The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review

Abstract

The role of N-acetylcysteine (NAC) in the treatment of chronic bronchitis is unclear. Since a number of studies have been published on this topic, a systematic review of published studies seems justified.A systematic search (Medline, Embase, Cochrane Library, bibliographies, no language restriction) for published randomized trials comparing oral NAC with placebo in patients with chronic bronchitis was performed. Dichotomous data on prevention of exacerbation, improvement of symptoms and adverse effects were extracted from original reports. The relative benefit and number-needed-to-treat were calculated for both individual trials and combined data.Thirty-nine trials were retrieved; eleven (2,011 analysed patients), published 1976± 1994, were regarded as relevant and valid according to preset criteria. In nine studies, 351 of 723 (48.5%) patients receiving NAC had no exacerbation compared with 229 of 733 (31.2%) patients receiving placebo (relative benefit 1.56 (95% confidence interval (CI) 1.37±1.77), number-needed-to-treat 5.8 (95% CI 4.5±8.1). There was no evidence of any effect of study period (12±24 weeks) or cumulative dose of NAC on efficacy. In five trials, 286 of 466 (61.4%) patients receiving NAC reported improvement of their symptoms compared with 160 of 462 (34.6%) patients receiving placebo (relative benefit 1.78 (95% CI 1.54±2.05), number-needed-to-treat 3.7 (95% CI 3.0±4.9)). With NAC, 68 of 666 (10.2%) patients reported gastrointestinal adverse effects compared with 73 of 671 (10.9%) taking placebo. With NAC, 79 of 1,207 (6.5%) patients withdrew from the study due to adverse effects, compared with 87 of 1,234 (7.1%) receiving placebo.In conclusion, with treatment periods of~12±24 weeks, oral N-acetylcysteine reduces the risk of exacerbations and improves symptoms in patients with chronic bronchitis compared with placebo, without increasing the risk of adverse effects. Whether this benefit is sufficient to justify the routine and long-term use of Nacetylcysteine in all patients with chronic bronchitis should be addressed in further studies and cost-effectiveness analyses. Eur Respir J 2000; 16: 253±262.

The Importance of Chronic Bronchitis in Chronic Obstructive Pulmonary Disease

“…N-acetylcysteine is both a mucolytic and an anti-inflammatory and antioxidant drug (173,174). It is widely prescribed for the treatment of chronic bronchitis in mainland Europe (175) and studies have confirmed that it is effective in reducing the risk of exacerbations and improves symptoms of chronic bronchitis (reducing sputum volume) (176). The use of other mucolytics including carbocysteine, have been reviewed in a recent Cochrane publication (177) of 28 trials.…”

Clinical and pharmacological aspects of bath salt use: A review of the literature and case reports

“…Some systematic reviews and meta-analyses have suggested that NAC prevents exacerbations and improves symptoms in Chronic obstructive pulmonary disease (COPD) patients [94][95][96][97][98] (Table 2), however, probably with little or no effect on the lung function parameters [96].…”

Efficacy of Ascorbic Acid (Vitamin C) and/N-Acetylcysteine (NAC) Supplementation on Nutritional and Antioxidant Status of Male Chronic Obstructive Pulmonary Disease (COPD) Patients

“…Hence, dietary supplementation may be a benefi cial therapeutic intervention in this condition (7). A systematic review on the effect of an antioxidant supplementation, namely NAC among COPD patients, revealed that 48.5% of patients receiving NAC had no exacerbations, compared to 31.2% among the placebo group (8). Five out of nine studies reported that NAC supplementation improved symptoms of 61.4% of the treated patients compared to 34.6% in placebo group.…”