Chinese medicinal herbs for influenza
Abstract
Background
Influenza is an acute respiratory communicable disease which, during epidemics, can cause high morbidity and mortality. Traditional Chinese medicinal herbs, often administered following a particular theory, may be a potential medicine of choice.
Objectives
To assess the effect of Chinese medicinal herbs in preventing and treating influenza, and to estimate the frequency of adverse effects.
Search methods
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 1), which includes the Cochrane Acute Respiratory Infections Review Group specialised register; MEDLINE (January 1966 to January 2007); EMBASE (January 1988 to January 2007); CBM (Chinese Biomedical Database) (January 1980 to January 2007); and the Chinese Cochrane Center's Controlled Trials Register (up to January 2007). We also searched Current Controlled Trials (www.controlled‐trials.com) and the National Research Register (http://www.update‐software.com/National/) for ongoing trials and reference lists of articles. For more information we telephoned and wrote to researchers in the field, as well as trial authors of studies evaluated in the review
Selection criteria
Randomised controlled trials (RCTs) comparing traditional Chinese medicinal herbs with placebo, no treatment, or chemical drugs normally used in preventing and treating uncomplicated influenza patients.
Data collection and analysis
Two review authors independently extracted data and assessed trial quality.
Main results
Two studies involving 1012 participants were reviewed. The methodological quality of both studies was 'poor'. Included RCTs separately compared two medicinal herbs with two different antiviral drugs, precluding any pooling of results. 'Ganmao' capsules were found to be more effective than amantadine in decreasing influenza symptoms and speeding recovery in one study, (in which adverse reactions were mentioned in the amantadine group although no data were reported). There were no significant differences between 'E Shu You' and ribavirin in treating influenza, nor in the occurrence of adverse reaction.
Authors' conclusions
The present evidence is too weak to support or reject the use of Chinese medicinal herbs for preventing and treating influenza. More RCTs with good methodological quality, larger numbers of participants and clear reporting are needed in the future. We recommend that all the clinical trials registered in the Chinese Clinical Trial Register and Chinese journals join in the Joint Statement of Establishing Chinese Clinical Trial Registration and Publishing System.
PICOs
Plain language summary
Chinese medicinal herbs for patients with uncomplicated influenza
Influenza can cause high morbidity and mortality in an epidemic. Many Chinese medicinal herbs are used for this condition. This review assessed the prophylactic and therapeutic effects as well as safety of Chinese medicinal herbs as an alternative and adjunctive medicine to other commonly used drugs for uncomplicated influenza. Two studies involving 1012 participants were included in the review. The trial quality and evidence were poor and do not support or reject the use of any Chinese herbal preparations for influenza. Well‐designed trials are required.
