The invention is concerned with novel pyridopyrimidinone derivatives of formula (I): ##STR00001## wherein R.sup.1 to R.sup.8, X, Y, m and n are as defined in the description and in the claims. The compounds of the present invention are HM74A agonists with improved properties compared to niacin and can be used for the treatment and/or prevention of diseases such as dyslipidemia, atherosclerosis, diabetes, metabolic syndrome, and other related diseases associated with HM74A.