Review: herbal preparations may improve FEV1 and symptoms in asthma
QUESTION: For patients with asthma, do herbal preparations improve lung function and reduce symptoms?
Studies were identified by searching Medline, the Cochrane Library, and EMBASE/Excerpta Medica from their inception to December 1999 with the terms asthma, herb with various endings, Ayurvedic, and traditional Chinese medicine as well as names of individual herbs. Bibliographies and personal reprint collections were scanned, and experts were contacted.
Randomised controlled trials were included if they studied patients with asthma preferably defined using American Thoracic Society criteria, and if they reported outcomes of lung function tests, FEV1, or airway resistance.
Data were extracted on study characteristics and quality, treatment and control interventions, outcome measures, and results.
17 randomised controlled trials met the inclusion criteria. 6 studied Chinese herbal medicines, 8 studied Indian preparations, 1 evaluated a Japanese herbal preparation, 1 evaluated marijuana, and 1 evaluated dried ivy leaf extract. 14 of the trials scored ≤3 of a maximum of 5 on the …