Heterocyclic amides of formula (1) ##STR00001## wherein: R.sup.1 is independently selected from, for example, C.sub.1-6alkyl, C.sub.5-7cycloalkyl, C.sub.5-7cycloalkylC.sub.1-3alkyl, C.sub.1-6alkoxy, C.sub.5-7cycloalkoxy, C.sub.5-7cycloalkylC.sub.1-3alkoxy, heterocyclyl, heterocyclylC.sub.1-3alkyl, heterocyclyloxy or heterocyclylC.sub.1-3alkoxy, R.sup.2 is phenyl or heteroaryl; R.sup.3 is independently selected from hydrogen, halo, nitro, cyano, hydroxy, carboxy, carbamoyl, C.sub.1-4alkyl, C.sub.2-4alkenyl, C.sub.2-4alkyl, C.sub.1-4alkoxy, C.sub.1-4alkanoyl, fluoromethyl, difluoromethyl trifluoromethyl and trifluoromethoxy; or a pharmaceutically acceptable salt or pro-drug thereof; possess glycogen phosphorylase inhibitory activity and accordingly have value in the treatment of disease states associated with increased glycogen phosphorylase activity. Processes for the manufacture of said heterocyclic amide derivatives and pharmaceutical compositions containing them are described.