Abstract: Substituted indoloquinoxalines of the general formula I ##STR1## wherein R.sub.1 represents one of several, preferably 1 to 4, similar or different substituents in the positions 1-4 and/or 7-10, selected from halogen, prefrably Br, lower alkyl/alkoxy group having not more than 4 carbon atoms, trifluoromethyl group, trichloromethyl group;X is a group --(CH.sub.2).sub.n--R.sub.2 wherein R.sub.2 represents a nitrogen containing basic residue such as NH.sub.2, NHR.sub.4 or NR.sub.5 R.sub.6 wherein R.sub.4, R.sub.5 and R.sub.6 independently are lower alkyl or cykloalkyl and n is an integer of from 1 to 4 andR.sub.3 represents hydrogen, lower alkyl/cykloalkyl group having not more than 4 carbon atoms,and the physiologically acceptable addition products of the compounds with acids and halogen adducts, preferably adducts with iodine, iodine monochloride or iodine monobromide.