Su1633 Placebo Effects in Functional Dyspepsia: A Preliminary Analysis on Symptoms in an Ongoing Randomized Placebo Controlled Trial

Abstract

Background: Functional dyspepsia (FD) is a common disorder; however no currently available therapy is highly effective and most treatments provide only minimal gain over placebo. Due to the spontaneous fluctuation of disease activity, a considerable proportion of patients experience sufficient relief of symptoms even if treated with medications that are effective in a small subgroup of patients. We examined the efficacy of the herbal preparation STW5 (Iberogast®), esomeprazole and placebo in patients with FD. Methods: In a double-blind, double dummy, randomized study, FD patients (Rome III criteria) received either; esomeprazole (Nexium® 20mg/daily) + placebo; STW5 (20 drops/TID) + placebo; dual therapy or double placebo (“active treatment”) for 4 weeks. Thereafter, clinical responders all received placebo (“placebo treatment”) for 2 weeks. Ongoing responders were reassessed after 2 weeks of “no treatment”. Symptoms and severity (Nepean Dyspepsia Index [NDI-S], Gastrointestinal Symptom Score [GIS] and Leeds Dyspepsia Questionnaire [LDQ]), quality of life (Nepean Dyspepsia Index [NDI-QoL]) and anxiety and depression (Hospital Anxiety and Depression Scale) were assessed. Visceral hypersensitivity was assessed with a nutrient challenge test before and after the 4 weeks of “active treatment”. Blinded data was divided into “nonresponder” and “responder” groups. Results: 70 FD patients (44 females; 48±2 years) have completed the study. 51 (73%) were responders to “active treatment”. Of 51 responders, 18 relapsed during “placebo treatment” (35% treatment withdrawal relapsers) and 20 relapsed on visible treatment cessation (39% placebo withdrawal relapsers); 13 continued with sufficient control of symptoms (26% sustained responders) after 2 weeks of “no treatment”. There were no baseline differences between non-responders and responders in regards to their initial symptom occurrence and severity, quality of life or anxiety or depression. In addition, there were no baseline differences between those that responded or relapsed after “treatment withdrawal” and/or “placebo-withdrawal”. After “active treatment” symptoms and severity decreased in responders, when compared with non-responders and this was matched by an improved quality of life (see table). Anxiety, depression and volume consumed during the nutrient challenge test were not different after “active treatment” between the nonresponders and responders. Conclusions: Thus far, 73% of FD patients respond symptomatically to “active treatment” and report an improved quality of life. However, the treatment(35%) and placebo-withdrawal relapse (39%) rates are also high. Baseline patient characteristics thus far have not been shown to predict response.