Dimemorfan (INN) (or dimemorphan) (brand names Astomin, Dastosirr, Tusben), or dimemorfan phosphate (JAN), also known as 3,17-dimethylmorphinan, is an antitussive (cough suppressant) of the morphinan family that is widely used in Japan and is also marketed in Spain and Italy. It was developed by Yamanouchi Pharmaceutical (now Astellas Pharma) and introduced in Japan in 1975. It was later introduced in Spain in 1981 and Japan in 1985.