Study protocol for daiobotanpito combined with antibiotic therapy for treatment of acute diverticulitis: a study protocol for a randomized controlled trial

BACKGROUND: Colonic diverticular disease has been increasing in prevalence due to the rapidly aging global population, but standard treatment has not changed dramatically in recent years. Daiobotanpito (DBT; Da Huang Mu Dan Tang in Chinese) has been used in medical treatment of acute abdominal abscesses, such as appendicitis or diverticulitis in traditional Japanese (Kampo) medicine for many years, based on more than 3000 years of experience. Prior to this study, a retrospective open-label trial was conducted to compare patients with acute diverticulitis who received oral DBT combined with intravenous antibiotics with those who received intravenous antibiotic alone; it showed a positive effect of DBT on acute diverticulitis. We aim to investigate whether moderate to severe acute diverticulitis shows greater improvement with intravenous antibiotics plus orally administered DBT compared with intravenous antibiotics plus placebo. METHODS: This is a two-group, randomized, double-blind, placebo-controlled, multi-center trial, which is designed to evaluate the efficacy and safety of DBT in patients with moderate to severe diverticulitis treated with intravenous antibiotics. Eligible participants will be randomized to either a treatment group receiving a 10-day oral DBT regimen plus conventional therapy or a control group receiving a 10-day placebo regimen plus conventional therapy. The primary outcome will be success in treating diverticulitis: the success rate will be defined as elimination of abdominal pain within 4 days in all patients, and in patients with fever (body temperature ≧ 37.5 °C) on inclusion into this study, fever relief with reduction in body temperature to < 37.5 °C within 3 days. Secondary endpoints will include the number of hospitalization days, changes in inflammatory response (C-reactive protein (CRP), white blood cell (WBC) and neutrophil counts), fever type, number of days before beginning food intake, recurrence rate (observation for 1 year after registration), and adverse event expression rate. Assessments will be performed at baseline and on the day of discharge. The recurrence rate will be recorded at 1 year after registration. DISCUSSION: This study is expected to provide evidence to support the clinical benefits of DBT in the treatment of acute diverticulitis. It may also provide evidence on the efficacy and safety of DBT in the recurrence of acute diverticulitis. TRIAL REGISTRATION: UMIN-CTR: UMIN000027381. Registered on 27 April 2017. https://upload.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000031377, and changed to jRCTs041180063, registered on 30 July 2019; as a result of the revision of the domestic law in 2018 in Japan.