Andrographis paniculata (Chuan Xin Lian) for symptomatic relief of acute respiratory tract infections in adults and children: A systematic review and meta-analysis

Introduction Antimicrobial resistance (AMR) is a substantial threat to public health. Safe and effective alternatives are required to reduce unnecessary antibiotic prescribing. Andrographis Paniculata (A. Paniculata, Chuan Xin Lien) has traditionally been used in Indian and Chinese herbal medicine for cough, cold and influenza, suggesting a role in respiratory tract infections (RTIs). This systematic review aimed to evaluate the clinical effectiveness and safety of A. Paniculata for symptoms of acute RTIs (ARTIs). Materials and methods English and Chinese databases were searched from their inception to March 2016 for randomised controlled trials (RCTs) evaluating oral A. Paniculata without language barriers (Protocol ID: CRD42016035679). The primary outcomes were improvement in ARTI symptoms and adverse events (AEs). A random effects model was used to pool the mean differences and risk ratio with 95% CI reported. Methodological quality was evaluated using the Cochrane risk of bias tool; two reviewers independently screened eligibility and extracted data. Results Thirty-three RCTs (7175 patients) were included. Most trials evaluated A. Paniculata (as a monotherapy and as a herbal mixture) provided commercially but seldom reported manufacturing or quality control details. A. Paniculata improved cough (n = 596, standardised mean difference SMD:-0.39, 95% confidence interval CI [-0.67,-0.10]) and sore throat (n = 314, SMD: -1.13, 95% CI [-1.37, -0.89]) when compared with placebo. A. Paniculata (alone or plus usual care) has a statistically significant effect in improving overall symptoms of ARTIs when compared to placebo, usual care, and other herbal therapies. Evidence also suggested that A. Paniculata (alone or plus usual care) shortened the duration of cough, sore throat and sick leave/time to resolution when compared versus usual care. No major AEs were reported and minor AEs were mainly gastrointestinal. The methodological quality of included trials was overall poor. Conclusions A. Paniculata appears beneficial and safe for relieving ARTI symptoms and shortening time to symptom resolution. However, these findings should be interpreted cautiously owing to poor study quality and heterogeneity. Well-designed trials evaluating the effectiveness and potential to reduce antibiotic use of A. Paniculata are warranted.