods previously employed to study mucus and mucolytic agent activity are briefly reviewed.