[A pair of crude drugs used in Shang-Han-Lun, especially the ways of using roasted licorice].

The frequency and usage of "Yao-dui" (pair of two kinds of crude drugs, Yaku-tai used in Shang-Han-Lun, a famous formulary in traditional Chinese medicine, was examined. The best ten kinds of pairs of two crude drugs frequently mentioned in the formulary were those among five drugs contained in Guizhi-tang (Keishi-to in Japanese), which is a major formulation in Shang-Han-Lun. Radix Glycyrrhizae Preparata (Sha-kanzo in Japanese) and Ramulus Cinnamomi (Keishi in Japanese) were used in pairs very frequently, which is used for the treatment of palpitation caused by Xin-yang deficiency (Shin-yo-kyo in Japanese) and usually used with Poria. Radix Glycyrrhizae Preparata and Radix Paeoniae worked in pairs for the treatment of muscular spasm and pain due to Xue-deficiency-syndrome (Kekkyo in Japanese). Radix Glycyrrhizae Preparata is used together with Rhizoma Zingiberis (Kankyou in Japanese) for the treatment of diarrhea accompanied with cold pain in the lower abdomen and usually used with Radix Ginseng and Aconiti Preparata. The experimental knowledge of the usage of these crude drug pairs will be useful to create a new formulation of crude drugs for modern medical treatment.