Cough is a natural mechanism of respiratory tract. However, if cough is exacerbated, it may cause discomfort and disturbance of social activities. Cough may be due to acute bronchitis which causes inflammation of airway, which may persist for weeks. This study was conducted to investigate the effect of combined Marshmallow and Zingiber officinalis on acute bronchitis-induced cough. In this double-blind clinical trial, 60 patients, presenting acute bronchitis symptoms following respiratory infections, were selected by convenience sampling and randomly assigned to two groups of 30 each, case and control. In addition to routine treatment, case group were administered with 15 drops of hydroalcoholic Z. officinalis (40 mg) and Marshmallow (300 mg) extract and control group with 15 drops of placebo every six hours. After 10 days of treatment, coughing, coughing attacks at night, awakening, and chest pain of the patients were examined by a researcher-developed questionnaire and the data were analyzed by chi-square and McNemar's test. After 10 days of treatment, coughing decreased in 80% and 60% of the patients of the case and control groups, respectively (P<0.05), and only 2.7% and 50% of the patients of the case and control groups, respectively, presented chest pain (P<0.05). In patients with acute bronchitis, herbal drop of combined Marshmallow and Z. officinalis caused decrease in coughing attacks and relief of trachite-induced chest pain by decreasing inflammation, and decreased gastrointestinal symptoms due to side effects of bronchodilators and synthetic, anti-inflammatory drugs.
