A serotonin 5-HT3 receptor agonist containing a compound represented by the general formula (1) [R.sup.1, R.sup.3 and R.sup.5 represent hydrogen atom, a lower alkyl group, a lower alkenyl group, a halogen atom, hydroxyl group, amino group, a lower alkoxy group, carboxyl group, carbamoyl group, or nitro group, R.sup.2 and R.sup.4 represent a halogen atom, hydroxyl group, or amino group, R.sup.6 represents hydrogen atom, a lower alkyl group, or a lower alkenyl group, R.sup.7 represents hydrogen atom, a lower alkyl group, a lower alkenyl group, or an aralkyl group, and m and n are integers of 1 to 3] or a physiologically acceptable salt thereof as an active ingredient and having both a serotonin 5-HT3 receptor antagonistic action and a serotonin 5-HT3 receptor activating action. ##STR00001##