Heterocyclic amides of formula (1) ##STR00001## wherein: X is N or CH; R.sup.4 and R.sup.5 together are either --S--C(R.sup.6).dbd.C(R.sup.7)-- or --C(R.sup.7).dbd.C(R.sup.6)--S--; R.sup.6 and R.sup.7 are independently selected from, for example hydrogen, halo and C.sub.1-4alkyl; A is phenylene or heteroarylene; n is 0, 1 or 2; R.sup.1 is selected from for example halo, nitro, cyano, hydroxy, carboxy; R.sup.2 is hydrogen, hydroxy or carboxy; R.sup.3 is selected from for example hydrogen, hydroxy, aryl, heterocyclyl and C.sub.1-4alkyl(optionally substituted by 1 or 2 R.sup.8 groups); R.sup.8 is selected from for example hydroxy, --COCOOR.sup.9, --C(O)N(R.sup.9)(R.sup.10), --NHC(O)R.sup.9, (R.sup.9)(R.sup.10)N-- and --COOR.sup.9; R.sup.9 and R.sup.10 are selected from for example hydrogen, hydroxy, C.sub.1-4alkyl (optionally substituted by 1 or 2 R.sup.13); R.sup.13 is selected from hydroxy, halo, trihalomethyl and C.sub.1-4alkoxy; 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.