Azatetracyclic carbonitriles of the formula I ##STR1## in which R.sub.1 is hydrogen, lower alkyl, cycloalkyl-lower alkyl, lower alkenyl or free, etherified or esterified hydroxy-lower alkyl, and X is epoxy, epithio, methylene of a divalent radical of the partial formula ##STR2## in which R.sub.2 is hydrogen or lower alkyl, and salts of such compounds, their preparation, pharmaceutical preparations which contain these compounds and the use thereof.