PROBLEM TO BE SOLVED: To provide a medicinal composition capable of regulating the action of an anthraquinone-based medicament which is an irritative purgative.SOLUTION: This medicinal composition is provided by formulating at least one component selected from the group consisting of vitamin B1, its derivatives and their salts with rhubarb, its extract or its purgative component. It is preferable that the composition is obtained by formulating the rhubarb, its extract or its purgative component in Daio-kanzo-to and the vitamin B1, its derivatives and their salts are thiamine, thiamine disulfide, prosulthiamine, fursulthiamine, etc., and their salts.COPYRIGHT: (C)2013,JPO&INPIT【課題】刺激性下剤であるアントラキノン系薬剤の作用を調節し得る医薬組成物の提供。【解決手段】ダイオウまたはそのエキスもしくは瀉下成分に、ビタミンB1およびその誘導体並びにそれらの塩類からなる群から選択される少なくとも1種の成分を配合してなる医薬組成物。ダイオウまたはそのエキスもしくは瀉下成分が大黄甘草湯に配合されているもの、ビタミンB1およびその誘導体並びにそれらの塩類が、チアミン、チアミンジスルフィド、プロスルチアミン、フルスルチアミン等並びにそれらの塩であるものが好ましい。【選択図】なし