The present invention discloses a compound of formula: where Ar.sub.1, Ar.sub.2, X, Z.sub.1, Z.sub.2, R.sub.3, and m are as disclosed herein or a pharmaceutically acceptable salt thereof (a "Pyridylene Compound"); compositions comprising an effective amount of a Pyridylene Compound; and methods for treating or preventing pain or other conditions in an animal comprising administering to an animal in need thereof an effective amount of a Pyridylene Compound.