Efficacy and Safety of Bojungikgi-Tang for Persistent Allergic Rhinitis: A Study Protocol for a Randomized, Double-Blind, Placebo-Controlled, Phase II Trial

Background. Allergic rhinitis (AR) is a common disease, and conventional medications are often insufficient for treatment. Bojungikgi-tang (BJIGT) is an herbal medicine widely used in traditional medicine and has anti-inflammatory and immunoregulatory effects. We hypothesize that BJIGT would improve nasal symptoms in patients with persistent AR (PAR). Methods. This is a randomized, double-blind, placebo-controlled, phase II trial. A total of 105 patients, identified with perennial allergens, with a history of PAR and a mean total nasal symptom score (TNSS) >= 5 during the run-in period will be recruited from Daejeon Korean Medicine Hospital. Participants will be randomly assigned to a high-dose BJIGT group, standard-dose BJIGT group, or control group (placebo) in a 1 : 1 : 1 allocation ratio after a week run-in period. The treatment medication will be taken three times per day for 4 weeks. The primary outcome measure is the mean change in the TNSS before and after medication. The secondary outcome measures include the Korean Allergic Rhinitis-Specific Quality of Life Questionnaire, total IgE and eosinophil count, overall assessment of AR, pattern identification questionnaire for AR, and Sasang constitution. Discussion. The aim of this study is to investigate the efficacy and safety of BJIGT in the treatment of PAR and to determine the suitable dosage of BJIGT. Therefore, we planned a randomized, controlled, phase II trial of two different doses of BJIGT compared with placebo, and the results of this study are expected to provide evidence for the use of BJIGT as a treatment of PAR.