tokens: The drug is known to cause a variety of acute toxic effects , ranging from nausea , restlessness , insomnia , ataxia , slurred speech and nystagmus to mood changes , perceptual alterations , inattention , disorientation and aggressive behavior ( Rammer et al 1988 ; Katona and Watson 1986 ; Isbell and Fraser 1953 ; Devlin et al 1985 ; McCarthy 1971 ; Dodds and Revai 1967 ; Degkwitz 1964 ; Hildebrand et al 1989 ). There have also been two reported fatalities from DM overdoses ( Fleming 1986 ). However , there are no reports describing the effects of chronic abuse .