Efficacy of the 5-HT1A agonist tandospirone citrate in improving symptoms of patients with functional dyspepsia: a randomized controlled trial.

OBJECTIVES: Functional dyspepsia (FD) is a common condition in the general population; however, its treatment remains a challenge. The aim of this study was to examine the efficacy of tandospirone citrate, a new partial agonist of the 5-hydroxytryptamine 1A (5-HT1A) receptor, in improving the symptoms of patients with FD. METHODS: In this double-blind, placebo-controlled, multicenter study, FD patients were randomized to treatment with 10 mg t.i.d. tandospirone citrate or to placebo for 4 weeks. The primary end point was change in abdominal symptom scores. The difference in the proportion of responders (a total abdominal symptom score of 0 or 1) was also assessed. The quality-of-life questionnaire, the SF-8, and a psychological test questionnaire, the State-Trait Anxiety Inventory (STAI), were completed at baseline and at weekly intervals. RESULTS: Data were available for 144 patients: 73 for tandospirone and 71 for placebo. Improvements in total abdominal scores were significantly larger with tandospirone than placebo at weeks 1, 2, and 4. Significantly greater improvements in the tandospirone group were observed in upper abdominal pain (P=0.02) and discomfort (P=0.002) at week 4. The proportion of responders was significantly greater in the active treatment arm at weeks 3 (P=0.017) and 4 (P=0.0016). Significant improvements in STAI (P<0.0001) were reported in both arms, as well as in the majority of questions in the SF-8 (P=0.04). No serious adverse events were reported, with similar rates in both study arms. CONCLUSIONS: Despite a considerable placebo effect, the benefits of tandospirone were shown in terms of improvement in abdominal symptom scores.