There is strong evidence for Andrographis paniculata (Chuan Xin Lian) being significantly superior to placebo in alleviating the frequency and severity of cough symptoms.
Most studies showed significant improvements in active treatment group patients with cough-related symptoms. The study by Narimanian et al. showed particularly good results for mucociliary clearance. The sole exception was the trial conducted by Melchior et al.; a pilot study with relatively few patients. All studies reported small numbers of mild adverse effects, including nausea, emesis, vertigo, skin rash and diarrhea, but none required further treatment.
Four trials were assessed quantitatively with regard to changes in the frequency of patients' cough symptoms. In these studies, meta-analysis showed strong evidence that A. paniculata reduced this frequency, although significant heterogeneity was found in the original study results. These 5 trials were also compared with regard to changes in the severity of patients' cough symptoms. The results showed strong evidence for the benefit of phytotherapeutics in this area, although significant heterogeneity was found here, too. These analyses show that A. paniculata is effective in reducing the frequency and severity of patients' cough symptoms.
