The present invention relates to piperidine derivatives of formula (I): ##STR00001## wherein R represents halogen or C.sub.1-4 alkyl; R.sub.1 represents hydrogen or C.sub.1-4 alkyl; R.sub.2 represents hydrogen, C.sub.1-4 alkyl; R.sub.3 represents hydrogen, 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, C.sub.3-7 cycloalkyl, C(O)R.sub.6 or S(O).sub.2R.sub.6; R.sub.6 represents C.sub.1-4 alkyl or C.sub.3-7 cycloalkyl; m is zero or an integer from 1 to 3; n is an integer from 1 to 3; p is an integer from 1 to 2; X and Y are independently C(O) or CH.sub.2; provided that i) X and Y are not both C(O) and ii) when X and Y are both CH.sub.2 and p is 1, R.sub.5 is not hydrogen, C.sub.1-4 alkyl or C(O)R.sub.6; and pharmaceutically acceptable salts and solvates thereof, the process for their preparation and their use in the treatment of conditions mediated by tachykinins.