Effect of carbocisteine on patients with COPD: a systematic review and meta-analysis

BACKGROUND: COPD is the fourth leading cause of death in the world. It is a common, progressive, treatable and preventable disease. The exacerbation of COPD is associated with the peripheral muscle force, forced expiratory volume in 1 second (FEV(1)), the quality of life and mortality. Many studies indicated that the mucoactive medicines could reduce the exacerbations of COPD. This study summarized the efficacy of carbocisteine as a treatment for COPD. METHODS: We searched the randomized controlled trials (RCTs) following electronic bibliographic databases: MedLine, Embase, Cochrane Library and Web of Science. We additionally searched gray literature database: OpenSIGLE. We also additionally searched the clinical trial registers: ClinicalTrials.gov register and International Clinical Trials Registry Platform Search Portal. We used RCTs to assess the efficacy of the treatments. We included studies of adults (older than 18 years) with COPD. We excluded studies that were published as protocol or written in non-English language (Number 42016047078). FINDINGS: Our findings included data from four studies involving 1,357 patients. There was a decrease in the risk of the rate of total number of exacerbations with carbocisteine compared with placebo (−0.43; 95% confidence interval [CI] −0.57, −0.29, P<0.01). Carbocisteine could also improve the quality of life (−6.29; 95% CI −9.30, −3.27) and reduce the number of patients with at least one exacerbation (0.86; 95% CI 0.78, 0.95) compared with placebo. There was no significant difference in the FEV(1) and adverse effects and the rate of hospitalization. INTERPRETATION: Long-term use of carbocisteine (500 mg TID) may be associated with lower exacerbation rates, the smaller number of patients with at least one exacerbation and higher quality of life of patients with COPD.