Responder analysis of keishibukuryogan for the symptoms of Yusho certified patients

Background: Yusho is a 1968 mass food poisoning that was caused by the ingestion of rice oil contaminated with dioxins and related organochlorines. We previously reported that keishibukuryogan (KBG) administration was effective for improvement of the symptoms of Yusho patients. This study used responder analysis to more deeply elucidate the effectiveness of KBG. Method: The data analyzed in the study were collected from our previous clinical study done to predict response to KBG treatment. The patients were divided into responders and non-responders based on whether their symptoms improved after taking KBG. We assessed baseline patient characteristics and the intensity of general fatigue and dermatological, neurological, and respiratory symptoms. Further, we used SF-36 to evaluate Quality of Life (QOL). Results: Of the 42 patients who completed the previous study, 27 were responders and 15 non-responders, with no significant differences in the patient characteristics. The general fatigue, dermatological symptoms, and respiratory symptoms of responders were significantly improved at month 3 of treatment. Analysis of the eight QOL domain profiles of SF-36 showed that the general health of responders was significantly improved from baseline to month 3 compared with non-responders, as was vitality from baseline to month 1. Moreover, the mental health of responders significantly improved from baseline to months 1 and 3. Conclusions: Keishibukuryogan was not only effective for symptoms such as general fatigue, dermatological symptoms, and respiratory symptoms, but also for the mental health of Yusho patients, which indicates that it would be a good first-choice Kampo medicine for the treatment of these patients.