An adenosine incorporation inhibitor and a drug for protecting cardiac muscles or preventing or treating inflammatory edema, each containing as the active ingredient a 1,2,3,4-tetrahydro-2,4-dioxoquinazoline derivative represented by general formula (I) or a pharmacologically acceptable salt thereof, wherein R¹ represents hydrogen, (un)substituted lower alkyl, alkenyl or (un)substituted aralkyl; R², R³, R⁴ and R⁵ represent each independently hydrogen, halogen, amino, mono- or di(lower alkyl) amino, lower alkanoyl amino, nitro, cyano, (un)substituted lower alkyl, hydroxy, lower alkoxy, lower alkylthio, carboxy, lower alkoxycarbonyl, lower alkanoyl, aralkyloxy or lower alkanoyloxy; R⁶, R⁷, R⁸ and R⁹ represent each independently hydrogen, hydroxy, (un)substituted lower alkoxy or aralkyloxy, or alternatively the two adjacent groups among them may be combined together to represent methylenedioxy; R¹⁰ represents hydrogen or lower alkyl; and Y and Z represent each independently N or C-R'', wherein R'' represents hydrogen, (un)substituted lower alkyl or halogen.