A plant extract and its modified preparation in functional dyspepsia. Results of a double-blind placebo controlled comparative study

Abstract

To assess the efficacy and safety of the commercially available herbal preparation (Iberogast, STW-5*) containing extracts from bitter candy tuft, chamomile flower, peppermint leaves, caraway fruit, licorice root, lemon balm leaves, angelica root, celandine herbs, milk thistle fruit and its research preparation STW-5-S (without bitter candy tuft) in patients with functional dyspepsia. After a standardized diagnostic work-up and at least 7 days free of medication, 60 patients, diagnosed with functional dyspepsia, were recruited in a multicenter trial and randomly assigned to one of 3 treatment groups (STW-5, STW-5-S or placebo). Each patient received the treatment for 4 weeks. The main outcome variables were the improvement of a gastrointestinal symptom score (GIS), a sumscore consisted of 10 dyspeptic symptoms rated on a Likert scale. Dyspeptic symptoms were assessed at baseline, 2 and 4 weeks after treatment. 60 patients completed the trial (mean age 46.8 years, range 25-70, female 38 patients). Compared with placebo-group both herbal preparations STW-5 and STW-5-S showed a clinically significant improvement of GIS after 2 and 4 weeks of treatment (p < 0.001). No statistically significant difference could be observed between the efficacy of STW-5 and STW-5 S (p > 0.05), but a solid improvement of gastrointestinal symptoms could be achieved earlier with STW-5 than with its research preparation STW-5-S without bitter candy tuft (p = 0.023). In patients with functional dyspepsia, the commercially available herbal preparation STW-5 and its modified dispense STW-5-S tested improved dyspeptic symptoms significantly better than placebo. The extract bitter candy tuft appeared to have an additive effect on dyspeptic symptoms.