Chinese medicinal herbs for influenza: a systematic review

BACKGROUND: Influenza is an acute respiratory communicable disease which can cause high morbidity and mortality in an epidemic. Traditional Chinese medicinal herbs following a particular theory may be a potential medicine of choice. OBJECTIVES: We aim to assess the therapeutic effect and adverse reaction of traditional Chinese medicinal herbs in the treatment of uncomplicated influenza. SEARCH STRATEGY: We searched the Cochrane Library, MEDLINE, EMBASE, CBM, and handsearched the relevant Chinese journals. SELECTION CRITERIA: Randomised and quasi-randomised trials compared with placebo, or with other chemical drugs normally used in care, or various other Chinese medicinal herbs amd chemical drugs with herbal preparations compared with simple chemical drugs were also included. DATA COLLECTION AND ANALYSIS: At least two reviewers extracted data and assessed trial quality. MAIN RESULTS: We included 8 relevant studies, most of which were of low quality. Because of the clinical heterogeneity, we did not perform a summary meta-analysis. Some of the studies showed positive results favouring Traditional Chinese medicinal herb treatment compared to antiviral or antipyretic-analgesic drugs or the combination of them. Only three studies mentioned adverse reactions but no detailed data were acquired in the included studies. REVIEWERS' CONCLUSIONS: The small number of included studies and participants, as well as the low quality of most studies, made the evidence far from conclusive for clinical decision making. More high quality randomised controlled trials (RCTs) with similar interventions are required to strengthen the evidence for the efficacy and safety of certain herbal preparations.