The present invention relates to piperidine derivatives of formula (I): ##STR00001## R represents halogen or C.sub.1-4 alkyl R.sub.1 represents C.sub.1-4 alkyl; R.sub.2 or R.sub.3 independently represent hydrogen or C.sub.1-4 alkyl; R.sub.4 represents trifluoromethyl, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, trifluoromethoxy or halogen; R.sub.5 represents hydrogen, C.sub.1-4 alkyl or C.sub.3-7 cycloalkyl; R.sub.6 is hydrogen and R.sub.7 is a radical of formula (W): ##STR00002## or R.sub.6 is a radical of formula (W) and R.sub.7 is hydrogen; X represents CH.sub.2, NR.sub.5 or O; Y represents Nitrogen and Z is CH or Y represents CH and Z is Nitrogen; A represents C(O) or S(O)q, provided that when Y is nitrogen and Z is CH, A is not S(O).sub.q; m is zero or an integer from 1 to 3; n is an integer from 1 to 3; p and q are independently an integer from 1 to 2; and pharmaceutically acceptable salts and solvates thereof. The process for their preparation and their use in the treatment of a condition mediated by tachykinins.