Efficacy and Safety of for Relieving Cough: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

To assess the efficacy and safety of Labill () on cough. Cough is a common symptom of upper respiratory tract infections (URTIs) and bronchitis. products are frequently used as over-the-counter cough medications but their efficacy and safety are uncertain. Randomized controlled trials (RCTs) investigating efficacy and safety of for cough were systematically searched in electronic databases till February 2021. Two reviewers independently performed study selection, data extraction, and quality assessment. Clinical outcomes including improvement or resolution of overall cough symptoms, cough frequency (CF), and adverse events (AEs) of were evaluated and analyzed using a random-effects model. Heterogeneity was evaluated using and chi-squared test. Six RCTs with 1,857 participants with cough were included in this study. Most of the included studies used in combination formula (four of six studies). Based on Cochrane's risk of bias criteria, three of six studies (50%) were rated low risk of bias, whereas the remaining were judged as high risk of bias. This study found that products are more effective than placebo in terms of improvement or resolution of overall cough symptoms with relative risk 1.45 (95% confidence interval (95% CI) 1.26-1.67). Whereas all formulae reduced CF with weighted mean difference 0.44 (95% CI 0.28-0.60), when compared with placebo. There are no serious AEs associated with during treatment periods. Mild-to-moderate gastrointestinal symptoms were common AEs reported in a comparable study between and control groups. The findings indicate that products are safe for use in cough related to respiratory diseases such as URTIs and bronchitis. However, their efficacy is minimal and of uncertain clinical importance. Further high-quality studies are still necessary to confirm this finding.