Post-marketing Re-evaluation of Tongxiening Granules () in Treatment of Diarrhea-Predominant Irritable Bowel Syndrome: A Multi-center, Randomized, Double-Blind, Double-Dummy and Positive Control Trial.

Objective: To evaluate the efficacy and safety of Tongxiening Granules (, TXNG) in the treatment of irritable bowel syndrome with predominant diarrhea (IBS-D).

Methods: A randomized, double-blind, double-dummy, and positive parallel controlled clinical trial was conducted from October 2014 to March 2016. Totally 342 patients from 13 clinical centers were enrolled and randomly assigned (at the ratio of 1:1) to a treatment group (171 cases) and a control group (171 cases) by a random coding table. The patients in the treatment group were administered orally with TXNG (5 g per time) combined with pinaverium bromide Tablet simulator (50 mg per time), 3 times per day. The patients in the control group were given TXNG simulator (5 g per time) combined with pinaverium bromide Tablets (50 mg per time), 3 times per day. The treatment course lasted for 6 weeks. The improvement of Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) was used to evaluate the primary outcome. Secondary outcomes included adequate relief (AR) rate, Irritable Bowel Syndrome-Quality of Life Questionnaire (IBS-QOL), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), and the recurrence rate at follow-ups. Safety indices including the adverse events (AEs) and related laboratory tests were evaluated.

Results: Primary outcome: IBS-SSS at baseline, weeks 2, 4, 6 showed no statistical significance in both full analysis set (FAS) and per protocol set (PPS, P>0.05). After 6 weeks of treatment, the total effective rate of IBS-SSS scores in the treatment group (147/171,86.0%) was higher than the control group (143/171, 83.6%) by FAS (P>0.05). In regard to secondary outcomes, after 6-week treatment, there was no significant difference in AR rate, total score of IBS-QOL, improvement of HAMD and HAMA total scores between the two groups (P>0.05). The recurrence rate at 8-week follow-up was 12.35% (10/18) in treatment group and 15.79% (12/76) in control group, respectively (P>0.05). A total of 21 AEs occurred in 15 cases, of which 11 occurred in 8 cases in the treatment group and 10 AEs in 7 cases in the control group. The incidence of AEs had no statistical significance between the two goups (P>0.05).

Conclusion: Tongxiening Granules could relieve the symptoms of patients with IBS-D and the treatment effect was comparable to pinaverium bromide. (No. ChiCTR-IPR-15006415).