Abstract: Acylated pyrido ?3,4-e!-as-triazines of the formula (I), ##STR1## wherein R.sub.1 stands for alkyl, alkoxy, haloalkyl, furyl, pyridyl, phenyl, phenyl-(C.sub.1-4 alkyl) or phyenyl-(C.sub.2-4 alkenyl) optionally substituted. R.sub.2 stands for hydrogen or a group of the formula R.sub.1 --CO--, R.sub.3 stands for hydrogen, a phenyl group or a naphthy6l group optionally substituted, or a phenyl-(C.sub.1-4 alkyl) group, pyridyl group or a C.sub.1-20 alkyl group, and R.sub.4 stands for hydrogen or a group of the formula R.sub.1 --CO--, and R.sub.5 forms together with R.sub.2 or R.sub.4 a valence bond, wherein R.sub.2 or R.sub.4 taking part in forming said valence bond may not have the above meaning, and pharmaceutically acceptable acid addition salts thereof, which are prepared by reacting a pyrido ?3,4-e!-as-triazine of the formula (II) or an acid addition salt thereof ##STR2## R.sub.6 stands for hydrogen, and R.sub.5 forms together with R.sub. and R.sub.