A group of new piperazine and piperidine compounds having interesting advantageous pharmacological properties and have the formula (a) ##STR1## wherein A represents a heterocyclic group having 5-7 ring atoms wherein 1-3 heteroatoms selected from the group O, N and S are present,R.sub.1 is hydrogen or fluoro,R.sub.2 is C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy or an oxo group, and p is 0, 1 or 2,Z represents carbon or nitrogen, and the dotted line represents a single bond when Z is nitrogen, and represents a single or double bond when Z is carbon,R.sub.3 and R.sub.4 independently are hydrogen or C.sub.1-4 -alkyl,n has the value 1 or 2,R.sub.5 is 2-pyridyl, 3-pyridyl or 4-pyridyl substituted at the meta-position with respect to the methylene bridge with a group Y, and optionally substituted with (R.sub.6)q,Y is a phenyl, furanyl or thienyl group, which groups may be substituted with 1-3 substituents from the group hydroxy, halogen, CF.sub.3, C.sub.1-4 -alkoxy, C.sub.1-4 -alkyl, cyano aminocarbonyl, mono- or di-C.sub.1-4 -alkylaminocarbonyl,R.sub.6 is halogen, hydroxy, C.sub.1-4 -alkoxy or C.sub.1-4 -alkyl, and q is 0, 1, 2 or 3 and salts thereof, are disclosed.