Herbal Medicine/Phytotherapy

A proportion of pharmaceutical drugs including current bronchodilators are derived from plants.[14] Most of the recent research in this field focused on pharmacological action and in vitro efficacy of herbal remedies. Li et al.,[15] for example, demonstrate a measurable antiinflammatory activity of Australian and Chinese plants. Since herbal medicine has been used for thousands of years in Chinese and Indian medicine (among others), the interest has always been very strong in such natural remedies. A study by Orhan et al.[16] found that 31% of 304 children with asthma had used herbal medicine, and a study by Lanski et al.[17*] found that 45% of children attending an emergency department had used herbal medicine. Until now, there has been no evidence of efficacy of herbal medicine, as pointed out by the systematic review of Huntley and Ernst.[18**] This is mainly because of very heterogeneous, low-quality studies with small patient numbers. The review by Hofmann et al.[19] on the role of dried ivy (Hedera helix L.) in the treatment of children with asthma in three RCTs showed a significant decrease in airway resistance (but only one trial included a placebo control arm). Because of the meager database, no firm statement can be made on the role of dried ivy in asthma. Zhang et al.[20] assessed the efficacy of xiaoqinglong decoction combined with fluticasone in a RCT with 54 patients with mild or severe asthma and found a statistically stronger improvement of lung function (forced expiratory volume in 1 second [FEV1] and resistance) with the combination treatment than with fluticasone alone. Urata et al.,[21] in their double-blind, randomized, crossover study, found a significant improvement of bronchial hyperresponsiveness and respiratory symptoms after 4 weeks of treatment with 2.5 g of TJ-96 (herbal complex Saiboku-to) three times daily versus placebo. Older trials with Tylophora indica showed some efficacy in improving asthma control, but no newer studies with larger samples were published since then. Szelenyi and Brune[22] concluded in their complete review about herbal remedies that there is insufficient evidence to recommend their use as first-line or even adjunctive therapy for asthma.

Astonishing and perhaps frightening is the lack of information about the safety of these remedies and the widespread advertising of such therapies, mainly on the World Wide Web, where uncontrolled information lives freely and uncensored. Herbal remedies that have a biologic activity also have side effects[23] and interactions.[24] For example, Mizushima and Kobayashi[25] published a series of 24 cases of interstitial pneumonitis induced by herbal remedies.

We urgently need high-quality, double-blinded, randomized, placebo-controlled studies on the safety and efficacy of phytotherapy in asthma because almost one third of our patients use it without solid information about the risks, interactions, and real benefit.