摘要:
Disclosed are compounds of formula (I) wherein Z1 is -CH2- or -C(O)-, R4 and R5 are carbon chains (and optionally, together can form a C2 bridge), u and v are independently an integer of 0-3 such that there sum is from 3 to 5, and R2 is heteroaryl, and R1 and R3 are as defined herein. Also disclosed are methods of treating pain using a compound of formula (I).