The present invention relates to nitrooxyderivatives or salts thereof having the following general formula (I): R—NR1c—(K)k0—(B)b0—(C)c0—NO2  (I) wherein c0, b0 and k0 are 0 or 1; R is the radical of an analgesic drug for chronic pain, for instance neurophatic pain; R1c is H or alkyl with from 1 to 5 carbon atoms; B is such that its precursor is selected from amino acids, hydroxy acids, polyalcohol, compounds; C is a bivalent radical containing an aliphatic, heterocyclic or aromatic radical.