Objectives: To investigate if extracts from dried ivy leaves (Hedera helix L.) are effective in the treatment of chronic airway obstruction in children suffering from bronchial asthma.
Design: Systematic review of trials documented in the literature with re-analysis of original data.
Trials: 5 randomized controlled trials investigating the efficacy of ivy leaf extract preparations in chronic bronchitis, 3 of which were conducted in children and met our selection criteria. One compared ivy leaf extract cough drops to placebo, one compared suppositories to drops and one tested syrup against drops.
Main outcome measures: Body-plethysmographic and spirometric measures.
Results: Drops were significantly superior to placebo in reducing airway resistance (primary outcome measure; p = 0.04 two-sided) and descriptively superior in all other 'objective' measures. For syrup and suppositories, at least 54%, resp. 35% of the effect against placebo were preserved.
Conclusions: The trials included in this review indicate that ivy leaf extract preparations have effects with respect to an improvement of respiratory functions of children with chronic bronchial asthma, but more far-reaching conclusions can hardly be drawn because of a meagre database, including the fact that only one primary trial included a placebo control. Further research, particularly into the long-term efficacy of the herbal extract, is needed.