Novel heterocyclic compounds having the Formula I: wherein A, B, D, E, G, K, L, M, Q, T, X, Y and Z are as defined herein, which exhibit a dopamine receptor (preferably a D4 receptor) agonistic activity, and/or a PDE5 inhibitory activity, processes of preparing same, pharmaceutical compositions containing same and uses thereof in the treatment of sexual disorders such as decreased libido, orgasm disorder and erectile dysfunction are disclosed.