Meta-analysis: phytotherapy of functional dyspepsia with the herbal drug preparation STW 5 (Iberogast)


Dr J. Melzer, Department of Internal Medicine, Complementary Medicine, University Hospital Zurich, Rämistrasse 100, CH-8091, Zurich, Switzerland.


Background : Despite a long-standing use of herbal drugs with dyspeptic symptoms, little attention has been paid to their clinical evaluation.

Aim : To assess efficacy and safety of the herbal drug preparation STW 5 (containing, e.g. Iberis, peppermint, chamomile) in the treatment of functional dyspepsia.

Methods : Research in electronic databases, consultation of experts and of the producer identified STW 5 (Iberogast) as descriptor in six randomized-controlled trials. The raw data of three placebo-controlled studies which met the selection criteria, were reanalysed and pooled for meta-analysis; one reference-controlled study supported the safety analysis (STW 5: n = 199, control: n = 198).

Results : Pooled data showed verum (n = 138) to be more effective than placebo (n = 135) with regard to the severity of the most bothersome gastrointestinal symptom (P-value: 0.001, odds ratio: 0.22, 95% CI: 0.11–0.47). A fourth randomized-controlled trial showed no significant difference between STW 5 and cisapride. As to safety, adverse events were similar with verum and placebo; no serious adverse events occurred.

Discussions : From the point of view of efficacy and safety, the herbal medicinal product STW 5 appears to be a valid therapeutic option for patients seeking phytotherapy for their symptoms of functional dyspepsia.