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)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 condition mediated by tachykinins.