Chinese medicinal herbs for acute bronchitis

BACKGROUND: Acute bronchitis is one of the most common diagnoses made by primary-care physicians. It is traditionally treated with antibiotics, (although the evidence for their effectiveness is weak and modest at best), and other even less effective treatments. Chinese medicinal herbs have been also used as treatment. OBJECTIVES: This review aims to summarise the existing evidence on the comparative effectiveness and safety of Chinese medicinal herbs for treating uncomplicated acute bronchitis. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005), which includes the Cochrane Acute Respiratory Infections Group's specialised register; The Chinese Cochrane Centre's Controlled Trials Register (up to December 2004); MEDLINE (1966 to March Week 1, 2005); EMBASE (1988 to December 2004); and the Chinese Biomedical Database (CBM) (1980 to December 2004). SELECTION CRITERIA: Randomised controlled trials comparing Chinese medicinal herbs with placebo, antibiotics or other Western medicines for the treatment of uncomplicated acute bronchitis. DATA COLLECTION AND ANALYSIS: At least two authors extracted data and assessed trial quality. MAIN RESULTS: Four trials reported the time to improvement of cough, fever, and rales associated with bronchitis and showed that patients treated with Chinese herbs had a shorter duration of signs and symptoms. Two trials reported the proportion of patients with improved signs and symptoms at follow up and showed that Chinese herbs were beneficial in terms of relief of signs and symptoms. Thirteen trials analysed the data on physician global assessment of improvement at follow up. Nine of thirteen trials showed that Chinese herbs were superior to routine treatment and the other four trials showed a similar effect to routine treatment. In general, Chinese herbs appeared beneficial. Only one trial reported on adverse effects during treatment. AUTHORS' CONCLUSIONS: There is insufficient quality data to recommend the routine use of Chinese herbs for acute bronchitis. The benefit found in this systematic review could be due to publication bias and study-design limitations of the individual studies. In addition, the safety of Chinese herbs is unknown due to the lack of toxicological evidence on these Chinese herbs, though adverse events are rarely reported. Chinese herbs should be used carefully.