Chinese medicinal herbs for influenza.
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.


OBJECTIVE
To assess the effect of Chinese medicinal herbs in preventing and treating influenza, and to estimate the frequency of adverse effects.


METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2007), 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


METHODS
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.


METHODS
Two review authors independently extracted data and assessed trial quality.


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.


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.
Chen
X Y
XY
West China Hospital of Sichuan University, Department of Clinical Epidemiology, No 17, Ren Min Nan Lu 3 Duan, Chengdu, Sichuan, China, 610041. abilitywin@163.com
Wu
T X
TX
Liu
G J
GJ
Wang
Q
Q
Zheng
J
J
Wei
J
J
Ni
J
J
Zhou
L K
LK
Duan
X
X
Qiao
J Q
JQ
D000547:Amantadine / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D004365:Drugs, Chinese Herbal / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007251:Influenza, Human / Q000188:drug therapy*; D008517:Phytotherapy / Q000009:adverse effects / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D012254:Ribavirin / Q000627:therapeutic use
D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; D012254:Ribavirin; D000547:Amantadine