A sugar alcohol and/or trehalose and sucralose are added to a liquid preparation for internal administration or beverage containing dimemorfan and/or a salt thereof. In this manner, it becomes possible to reduce the bitterness inherent in dimemorfan and also reduce stimuli to the throat.於含有二甲啡烷(dimemorfan)及/或其鹽的內服液劑或飲料中,藉由一同添加糖醇及/或海藻糖(trehalose)、及蔗糖素(sucralose),改善二甲啡烷特有的苦味,進而亦減低對喉嚨的刺激。