abstract |
The Invention provides a compound of formula (I), (where A, X, Y, Z, R3, R4, R5, R6, m and n are disclosed herein) or a pharmaceutically acceptable salt thereof (the compound or pharmaceutically acceptable salt thereof being a 'Piperazine Compound'); pharmaceutical compositions comprising an effective amount of a Piperazine Compound; and methods for treating pain, as well as other conditions, comprising administering to an animal in need thereof an effective amount of a Piperazine Compound. |