The general pharmacological properties of indolo[2',3':3,4]pyrido[2,1-b]quinazolinium-5,7,8,13-tetrahydro-14- methyl-5-oxo-chloride (dehydroevodiamine-HCl, DHED, CAS 67909-49-3), a new potential anti-dementia agent, were studied to investigate side effects using various experimental animals. Both oral and intraperitoneal administration of DHED had no effects on the central nervous system except that they showed an analgesic activity. DHED had no significant effect on heart rate, blood pressure and coronary flow in isolated rat hearts. DHED had negligible effects on the autonomic nervous system and smooth muscle in isolated rat ileum, rat vas deferens and rat aorta. DHED did not influence the gastrointestinal system except that it inhibited the intestinal travel of a charcoal meal in mice. Neither blood coagulation mechanism nor liver function was affected by DHED. Therefore, it is concluded from these general pharmacological studies that DHED does not induce any serious side effects at the dose levels showing anticholinesterase and memory enhancing activities in the experimental animals.